Chapter 5
Chronic Diseases: Causes, Treatment, and Prevention

The Centers for Disease Control and Prevention (CDC) define chronic diseases as prolonged illnesses that do not resolve spontaneously and are rarely cured completely. According to the CDC, chronic illnesses such as cardiovascular disease, cancer, respiratory disease, cerebrovascular disease, and diabetes account for 70% of all deaths in the United States and almost half of the years of potential life lost before age sixty-five.

CARDIOVASCULAR DISEASES

Cardiovascular disease, which includes coronary heart diseases, arrhythmias, diseases of the arteries, congestive heart failure, rheumatic heart disease, cerebrovascular disease (stroke), and congenital heart defects, is the leading cause of death in the United States. The National Heart Lung and Blood Institute (NHLBI) reports that in 2002 cardiovascular disease accounted for 927,000 deaths—38% of all deaths—and cerebrovascular disease, the third-leading cause of death after cancer, accounted for 163,000 deaths (NHLBI Fact Book, Fiscal Year 2004, February 2005, http://www.nhlbi.nih.gov/about/04fackbk.pdf). Heart disease is second only to all cancers combined in terms of death rate and years of potential life lost. (Table 5.1.)

According to the NHLBI, one in four Americans—more than seventy million people in the United States—had cardiovascular disease. (See Table 5.2.) The American Heart Association (AHA) reports in Heart Disease and Stroke Statistics—2005 Update (http://www.americanheart.org/downloadable/heart/1105390918119HDSStats2005Update.pdf) that almost twenty-six hundred Americans die of cardiovascular disease each day—an average of one death every thirty-four seconds.

Heart Attack and Angina Pectoris

A heart attack, or myocardial infarction (MI), occurs when the blood supply from a coronary artery to the heart muscle (the myocardium) is cut off abruptly. This happens when one of the coronary arteries that supply blood to the heart is obstructed (blocked). When the blood supply is eliminated, the heart's muscle cells are deprived of oxygen and die. Disability or death can result, depending on how much of the heart muscle has been damaged.

Angina pectoris is not a disease; it is a symptom and the name for chest pain or pressure that occurs when poor blood flow through a partially occluded (blocked) artery to the heart sharply and temporarily reduces its supply of oxygen. When the blood flow is restored, the pain subsides. A common condition, angina is often a warning of the risk of heart attack. Its dull, constricting pain typically occurs when an individual is physically active or excited but subsides when activity ceases. In men, angina usually occurs after the age of fifty, whereas women tend to develop angina later in life. According to the AHA, in 2003 an estimated 13.2 million people in the United States suffered from angina. According to the Framingham Heart Study—a landmark study of heart disease in the residents of Framingham, Massachusetts, over the course of a half-century (http://www.nhlbi.nih.gov/about/framingham/)—about 350,000 new cases of angina occur annually.

WARNING SIGNALS OF A HEART ATTACK

The AHA names several warning signs of a heart attack:

• An uncomfortable pressure, squeezing, fullness, or pain in the center of the chest behind the breastbone
• Pain that spreads to the shoulders, neck, or arms
• Chest discomfort accompanied by sweating, nausea, shortness of breath, or a feeling of weakness

IMMEDIATE CARE IS CRUCIAL

Immediate medical care dramatically improves the odds of surviving a heart attack. Treatments are most effective if given within an hour of when the attack begins. According to the AHA, intensive emergency care in the first twelve hours after a

heart attack improves the patient's chance of survival and recovery. Researchers believe that patients who suffer heart attacks benefit from early intensive treatment—such as improved monitoring of their conditions and aggressive use of pharmacologic (drug) therapy, including appropriate reperfusion therapies—"clot-busting" medications—initiated with as little delay as possible. There are a variety of drugs that dissolve clots, but tissue plasminogen activator (tPA), which was approved by the Food and Drug Administration (FDA) in 1996, is currently used most often.

Treatments for Heart Disease

Once it is clear that a person is having a heart attack, immediate treatment usually includes administering drugs to help open the blocked artery, which restores blood flow to the heart and prevents clots from forming again. If the patient gets to an emergency room quickly, "reperfusion" might be done. In addition to administration of drugs to promote reperfusion, patients with heart disease also may undergo other procedures including:

• Balloon angioplasty or percutaneous transluminal coronary angioplasty (PTCA) to widen narrowed arteries with an inflated balloon
• Placement of wire mesh tubes, called stents, into arteries after angioplasty to prevent later collapse or restenosis (renarrowing)
• Coronary artery bypass graft surgery (CABG) to improve blood supply to parts of the heart muscle that have decreased blood flow

Once emergency care and immediate treatment is completed, most communities have cardiac rehabilitation programs to help people recover from a heart attack and reduce the chances of having another one.

Bypass Surgery

CABG, commonly known as "bypass surgery," can improve blood flow to the heart, relieve chest pains, and help the heart pump more efficiently. Generally, a segment of a large healthy vein, usually taken from the patient's leg, is spliced between the aorta (the main vessel carrying blood from the left side of the heart to all the arteries of the body and limbs) and the blocked coronary arteries. The coronary bypass operation thus supplies blood to the area of the heart that had a deficient blood supply. During the operation the patient is placed on a heart-lung machine that takes over the function of the heart and lungs while the surgery is proceeding. Usually, patients recovering from CABG surgery spend two or three days in the intensive care unit and several days to one week in the hospital following the surgery. The AHA reports in Heart Disease and Stroke Statistics—2005 Update that in 2002 about 515,000 coronary artery bypass surgeries were performed on 306,000 patients in the United States.

The AHA also reports that from 1979 to 2002 the total number of cardiovascular operations and procedures increased by 470%, in part because of the development of new procedures. For example, heart surgeons have developed a procedure called "minimally invasive direct coronary bypass" surgery. In this procedure the surgeon makes one or more small incisions (about three inches long) in the chest wall and works directly on the clogged artery while the heart is beating. Some surgeons use fiberoptic techniques similar to those used in gallbladder and other procedures. Anesthesiologists slow the heartbeat with drugs such as calcium channel blockers and beta-blockers to allow surgeons more control. Another technique actually stops the heartbeat and uses a modified heart-lung machine connected to a large artery in the groin while the surgeon operates through small incisions using a video camera and long-handled instruments.

Research studies have found that minimally invasive procedures have delivered the anticipated benefits including shorter recovery times, less time spent in the hospital, and the possibility of combining the new procedure with angioplasty or other procedures. As of 2006, however, no long-term follow-up data are available to substantiate the enduring benefits of these procedures. The long-term utility and success of the procedures will depend on post-procedure quality of life and survival rates for patients (John D. Puskas et al, "Clinical Outcomes, Angiographic Patency, and Resource Utilization in 200 Consecutive Off-Pump Coronary Bypass Patients," Annals of Thoracic Surgery, vol. 71, May 2001).

Catheter-based Interventions

Some patients qualify for much simpler procedures called "catheter-based interventions" because the procedures are performed via a thin tube inserted into an artery, rather than operating on the coronary artery by cutting through the chest wall. One such catheter-based intervention, performed under a local anesthetic, is PTCA (percutaneous transluminal coronary angioplasty), also called balloon angioplasty. A physician punctures an artery in the patient's groin and threads a balloon-tipped catheter into the artery. The tip of the catheter is slowly advanced up through the arterial system and positioned in the coronary artery at the point of the blockage or stenosis (narrowing). The small, sausage-shaped balloon on the end of the catheter then is inflated, flattening the fatty plaque and widening the artery. The balloon sometimes is inflated and deflated several times to clear the artery.

PTCA has several obvious advantages over bypass surgery. First, it is performed under a local rather than a general anesthetic and does not involve opening the chest or using a heart-lung machine. It is less expensive, and the patient is usually out of the hospital and recovering in a few days. Still, PTCA is not always completely effective, and nearly one-third of patients who have had PTCA eventually require bypass surgery or another PTCA because the initial procedure is unsuccessful or the blockage recurs.

According to the AHA in Heart Disease and Stroke Statistics—2005 Update, about 657,000 PTCA procedures were performed in the United States in 2002. Of these procedures, 66% were performed on men and about half were performed on people older than age sixty-five. From 1987 to 2002 the number of PTCA procedures performed increased 324 percent. The American College of Cardiology estimates that about one million angioplasties were performed in 2005.

As technology advances, catheter-based interventions using devices such as fiber optics and laser methods may replace angioplasty as the treatments of choice. Some physicians also are using a tiny cutting blade attached to the end of a fiber-optic tube to remove accumulated plaque, although this method has not yet been proven to be more effective than balloon angioplasty.

Physicians also are placing wire mesh tubes, called stents, into arteries after angioplasty to prevent later collapse or restenosis (renarrowing). However, even with stents, arteries renarrow in about 25% of patients. Physicians at the 2004 American College of Cardiology annual meeting reported greater success using drug-coated stents, which slowly release medication to prevent vessels from reclogging after procedures to open them. The cardiologists deemed them vastly superior to metal ones that were standard just a few years prior.

Benefits appear to last for years, and even big blockages in small vessels can be fixed using these stents. Some researchers suggest that the devices work so well that when an older stent clogs, it is considered preferable to put a new drug-coated one inside it than to treat the problem with radiation as has been done in the past (Marilynn Marchione, "Drug-Coated Stent Devices Making Strides in Heart Care," Associated Press/washingtonpost.com, March 7, 2005, http://www.washingtonpost.com/wp-dyn/articles/A12390-2005Mar6.html).

HEART TRANSPLANTS

Dr. Christiaan Barnard of South Africa performed the first successful heart transplant in December of 1967; that feat was repeated one month later in the United States by Dr. Norman Shumway at Stanford University Hospital in California. According to the United Network for Organ Sharing (UNOS) on their Organ Procurement and Transplantation Network (http://www.optn.org/latestData/rptData.asp), 2,127 heart transplants were performed in the United States during 2005. The percentage of Hispanic/Latino patients receiving heart transplants has grown from 4.7% in 1994 to nearly 8% in 2005, which is a reflection of the changing population of America. Those ages thirty-five to sixty-four years still receive most of the donated hearts (68%). Women make up 27% of heart transplant recipients, which is an increase of 3% from a decade ago.

The longest recorded survival of a heart transplant patient is about twenty-two years, and as of 2003 five-year survival was about 72%. According to UNOS, 2,999 patients were awaiting heart transplants in May 2006.

Risk Factors for Heart Disease

Various risk factors exist for heart disease; although some cannot be changed, others can be modified.

UNCHANGEABLE RISK FACTORS

Four risk factors for heart disease that cannot be altered are heredity, race, gender, and increasing age. People whose parents had or have cardiovascular diseases are more likely to develop them. Race is also a significant factor—African-Americans, for instance, are twice as likely as whites to have high blood pressure, which increases the risk for heart disease. Men have a greater risk of heart attack than do women—whereas heart attacks are the leading cause of death among men older than the age of forty, heart disease is not a major cause of death among women until they reach the age of sixty. Heart attacks also are more likely to occur as a person ages. More than half of the Americans who experience heart attacks are age sixty-five or older. Of those who die from their attacks, the vast majority are older than age sixty-five.

CHANGEABLE RISK FACTORS

Cigarette smoking doubles the risk of heart attack. A smoker who suffers a heart attack is more likely to die from it and more likely to die suddenly than a nonsmoker. Once people stop smoking, however, regardless of the length of time or the amount they have smoked, the risk of heart disease decreases significantly. The prevalence of cigarette smoking declined dramatically from 1965 to 1997 and then slowly decreased from 24.7% in 1997 to 20.9% in 2004. (See Figure 5.1 and Figure 5.2.) Although smoking among high school students increased during the early 1990s, teen smoking also declined from 1997 to 2003. (See Figure 5.1.) Still, despite the decline in smoking, the American Lung Association reported in 2006 (http://www.lungusa.org/site/apps/s/content.asp?c=dvLUK9O0E&b=34706&ct=66713) that approximately 438,000 Americans die each year of smoking-related illnesses, and most of these deaths are from cardiovascular causes. Worldwide, about five million people die prematurely each year from smoking.

High blood pressure, which usually has no symptoms or warning signs, is called the "silent killer." High blood pressure means that it is more difficult for blood to pump through the arteries, which increases the heart's workload, causing it to weaken and enlarge over time. Generally, blood pressure increases with age. Men have a higher incidence of high blood pressure than women do until about age fifty-five, when the risks become equal for both sexes. High blood pressure is a major problem for older women—more than 50% of women older than age sixty-five have this risk factor. (See Table 5.3.) In the majority of cases, high blood pressure can be controlled through diet, exercise, and medication.

High blood cholesterol levels increase the risk of coronary heart disease. Reduction of dietary fat, especially artery-clogging saturated fat, can reduce blood cholesterol levels, as can exercise. Maintaining a healthy weight, eating a proper diet, and exercising also can enhance the effectiveness of cholesterol-lowering drugs.

Lack of physical exercise is also a risk factor for heart disease. Figure 5.3 shows that only about one-third of adults age eighteen and older engaged in regular leisure-time physical activity. Nonpoor adults were more likely (37%) than near poor (23%) or poor adults (25%) to report regular physical activity and about one-half of poor and near poor adults were inactive compared with less than one-third of nonpoor adults. For men and women, the percentage of adults that engages in regular leisure-time physical activity decreased with advancing age. Among adults of all ages—particularly among younger adults (ages eighteen to twenty-four) and older adults (age seventy-five and older)—women were less likely than men to engage in regular leisure-time activity. (See Figure 5.4.) The AHA recommends thirty to sixty minutes of aerobic exercise three or four times a week for maximum heart fitness. Even lower levels of regular activity, such as walking or gardening, can help to prevent cardiovascular disease.

Some research also links the risk of heart disease with stress levels, behavioral habits, and socioeconomic level. Many studies have indicated that the risk of death from heart disease is considerably greater for less-educated people than for more-educated people. There may be several reasons for this. For instance, people who are better educated usually have higher incomes, better access to health care, and greater knowledge of prevention techniques.

CONTRIBUTING FACTORS

Diabetes, or elevated blood glucose, affects cholesterol and triglyceride levels. The disease can sharply increase the risk of heart attack, especially when blood glucose is uncontrolled or poorly controlled. About 65% of deaths among people with diabetes result from heart disease and stroke, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK; http://diabetes.niddk.nih.gov/dm/pubs/statistics/index.htm). Adults with diabetes have heart disease death rates that are two to four times higher than adults without diabetes.

Obesity is also a factor contributing to heart disease. Research has shown that the location of body fat may affect the risk of suffering a heart attack significantly. Men with a waist measurement that exceeds their hip measurement ("pot bellies," or excessive abdominal fat) and women whose waistline measurement is more than 80% of their hip dimension (apple-shaped) are at greater risk. Although obesity is directly associated with increased risk for cardiovascular disease, being overweight to any degree strains the heart.

The prevalence of obesity among adults age twenty and older in the United States has increased from 19.4% in 1997 to 25.6% in 2005. (See Figure 5.5.) Although the prevalence of overweight and obesity has increased in both males and females in all racial and ethnic groups, non-Hispanic white women were less likely to be obese than Hispanic and non-Hispanic African-American women; obesity was highest among non-Hispanic African-American women (35.8%). (See Figure 5.6.)

Prevalence of Heart Disease and Mortality Vary

In 2003 about 685,000 people in the United States died from heart disease, the leading cause of death in America. (See Table 5.4.) In 2002 the age-adjusted death rate for heart disease was 59% lower than the rate in 1950. Table 5.5 shows that in 2002 the age-adjusted death rate for heart disease was highest among African-American males (371 per one hundred thousand) and white males (294.1 per one hundred thousand), and lowest among Asian/Pacific Islander females (108.1 per one hundred thousand) and American Indian/Alaska Native females (123.6 per one hundred thousand). The death rate for white females from heart disease was 192.1 per one hundred thousand, whereas African-American females had a heart disease death rate of 263.2 per one hundred thousand.

According to the CDC, if all forms of major heart disease were eliminated, average life expectancy would increase by almost seven years. The AHA reports in Heart Disease and Stroke Statisics—2006 Update (http://www.americanheart.org/downloadable/heart/1136308648540Statupdate2006.pdf) that between 1993 and 2003 the death rates from heart disease declined 22.1%. The death rates in 2003 from cardiovascular disease were 359.1 per one hundred thousand for white males and 256.2 per one hundred thousand for white females. That same year the death rates from heart disease were 479.6 for African-American males and 354.8 for African-American females; these numbers are much higher than the cardiovascular disease death rate for the total population in 2003—for every one hundred thousand

people in the United States in 2003, about 309 people died from heart disease.

Based on the Framingham Heart Study, the AHA reported that in people younger than age seventy-five, more cardiovascular disease results from coronary heart disease (acute and chronic ischemic heart disease, angina, and MI) in men, whereas women suffer more from congestive heart failure (when the heart's pumping action is impaired to the degree that it is less than adequate). Although heart attacks are most prevalent among older people, they also occur in younger people; in 2001 about 25% of deaths in the forty-five- to sixty-four-year-old age group was from heart disease. Nevertheless, about four of five people who die of heart attacks are older than age sixty-five.

Women and Heart Disease

Until the early 1990s, almost all research on heart disease was carried out on middle-aged men. However,

heart disease affects women, too. When a woman enters menopause, she begins to lose the protection provided by the hormones that appear to reduce the risk of heart disease. As a result, the rates of coronary heart disease are two to three times higher among postmenopausal women than among premenopausal women, according to the AHA. One in three women older than age sixty-five suffers from some form of cardiovascular disease.

In fact, starting at age seventy-five, the prevalence of cardiovascular disease is higher among women than among men of the same age group, the AHA reports. Of women who have heart attacks, 38% die within the first year, compared with 25% of men. In part because women have heart attacks at older ages than men do, they are more likely to die from one within a few weeks of its occurrence. The occurrence of a second heart attack during the six years following the initial attack is 35% for women; within six years 11% will have a stroke, 6% will experience sudden cardiac death, and 46% will have disabling heart failure. Among African-American women thirty-five to seventy-four years of age, the death rate from coronary heart disease is about 70% higher than it is for white women.

Women are more seriously affected by heart disease than men are because women have smaller arteries, they frequently wait longer to get care, and they are generally older (typically by ten years) when heart disease strikes. Another reason could be that women's early symptoms of heart disease often differ from those of the "classic" heart attack. According to a study entitled "Women's Early Warning Symptoms of AMI" published in the November 2003 issue of Circulation: Journal of the American Heart Association, symptoms that often occur in women before a heart attack are (in order of frequency): unusual fatigue, sleep disturbance, shortness of breath, indigestion, and anxiety. Symptoms that may occur during a heart attack are comparable to the symptoms men experience: shortness of breath, weakness, unusual fatigue, cold sweat, and dizziness.

Women also undergo fewer cardiac procedures than do men. There also has been research demonstrating that anticlotting drugs, originally formulated for men, do not offer women comparable benefits. Finally, women may underestimate their vulnerability to heart disease. According to the AHA, surveys reveal that women fear breast cancer more than cardiovascular disease, even though more women die as a result of cardiovascular disease (one in 2.5 deaths) than from breast cancer (one in thirty deaths).

Rates of Treatment of Heart Disease Have Increased But Still Need Improvement

The January 2006 issue of Circulation (L. Kristen Newby et al, "Long-Term Adherence to Evidence-Based

Secondary Prevention Therapies in Coronary Artery Disease") reported that between 1995 and 2002 the percent of patients with coronary artery disease that was prescribed and used pharmacological agents that have proven survival benefits, such as daily aspirin, increased each year. Nonetheless, the report found that many patients are still not using these drugs on a consistent basis. For example, just 71% of patients used aspirin consistently. The researchers lamented this low rate of the use of aspirin and other effective therapies to improve survival, observing, "For a drug that is well-understood, inexpensive, easily available and fairly well-tolerated, we should see rates in the upper 90%." An editorial in the same issue of the journal (Sidney C. Smith, Jr., "Evidence-Based Medicine: Making the Grade—Miles to Go before We Sleep") noted that while progress has been made "most patients still do not receive the comprehensive medical therapies that can dramatically improve cardiovascular outcomes. If we are to recognize the true potential of these therapies, we must … provide the

necessary focus and resources to see that remaining gaps in therapy are eliminated for all sociodemographic groups."

Stroke

Stroke (cerebrovascular disease) is a cardiovascular disease that affects the blood vessels of the central nervous system. When an artery supplying oxygen and nutrients to the brain bursts or becomes clogged with a blood clot, a part of the brain does not receive the oxygen it needs. Without the necessary oxygen, the affected nerve cells die within moments. The parts of the body controlled by these nerve cells also become dysfur ctional. Because dead brain cells cannot be replaced, the damage done by a stroke is often permanent.

Stroke affects people in different ways. The extent of the resulting damage or loss depends on the type of stroke and the area of the brain that has been damaged. Physicians often can identify the location of a stroke in the brain from the symptoms and deficits observed during a neurologic examination, even before an imaging study (computed tomography or magnetic resonance imaging) confirms the region of the brain affected. The senses, speech, the ability to understand speech, behavioral patterns, thought, and memory are affected most frequently. The most common effect is for one side of the body to become paralyzed or severely weakened. A loss of sensation or vision as the result of the stroke can result in a loss of awareness of the affected parts, so many stroke victims may forget or "neglect" the parts of the body that are weakened or paralyzed. Falls, bumping into objects, or dressing only one side of the body tend to result from this sudden lack of awareness.

INCIDENCE OF STROKE DEATHS IS DECLINING

Stroke is the third-leading cause of death in America, following heart disease and cancer. (See Table 5.4.) The CDC reports that each year about five hundred thousand people suffer a new stroke and two hundred thousand have a recurrent stroke. An estimated 157,689 Americans died of stroke in 2003. (See Table 5.4.) According to the Framingham Heart Study, about 22% of men and 25% of women who have a stroke die within the first year.

The AHA reports that from the early 1970s to the early 1990s, the estimated number of noninstitutionalized stroke survivors increased from 1.5 million to 2.4 million. Nonetheless, stroke accounted for about one of every fifteen deaths in the United States in 2003 and was the underlying or contributing cause of death for about 273,000 persons. Because women live longer than men, more women die of stroke each year. In 2003 women accounted for 61% of U.S. stroke deaths, the AHA also reported (http://www.americanheart.org/presenter.jhtml?identifier=3037185).

The death rate for stroke declined substantially between 1950 and 2002. (See Figure 5.7.) The decrease in the number of stroke victims occurred at about the same rate for both sexes and for both African-Americans and whites. Nevertheless, as shown in Table 5.6, in 2002 the age-adjusted death rate for stroke was substantially higher among African-Americans (76.3 per one hundred thousand) than among whites (54.2 per one hundred thousand), American Indian or Alaska Natives (37.5 per

one hundred thousand), Asian or Pacific Islanders (47.7 per one hundred thousand), and Hispanic or Latinos (41.3 per one hundred thousand).

The two blood thinners heparin and warfarin are often used to reduce the chance of blood clot and recurrent strokes, although these drugs pose some risk of bleeding problems. Clinical trials have shown that the drugs are safe if their use is closely monitored. Another drug, tissue plasminogen activator (tPA), is a "clot-busting drug" approved specifically for fighting strokes. tPA, which became available in 1996, must be administered within three hours after the onset of a stroke. The drug works to stop the swift advance of damage caused by clots shutting off blood flow to the brain, which accounts for four-fifths of strokes. Early detection and immediate treatment is vital for tPA treatment to be optimally effective. Regular, low doses of aspirin also have proved effective in preventing stroke.

REHABILITATION FOR STROKE SURVIVORS

Stroke is a leading cause of serious long-term disability. The AHA asserts that stroke accounts for more than half of all patients hospitalized for acute brain diseases. According to Kate Hardie et al in "Ten-Year Risk of First Recurrent Stroke and Disability after First-Ever Stroke in the Perth Community Stroke Study" (Stroke, vol. 35, no. 3, February 5, 2005), the risk of first recurrent stroke is six times greater than the risk of first-ever stroke in the general population of the same age and sex, almost one half of survivors remain disabled, and one seventh require institutional care.

Many survivors lose mental and physical abilities and need expensive, lengthy, and intensive rehabilitation to regain their independence. In some cases independence is not achievable. Stroke can affect virtually all senses and perception, and patients who have had a stroke may find even familiar surroundings incomprehensible. They may be unable to recognize or understand well-known objects or people. The simplest activities become difficult, and depression is a common problem because patients who have had a stroke may feel overwhelmed and develop a sense of despair.

According to the National Institute of Neurological Disorders and Stroke, the duration of recovery depends on the severity of the stroke. Between one-half and two-thirds of stroke survivors regain the ability to function independently, while 15% to 30% suffer permanent disability and 20% require institutional care.

In the Framingham Heart Study of cardiovascular disease, 31% of stroke survivors needed help taking care

of themselves, 20% required help walking, and 71% had some type of impaired vocational ability when examined seven years after the occurrence of their strokes. Sixteen percent needed to be institutionalized.

Spontaneous recovery in the initial thirty days after a stroke probably accounts for the highest levels of regained functional ability. Rehabilitation to reduce dependency and improve physical ability, however, is

also vital. The patient's attitude, the skills of the rehabilitation team, and support and understanding from the patient's family all affect the quality of recovery.

NATIONAL COSTS OF STROKE

The costs of stroke are high in terms of emotional distress, lost wages, and medical care expenditures. The AHA estimated that the costs of stroke were nearly $58 billion in 2006, including the costs

of hospitalization, nursing home service, doctors' and nurses' services, medications, and lost productivity. Most of these costs were associated with health care facilities that provide long-term rehabilitation or residential care (Robert Adams et al, "American Heart Association/American Stroke Association Scientific Statement," May 2006).

High Blood Pressure

Blood pressure is a combination of two forces: the heart pumping blood into the arteries and the resistance of small arteries called arterioles to the flow of blood. The greater the resistance, the greater the pressure needed by the heart to keep the blood moving. The walls of the arterioles are elastic enough to allow for the expansion and contraction caused by the constantly changing rate of blood flow, thus allowing for a steady blood pressure in normal bodies. If the arterioles stay contracted or lose their elasticity as a result of atherosclerosis (commonly known as "hardening of the arteries"), the resistance to blood flow increases and blood pressure rises.

Blood pressure is measured in millimeters (mm) of mercury (Hg) by an instrument known as a sphygmomanometer. The sphygmomanometer produces two values: the systolic pressure (a measurement of the maximum pressure of the blood flow when the heart contracts or beats) and the diastolic pressure (the minimum pressure of the blood flow between beats). A typical "normal" range of values may vary, but the more resistance there is to blood flow, the higher the reading. High blood pressure (hypertension) for adults is defined as a systolic pressure equal to or greater than 140 mm Hg and/or a diastolic pressure equal to or greater than 90 mm Hg. In the United States nearly one in three adults has high blood pressure. "Prehypertension" is defined as systolic pressure of 120-139 mm Hg or diastolic pressure of 80-89 mm Hg. About two-thirds of individuals age forty-five to sixty-four and 80% of those age sixty-five to seventy-four have prehypertension ("Prehypertension Accounts for a Substantial Number of Hospitalizations, Nursing Home Admissions, and Premature Deaths," Agency for Healthcare Quality, April 2005).

Elevated blood pressure causes the heart to work harder than normal and places the arteries under a strain that might contribute to a heart attack, stroke, or atherosclerosis. When the heart works too hard, it can become enlarged and eventually will be unable to function at maximum pumping capacity.

PREVALENCE OF HYPERTENSION

As many as one in five Americans, including children as young as age six, have high blood pressure, according to the AHA. The cause of hypertension is unknown in 90% to 95% of cases; this is called essential hypertension. The remaining cases are termed secondary hypertension because they result from an identified condition, such as an abnormality in the kidneys, adrenal gland, or aorta.

The AHA reports that African-Americans, Puerto Ricans, Cuban Americans, and Mexican Americans are more likely to suffer from hypertension than whites. Table 5.3 shows data about high blood pressure among people twenty years of age and older by race, poverty status, and Hispanic origin. In the period 1999–2002 hypertension was more prevalent among the poor (19.3%) and near poor (19.5%) than among the nonpoor (14.9%). Both African-American males and African-American females have a higher incidence of high blood pressure than white or Mexican American males and females.

The AHA reports that in 2003 hypertension was either the primary cause of death or contributed to the death of about 277,000 Americans. From 1993 to 2003 the age-adjusted death rate from hypertension increased by nearly 30%, and the actual number of deaths rose 56.1%. As many as 30% of all deaths among African-American men with hypertension and 20% of all deaths among African-American women with hypertension can be attributed to high blood pressure (Heart Disease and Stroke Statisics—2006 Update).

TREATMENT

In almost all cases, hypertension is treatable. A variety of medications, including diuretics, which rid the body of excess fluid and salt, can lower blood pressure.

Diet and lifestyle changes are also essential to control hypertension. Some people with only mildly elevated blood pressure need only to reduce or eliminate salt in their diets. Blood pressure in overweight or obese people often declines when they lose weight. Heavy drinkers often see improved blood pressure when they abstain from alcohol or drink less. Some people find exercise, stress management techniques, and relaxation therapy helpful. When people are aware of the problem and follow prescribed treatments, high blood pressure can be controlled and need not be fatal. Patients, however, often stop taking high blood pressure medication once their hypertension is controlled. This poses a serious danger; it is essential that patients continue to take the medication even if they feel perfectly well.

CANCER

Cancer is a large group of diseases characterized by the uncontrolled growth and spread of abnormal cells. These cells may grow into masses of tissue called tumors. Tumors made up of cells that are not cancerous are called benign tumors. The tumors consisting of cancer cells are called malignant tumors. The dangerous aspect of cancer is that cancer cells invade and destroy normal tissue.

The spread of cancer cells occurs either by local growth of the tumor or by some of the cells becoming detached and traveling through the blood and lymph systems to start additional tumors in other parts of the body. Metastasis (the spread of cancer cells) may be confined to a region of the body, but left untreated (and often despite treatment), the cancer cells can spread throughout the entire body, causing death. The rapid, invasive, and destructive nature of cancer makes it, arguably, the most

feared of all diseases, although it is second to heart disease as the leading cause of death in the United States.

What Causes Cancer? Who Gets Cancer? Who Survives?

Cancer may be caused by both external factors (chemicals, radiation, and viruses) and internal factors (hormones, immune conditions, and inherited mutations). These factors act together or in sequence to begin or promote cancer.

It seems no one is immune to cancer. Because the incidence increases with age, most cases are found among adults in midlife or older. However, cancer is the second-leading cause of death in the United States among children ages five to fourteen, according to the CDC. The American Cancer Society (ACS) estimates that about one out of every two men and one out of every three women in the United States will have some type of cancer at some point during their lifetime.

According to ACS estimates in Cancer Facts and Figures, 2005 (http://www.cancer.org/downloads/STT/CAFF2005f4PWSecured.pdf), nearly 1.4 million people (710,040 men and 662,870 women) were diagnosed with cancer in 2005 and 570,380 died of cancer—more than 1,500 people a day. In the United States, cancer causes one of every four deaths and the death rates for most forms of cancer have remained fairly steady since the 1930s. Three exceptions are lung, stomach, and uterine cancer. In the 1930s stomach cancer and uterine cancer had some of the highest death rates, but they have since declined to some of the lowest. Meanwhile, the lung cancer death rate increased dramatically from 1930 up until 1990, especially for men, then began to decline.

The ACS also reports that many patients with cancer do survive for some time after diagnosis. From 1995 to 2000 about 64% of patients diagnosed with cancer had

survived for at least five years after their cancers were diagnosed, up from about 50% between 1974 and 1985. Further, fifty years ago fewer than one in four patients treated for cancer were still living after five years. Approximately ten million Americans have a history of cancer. Many of these individuals are considered "cured," meaning that there is no evidence of the disease and survivors have life expectancy comparable to persons who have never had cancer.

Recent research reveals that long-term survivors of childhood cancers are at increased risk for limitations in physical performance and are likely to have difficulty with certain activities of daily living. Investigators from the University of Minnesota in Minneapolis analyzed data from 11,481 subjects who were diagnosed with cancer before age twenty-one and survived at least five years (Kirsten Ness et al, "Limitations on Physical Performance and Daily Activities among Long-Term Survivors of Childhood Cancer," Annals of Internal Medicine, vol. 43, no. 9, November 1, 2005). Survivors were 80% more likely than their siblings to report performance limitations and at least four times more likely to describe restricted participation in routine activities including the ability to attend school or work.

The survivors most likely to report performance limitations, restrictions in routine activities, and difficulty attending school or work were those with brain and bone cancers. Not surprisingly, brain cancer survivors were more likely than other survivors to report impairments in performing personal care. The investigators observed that while some treatment for childhood cancers is known to cause functional limitations, the prevalence of these problems and their relationship to cancer type and treatment received remained unclear.

BEHAVIORAL AND ENVIRONMENTAL RISK FACTORS CONTRIBUTE TO CANCER DEATHS

Researchers at the Harvard School of Public Health collaborated with more than one hundred scientists around the world to estimate mortality for twelve types of cancer linked to nine risk factors in 2001. They found that of the seven million cancer deaths worldwide, 35% were attributable to the nine potentially modifiable behavioral and environmental risk factors—overweight and obesity, low fruit and vegetable intake, physical inactivity, smoking, alcohol use, unsafe sex, urban air pollution, indoor smoke from household use of coal, and contaminated injections in health care settings (G. Danaei, S. Vander Hoorn, A. Lopez, C. Murray, M. Ezzati, "Causes of Cancer in the World: Comparative Risk Assessment of Nine Behavioral and Environmental Risk Factors," Lancet, vol. 366, no. 9499, November 19, 2005).

Worldwide, the nine risk factors caused 1.6 million cancer deaths among men and 830,000 among women. Smoking alone was estimated to have caused 21% of deaths from cancer worldwide. Smoking, which is linked to lung, mouth, stomach, pancreatic, and bladder cancers, is the biggest avoidable risk factor, followed by alcohol and not eating enough fruit and vegetables. In high-income countries these nine risks caused 760,000 cancer deaths; smoking, alcohol, and overweight and obesity were the most important causes of cancer in these nations.

In low- and middle-income regions the nine risks caused 1.67 million cancer deaths; smoking, alcohol consumption, and low fruit and vegetable intake were the leading risk factors for these deaths. Sexual transmission of human papillomavirus (HPV) is the leading risk factor for cervical cancer in women in low- and middle-income countries, particularly in Sub-Saharan Africa and South Asia, mainly because access to cervical cancer screening is limited.

The investigators concluded that "these results clearly show that many globally important types of cancer are preventable by changes in lifestyle behaviors and environmental interventions. To win the war against cancer, we must focus not just on advances in biomedical technologies, but also on technologies and policies that change the behaviors and environments that cause those cancers."

The Seven Warning Signs

The ACS lists the following seven symptoms or changes as possible signals of cancer and indications to see a physician:

• Change in bowel or bladder habits
• A sore that does not heal
• Unusual bleeding or discharge
• Thickening or lump in breast or elsewhere
• Indigestion or difficulty swallowing
• Obvious change in wart or mole
• Persistent cough or hoarseness

Could More Americans Be Saved?

The ACS estimates that many more lives could be saved with early detection and treatment. Regular screening can detect cancers of the breast, tongue, mouth, colon, rectum, cervix, prostate, testis, and skin at early stages when treatment is more likely to be successful. Approximately one-third of all new cancers occur at these sites. More than three-quarters of all patients treated for these kinds of cancers currently survive five years or more. With early detection, the ACS points out that an estimated 95% could survive. For example, protecting skin from sunlight would prevent many of the one million skin cancers found annually. Further, the estimated 30% of all cancer deaths and 87% of lung cancer deaths as a result of cigarette smoking could be prevented.

Figure 5.8 shows that screening for breast cancer rose from 1987 and has stabilized at about 70% of women age forty and older reporting that they had received a mammogram within the past two years. The rate of breast cancer screening has met the target set by Healthy People 2010, the set of disease prevention and health promotion objectives established for the nation by the U.S. Department of Health and Human Services. In contrast, Figure 5.9 shows that the percentage of women age eighteen and older that reported receiving a Pap test to screen for cervical cancer within the past three years rose until 2000 but by 2003 had fallen slightly to 79%, 11% below the benchmark set by Healthy People 2010.

Some disparities in screening and prevention remain in terms of use of recommended screening tests among members of racial and ethnic minorities. The CDC's National Health Interview Survey (NHIS; http://progress-report.cancer.gov/summary-tables_female.asp) reported that in 2003, 65% of Hispanic women, 70% of African-American women, and 71% of white women had a mammogram within the past two years. Not surprisingly, the NHIS found that poor, less educated women who lack health insurance or a usual source of care were less likely to get screening mammograms. Similarly, while 79% of women age eighteen and older had been screened for cervical cancer within the past three years, just 75% of Hispanic women had received a Pap test, compared with 83% of African-American women and 80% of white women. Older, poor, less educated women were less likely to be screened for cervical cancer. At the same time older women are at greater risk than younger women of dying from cervical cancer.

Cancer among African-Americans

African-Americans are more likely to be diagnosed with cancer and to die from the disease than any other racial or ethnic population. Figure 5.10 shows that among the major racial and ethnic groups, African-Americans have the highest rate of new cases of all cancers. According to the ACS in Cancer Facts and Figures, 2005, the mortality rate from cancer among African-American males is 1.4 times higher than among white males; for African-American females it is 1.2 times higher. The difference in death rates is attributed to the fact that more whites than African-Americans have their cancers diagnosed at an earlier, localized stage (before the cancer had metastasized) when the chances for successful treatment and survival are best. Part of the problem may be lower levels of public awareness and use of cancer screening among African-Americans and other ethnic minorities. Other social and economic inequities, such as a lack of health insurance, transportation, or access to affordable health care, also may prevent or delay testing and timely treatment. Not all differences in cancer risks and rates between population groups result from inequities; some increased risk may be conferred by genetics. For example, genetic factors may contribute to the elevated risk of prostate cancer among African-American males.

Gender and Cancer

As previously mentioned, the ACS estimated that in 2005, 710,040 males and 662,870 females were diagnosed with cancer. Men and women are each more prone to certain types of cancer—most obviously, the cancers of the reproductive system such as ovarian and cervical cancer in women and prostate or testicular cancer in men. Breast cancer also occurs mainly in women, although some men do die from breast cancer as well.

Similarly, cancer claims more males than females. In 2002 there were 238.9 cancer deaths per one hundred thousand males compared with 163.1 per one hundred thousand females. The cancer death rates were higher among males of all ages. Even among those age eighty-five and older, cancer deaths were nearly twice as frequent among males as females. (See Table 5.7.)

Lung Cancer

The ACS estimated in Cancer Facts and Figures, 2005 that 172,570 new cases of lung cancer would be diagnosed in 2005, accounting for 13% of cancer diagnoses. Incidence of lung cancer increased until 1991, after which it declined slightly. The incidence of new cases of lung cancer in men has declined from a high of 102.1 per one hundred thousand in 1984 to 77.7 per one hundred thousand in 2001. However, for women, the incidence continued to increase during the same period, although it stabilized from 1998 to 2002. Figure 5.11 shows the rates of new cases of the four most common cancers and the leveling off of new cases of lung cancer that occurred from 1999 to 2003.

Lung cancer claimed an estimated 163,510 lives in 2005, accounting for 29% of all cancer deaths. Each year since 1987, more women have died of lung cancer than breast cancer, which had been the leading cause of cancer deaths for women for more than forty years. For men, lung cancer is also the leading cause of cancer-related deaths.

According to the ACS in Cancer Facts and Figures, 2005, the five-year survival rate for lung cancer is low—only 15%—but if lung cancer is detected in the early stages when it is still localized, the survival rate is 49%. Unfortunately, only 16% of all cases of lung cancer are detected early.

The main risk factor for lung cancer is cigarette smoking, especially a long history of smoking (twenty years or more). In addition, exposure to certain industrial substances, such as asbestos, organic chemicals, and radon, can increase the risk of developing the disease.

Passive, or involuntary or secondhand, smoking—inhaling other people's smoke—also increases the risk for nonsmokers. Research has determined that the risk to a nonsmoking woman who is married to a smoker is 30% greater than for a woman with a nonsmoking spouse. The Environmental Protection Agency (EPA) claims that an estimated three thousand nonsmokers die each year from secondhand-smoke-induced lung cancer (http://www.epa.gov/smokefree/healtheffects.html), and in 1993 the EPA added secondhand smoke to its list of known carcinogens.

Early diagnosis of lung cancer is difficult; by the time a tumor is visible on x-rays it is often in the advanced stages. If an individual, however, stops smoking before cellular changes occur, damaged tissues often return to normal. New diagnostic tests such as low-dose helical computed tomography (CT) scans, which provide detailed three-dimensional images of the lungs, and laboratory procedures that can detect cancer cells in sputum have demonstrated an ability to diagnose lung cancer earlier than conventional tests, and research to evaluate their effects on survival rates is under way. As of 2006, efforts to detect lung cancer earlier had not yet demonstrated the capacity to reduce mortality from the disease. The treatment options for lung cancer include surgery, radiation therapy, and chemotherapy (anticancer drugs).

Colon and Rectal Cancer

In 2005 an estimated 145,290 cases of colon and rectal cancers were diagnosed, and an estimated 56,290 people died of the diseases (Cancer Facts and Figures, 2005). The incidence of colorectal cancer increased slightly until 1985. It has declined steadily since then, except for a slight nonsignificant rise during the period 1995–98. (See Figure 5.11.)

When colon and rectal cancers are detected early, the five-year survival rates are 90%, according to the ACS. Only 38% of such cancers are found at this stage, however. If the malignancy has spread regionally, the five-year survival rate drops to 64%.

Colon cancer occurs most often in people without any known risk factors. However, people with a family history of polyps in the colon or rectum and people who have suffered from ulcerative colitis and other diseases of the bowel are considered to be at greater risk for developing the disease. Another significant risk factor may be a diet high in fat and low in fiber.

The ACS recommends a variety of screening tests to detect bowel cancer in its early stages. A digital rectal examination, performed by a physician during a routine office visit, is recommended annually for those older than forty years of age. For people older than age fifty, an annual stool test for fecal occult blood (hidden blood) is recommended, along with flexible sigmoidoscopy (examination of the lower colon and rectum using a hollow, lighted tube) every five years. Figure 5.12 shows that all testing for fecal occult blood—in home and in the physician's office—rose until 1998 then declined very slightly—essentially leveling off. The ACS also recommends an imaging procedure called a double-contrast barium enema, which provides a complete radiologic examination of the colon, every five years for people older than fifty years and a screening colonoscopy (examination of the entire colon, also referred to as colorectal endo-scopy) as often as recommended by the physician. Rates of colorectal endoscopy rose from 1987–98, and continued to rise from 1998–2003, with a statistically significant increase between 2000 and 2003. (See Figure 5.13.)

Despite overwhelming evidence that screening and early detection save lives, most adults do not receive even the simplest of the colon cancer screening tests. The CDC reports that nearly forty-two million Americans, age fifty and older, have not been screened appropriately for colorectal cancer. Figure 5.14 shows that the percentage of adults age fifty and older who had colorectal cancer tests within the recommended screening intervals varies throughout the United States, with the highest screening rates in the Northeast and the state of Minnesota. The CDC asserts that colorectal cancer screening remains underused, lagging far behind screening for breast and cervical cancers. Screening is lowest among people without health insurance or a usual source of health care and among those who had not been to the doctor within the preceding year.

In efforts to increase colorectal cancer screening among low-income adults age fifty and over who have little or no health insurance coverage for regular screenings, in September 2005 the CDC awarded more than $2 million in grant funding aimed at increasing screening in this population. The funding will enable five centers in Maryland, Missouri, Nebraska, New York, and Washington to establish demonstration projects to increase awareness and utilization of colorectal cancer screening. ("CDC Awards $2.1 Million to Establish Colorectal Cancer Screening Program," Atlanta, GA: Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, September 28, 2005, http://www.cdc.gov/nccdphp/press/colorectal_cancer.htm).

The most common treatment for cancer of the bowel is surgery to remove the diseased area, in combination with radiation. A colostomy (an opening in the abdomen to allow for waste elimination) is seldom necessary for patients with colon cancer but may be required for patients with rectal cancer. The ACS reports that only about 15% of all patients with rectal cancer require a permanent colostomy if the cancer is detected in the early stages. Of those who do require a permanent colostomy, most go on to lead normal, active lives. Chemotherapeutic agents used to treat metastatic (spreading) colon and rectal cancer include the drugs oxaliplatin with 5-fluourouracil followed by leucovorin.

Breast Cancer

Breast cancer is the most common form of cancer among women; an estimated 269,930 new cases—211,240 cases of invasive breast cancer and 58,490 new cases of in situ (noninvasive) breast cancer occurred in 2005 (Cancer Facts and Figures, 2005). An estimated 40,870 deaths resulted from breast cancer in 2005. The disease ranks second in terms of cancer deaths in women, after lung cancer.

The incidence of breast cancer steadily increased between 1980 and 1987 and has since risen minimally. (See Figure 5.11.) There appears to be only a slight, as yet unexplained, increase in breast cancer in recent years. (See Figure 5.15.) The slow growth may be attributed to increased utilization of screening mammography to detect tumors very early. In fact, the ACS estimates that 85% of new cases of in situ breast cancer diagnosed in 2005 was ductal carcinoma in situ (noninvasive cancer localized in the duct area)—a direct result of mammography's ability to detect early stage masses in the breast before they can be felt, and before the cancer progresses to an invasive stage.

The five-year survival rates for cancers of the breast are encouraging. The ACS reports that if the cancer is localized, the survival rate is 98%—up from 72% in the 1940s. If the cancer is undetected and has spread regionally, however, the survival rate decreases to 80%, and for women whose cancer has spread to distant parts of the body, the survival rate is only 26%.

The precise causes of breast cancer are still unknown. The disease is most common in women older than age fifty, and the risks are higher among women with a family history of breast cancer, those who have never had children, and women who gave birth to their first baby after age thirty. Other factors that may contribute to increased risk for breast cancer include having a longer-than-average menstrual history (menstruation beginning at an early age and ending late in life); being obese after menopause; consuming alcohol; and eating a high-fat diet.

As with other types of cancer, early detection is the key to cure and survival. The ACS recommends that all women age twenty and older be apprised of the benefits and limitations of performing breast self-examination each month. Mammography is an invaluable screening and diagnostic tool for detecting cancers that are too small to be otherwise discovered. The ACS recommends that women age thirty-five to thirty-nine have a baseline mammogram (that later can be compared with others), and those older than age forty should have routine mammograms each year. Clinical breast examinations also should be performed annually by a health care professional in women age forty and older, and women in their twenties and thirties should have a clinical breast examination at least every three years.

Recent research outlined in the New England Journal of Medicine confirmed the ability of mammograms to save lives. Seven statistical models showed that both screening mammography and treatment have helped reduce the rate of death from breast cancer in the United States. The researchers demonstrated that the usefulness of screening outweighs the risks, which include false positives and possibly needless treatment to remove tiny tumors that might never have caused a problem if left untreated (Donald Berry et al, "Effect of Screening and Adjuvant Therapy on Mortality from Breast Cancer," vol. 353, no. 17, October 27, 2005).

CHOICES OF TREATMENT

Breast cancer treatment remains a subject of continuing medical debate. If a breast contains cancerous tissue, the patient and her physician have four standard treatment options: surgery, radiation therapy, chemotherapy, or hormone therapy. Treatment choices depend on the location and size of the tumor, the stage of the cancer (whether the cancer has spread within the breast or to other parts of the body affects staging), and the size of the breast. A small, contained tumor can be removed in a procedure commonly called a lumpectomy (removal of the tumor, or "lump") and lymph node dissection (microscopic examination of lymph nodes to detect cancer cells), followed by radiation therapy to the whole breast. If the cancer is more advanced and invasive, removing the breast (mastectomy) and usually the adjoining lymph nodes, combined with chemotherapy or hormone therapy, may be the most effective treatment.

Two studies released in 1995 showed that both procedures were equally effective in appropriate cases. A ten-year study by the National Cancer Institute of 247 women who had been treated with lumpectomy and radiation for early cancers found that their survival and cancer recurrence rates were the same as those who had mastectomies. (The patients who had lumpectomies also were screened for lymph node cancer; if one or more nodes were cancerous, these women received combination chemotherapy in addition to radiation.) Ten years after treatment, more than 75% of the patients were still alive, and 70% had no recurrence of cancer. A twenty-year study by the National Tumor Institute in Milan, Italy, found that of 386 women who had mastectomies followed by combination chemotherapy, 34% had fewer relapses and 26% fewer died than those treated by mastectomy alone.

Some treatments are standard (the treatment used currently), and some treatments are being tested in clinical trials. A treatment clinical trial is a research study designed to help improve already-existing treatments or obtain information on new treatments for patients with cancer. If a clinical trial shows that a new treatment is better than the standard treatment, the new treatment then may become the standard treatment.

The drugs tamoxifen and raloxifene have been shown to decrease breast cancer risk when used as preventive measures by women at high risk of developing the disease. Tamoxifen was approved in 1998 for the prevention of breast cancer in high-risk but healthy women; it has been shown to reduce the risk of breast cancer in high-risk women by as much as 50%. Research has revealed that only a small fraction of those who are eligible—which is about 15% of the female population in the United States—are taking it. According to Dr. John Barstis of the UCLA Jonsson Comprehensive Cancer Center, physicians are reluctant to prescribe the drugs and many women are unwilling to take them—perhaps because of the problems found with hormone replacement therapy and subsequent reluctance to rely on preventive measures in which the benefits might or might not outweigh serious risks (Thomas H. Maugh II, "Breast Cancer Prevention Drug Outdone," Los Angeles Times, April 18, 2006).

Another study published challenged the standard practice of giving breast cancer survivors five years of tamoxifen therapy to prevent recurrence of the disease. In a report in the New England Journal of Medicine, women who switched to the drug exemestane after two or three years of taking tamoxifen were less likely to have a recurrence of cancer than women who continued taking tamoxifen the full five years. However, researchers caution that it is still too early to tell if a switch is worthwhile in all patients (R. C. Coombes et al, "A Randomized Trial of Exemestane after Two to Three Years of Tamoxifen Therapy in Postmenopausal Women with Primary Breast Cancer," vol. 350, no. 11, March 11, 2004).

The National Cancer Institute (NCI) reported that in 2002, 41% of women age twenty and older diagnosed with early-stage breast cancer received mastectomy, 37% received breast-conserving surgery plus radiation, and 19% received breast-conserving surgery only (Cancer Trends Progress Report—2005 Update, Rockville, MD: National Cancer Institute, Division of Cancer Control and Population Science, December 2005, http://progressreport.cancer.gov/). In 2006 the National Institutes of Health (NIH) guidelines recommended that women with positive lymph nodes receive multiagent chemotherapy, along with tamoxifen for those women with estrogen-receptor positive tumors, based on the results of numerous randomized controlled treatment trials. Figure 5.16 shows the increasing proportion of breast cancer patients with positive lymph nodes receiving multidrug chemotherapy treatment from 1987 to 2000.

Sentinel lymph node (SLN) biopsy is a form of treatment that was tested in two large clinical trials that compared SLN biopsy with conventional axillary lymph node dissection. The trials were conducted by the National Surgical Adjuvant Breast and Bowel Project and the American College of Surgeons Oncology Group—NCI-sponsored networks of institutions and physicians across the country that jointly conduct trials. This treatment is a surgical procedure involving the removal of the sentinel lymph node (the first lymph node the cancer is likely to spread to from the tumor) during surgery. Either a radioactive substance or a blue dye—in some cases both—is injected near the tumor. This flows through the lymph ducts to the lymph nodes. The first lymph node to receive the substance or dye is removed for biopsy. If cancer cells are not found, no more lymph nodes may need to be removed. After the sentinel lymph node biopsy, the surgeon performs lumpectomy or mastectomy to remove the tumor.

Peer and professionally facilitated support groups are available to help patients deal with the emotional consequences and physical side effects of breast cancer treatment. Newer techniques have made breast reconstruction possible—frequently during or immediately following surgery.

GENETIC RESEARCH

Physicians have known for some time that a predisposition to some forms of breast cancer is inherited. For this reason, physicians have been searching for the gene or genes responsible so that they can test patients and provide more careful monitoring for those at risk. In 1994 doctors identified the BRCA1 gene, and in late 1995 they also isolated the BRCA2 gene.

If a woman with a family history of breast cancer inherits a defective form of either BRCA1 or BRCA2, she has an estimated 80% to 90% risk of developing breast cancer. Researchers also think that the two genes are linked to ovarian, prostate, and colon cancer, and BRCA2 likely plays some role in breast cancer in men. Scientists suspect that the two genes also may participate in some way in the development of breast cancer in women with no family history of the disease. Only about 5% of all cases of breast cancer are attributable to defects in BRCA1 and BRCA2.

A study completed in November 1996, headed by Dr. Stephen C. Rubin, a professor and chief of gynecologic oncology (cancers of the female reproductive organs) at the University of Pennsylvania, reported a result that was totally unexpected. The study found that women with defective BRCA1 genes who developed ovarian cancer survived longer than those without the mutated gene who developed ovarian cancer. Women with the defective gene lived an average of seventy-seven months after diagnosis, whereas those without the mutated gene averaged only twenty-nine months. Researchers do not know if those with the defective gene had less deadly types of cancers or if their cancers responded better to treatment.

Another form of breast cancer, driven by multiple copies of a gene called HER-2, causes an estimated 30% of the new cases of the disease in the United States each year. HER-2/neu is an aggressive form of cancer that can cause death more quickly than other breast cancers, often within ten to eighteen months after the cancer spreads. The HER-2 gene produces a protein on the surface of cells that serves as a receiving point for growth-stimulating hormones.

Herceptin, a genetically engineered antibody drug, increases the benefits of chemotherapy by shrinking tumors and slowing the progression of HER-2/neu. Herceptin (also known as trastuzumab) became available in late 1998. By early 2006 promising therapies included treatment with the anti-HER2/neu antibody, trastuzumab—for patients with high levels of HER2 protein—and aromatase inhibitors. Many breast tumors are "estrogen sensitive," meaning the hormone estrogen helps them to grow. Aromatase inhibitors (AIs) help block the growth of these tumors by lowering the amount of estrogen in the body. In early 2006 there were three aromatase inhibitors approved by the FDA: anastrazole (Arimidex), exemestane (Aromasin), and letrozole (Femara).

Skin Cancer

Skin cancer is a common form of malignancy—one in five Americans will develop some form of skin cancer during their lifetime. According to the 2006 Skin Cancer Fact Sheet (http://www.aad.org/aad/Newsroom/2005+Skin+Cancer+Fact+Sheet.htm) by the American Academy of Dermatology (AAD), more than one million new cases of skin cancer will be diagnosed in 2006. The majority will be nonmelanoma types—basal or squamous cell cancers that can be easily cured. The AAD estimated that 111,900 new cases of malignant melanoma, a far more serious form of skin cancer, will be diagnosed in 2006. Data from the NCI shows that among whites, melanoma nearly tripled in incidence between 1975 (8.5 per 100,000) and 2003 (25 per 100,000). (See Figure 5.17.)

The AAD reported that an estimated 10,590 people died of skin cancer in 2005, with most of the deaths (an estimated 7,770) resulting from malignant melanoma (http://www.aad.org/aad/Newsroom/skincancerfact.htm). Melanoma can spread to other parts of the body quickly, but if it is detected early and properly treated, it is highly curable. The five-year survival rate for a localized malignant melanoma is 98%, and about 83% of melanomas are diagnosed at a localized stage.

Nearly three-quarters of skin cancer deaths are from melanoma. Invasive melanoma is the fifth most common cancer in men and the sixth most common cancer in women, according to the AAD. Among women ages twenty-five to twenty-nine, melanoma is more common than any non-skin cancer.

Simple precautions can prevent most skin cancers. Avoiding the sun between 10:00 a.m. and 4:00 p.m. (when the ultraviolet rays are the strongest), using sunscreens, and wearing protective clothing decrease the risk of skin cancer considerably. Figure 5.18 shows that while the percent of adults age eighteen and over who were very likely to protect themselves from the sun rose from 1998 to 2000, from 2000 to 2003 the level has remained stable, with less than two-thirds—well below the Healthy People 2010 target of 75%—reporting that they were very likely to use sunscreen, wear protective clothing, or seek shade.

Prostate Cancer

According to the ACS in Cancer Facts and Figures, 2005, an estimated 232,090 American men were diagnosed with prostate cancer in 2005. Approximately 30,350 men died from the disease in 2005, making it the second-leading cause of cancer death in men, exceeded only by lung cancer. The probability of developing prostate cancer increases with advancing age.

The incidence of prostate cancer rose sharply beginning around 1988. It peaked in 1992, then declined until 1995, after which it began to rise again. (See Figure 5.19.) Incidence rates for prostate cancer vary among racial and ethnic groups. Since the early 1990s, the rates of diagnosis and death from prostate cancer have been so much higher for African-American men that as a group they were almost twice as likely to develop and die from prostate cancer than any other racial and ethnic group. In fact, African-American and Jamaican men of African descent have the highest prostate cancer incidence rate in the world, according to the ACS.

During the late 1980s prostate-specific antigen (PSA) screening became available to test for the disease. This is a blood test that measures a protein made by prostate cells. PSA blood tests are reported in nanograms per milliliter (ng/mL). Results are considered normal if the reading is under 4 ng/mL; borderline results are between 4 and 10 ng/mL; and any reading of more than 10 ng/mL is high. The higher the reading, the more likely prostate cancer is present. However, normal levels increase with age, and older men with higher readings frequently are not found to have prostate cancer. For example, PSA levels greater than or equal to 2.5 ng/mL are considered abnormally high for men younger than age forty-nine, whereas PSA levels greater than or equal to 4.5 are considered abnormally high for men between the ages of sixty and sixty-nine years.

To help detect prostate cancer early, at a stage when it is most likely to be treated with success, a PSA blood test and a digital rectal examination should be offered once a year to men age fifty and older with a life expectancy of at least ten years. African-American men and men who have a first-degree relative who had prostate cancer should begin receiving these tests at age forty-five because they are at a higher risk of developing the disease. Prostate cancer screening has effectively reduced the rates of new cases of late-stage disease, which began a dramatic descent in the early 1990s, following the introduction of the PSA test. (See Figure 5.20.)

Prostate cancer may be treated in several ways, depending on the age of the patient, severity of the cancer, and any other medical conditions the patient may have. Radiation and surgery may be used if the disease is in an early stage. Hormone therapy (which shrinks the tumor, thus relieving pain and other symptoms for a long period), chemotherapy, and radiation may be used alone or in combination if the cancer has spread, and these methods may be effective as supplements to treatments during early stages. "Watchful waiting" (close observation with no treatment) also may be appropriate in patients who are older or who have less aggressive tumors.

A radical prostatectomy is the removal of the prostate and some of the tissue surrounding the gland. This is done when the cancer has not spread outside the gland. Radiation therapy kills cancer cells and shrinks tumors and may be used before or after prostate surgery. Impotence (erectile dysfunction) and urinary incontinence occur slightly more often when radiation is used following surgery. Radiation therapy can cause damage to the rectum.

Therapy to reduce hormone (testosterone) levels may be prescribed to limit prostate cancer cell growth. Patients may be given drugs such as LHRH (luteinizing hormone-releasing hormone) agonists, which decrease the amount of testosterone in the body, or antiandrogens, which block the activity of testosterone. These cause cancer cells to shrink because testosterone promotes the growth of prostate cancer cells.

Transurethral resection relieves the blockage of urinary flow caused by cancer of the prostate gland. This procedure often is performed to relieve symptoms of urinary obstruction caused by the tumor. Chemotherapy is used to treat prostate cancer if it returns after other treatment. For men who have less aggressive tumors, are older than seventy years of age, or have coexisting illnesses, many physicians will use a watch-and-wait approach before suggesting active treatment.

PROSTATE CANCER SCREENING MAY NOT REDUCE MORTALITY

Recent research revealed that the benefits of prostate cancer screening using PSA testing or digital rectal examination (DRE) may not include reducing the numbers of deaths from prostate cancer. Investigators analyzed data from 1,425 men diagnosed with prostate cancer between 1991 and 1995, identified from among more than seventy thousand patients who received care at one of ten Veteran's Administration medical centers in New England. They found that screening with PSA and DRE, either alone or in combination, did not reduce all-cause or cause-specific mortality. The researchers observed that "the PSA test isn't perfect, and that screening may lead to possible harm as well as potential benefit. The benefits include the potential for improved survival in some men. The harms include possible treatment-related side effects, including incontinence and impotence, for therapies that may be unnecessary or ineffective" (John Concato et al, "The Effectiveness of Screening for Prostate Cancer," Archives of Internal Medicine, vol. 166, no. 1, January 9, 2006).

RESPIRATORY DISEASES AND LUNG HEALTH

The American Lung Association (ALA) estimates that more than thirty-five million people suffer from some form of chronic respiratory disease (http://www.lungusa.org/atf/cf/%7B7A8D42C2-FCCA-4604-8ADE-7F5D5E762256%7D/ALA%20RAN%2005-06.PDF). In 2003, 126,382 people died from chronic lower respiratory diseases. (See Table 5.4.)

The ALA reports that each year about 349,000 Americans die of lung disease, making it the number-three killer, responsible for one in seven deaths. Death rates from chronic lower respiratory disease have increased sharply; in 1980 the age-adjusted death rate was 28.3 deaths per one hundred thousand resident population; by 2002 the rate had climbed to 43.5 per one hundred thousand. (See Table 5.8.)

The lungs are especially vulnerable to airborne particles, such as viruses, bacteria, tobacco smoke, pollen, fungi, and air pollution. Workers exposed to certain airborne hazards—cotton fibers, asbestos, and coal, metal, and silica dust—also can develop serious lung diseases. Pneumoconiosis is the general term for occupationally induced lung diseases.

Children are especially sensitive to respiratory problems. According to the ALA, acute respiratory diseases account for more than one-half of all school absenteeism.

Asthma

According to the CDC National Center for Environmental Health, in 2003 an estimated 29.8 million Americans had been diagnosed with asthma at some time in their lives, and eleven million had experienced an asthma attack in the previous year (http://www.cdc.gov/asthma/aag05.htm). Figure 5.21 shows the prevalence rates of adults by state. Asthma is the most common chronic illness among children; in 2003 about nine million children younger than eighteen years of age had asthma. (See Figure 5.22.)

People with asthma experience acute attacks of wheezing and shortness of breath. This difficulty in breathing is caused by a sudden narrowing of the bronchial tubes. Usually it is not life threatening, but asthma often limits activities and can be extremely serious for the very young and the very old.

The incidence of asthma has increased dramatically over the last twenty-five years in the United States and other industrialized nations as a result of lifestyle changes and living conditions in modern society. Exposure to air pollutants including tobacco smoke, ozone, and diesel exhaust may be contributing to this increased incidence. Indoor exposures to allergens also may contribute to the increase in asthma, because many indoor environments have been made more air tight to improve energy efficiency. Other factors implicated in the rise in asthma include the increased incidence of obesity, decreased physical activity, change in diet, decreased exposure to microbes during early life, and increased viral respiratory

infections such as those contracted by children in day care settings. Although children appear to be the population most at risk, new cases are also occurring in adults, particularly older adults.

RACIAL, AGE, AND GENDER DISPARITIES

According to the CDC's NHIS, African-Americans have higher rates of asthma and asthma-related problems than any other racial group in the United States; compared with white Americans, they are almost three times more likely to be hospitalized for asthma, five times more likely to seek care for asthma at an emergency room, and three times as likely to die from asthma. During the first half of 2005 the asthma prevalence rates continued to be the highest among African-Americans under age fifteen (13.2%). (See Figure 5.23.).

Asthma was more prevalent in all children younger than age fifteen, and more boys were more likely to have asthma than girls. However, in all other age groups, the prevalence was higher among females than among males. (See Figure 5.24.)

The CDC reports in Asthma Prevalence, Health Care Use and Mortality, 2002 (http://www.cdc.gov/nchs/products/pubs/pubd/hestats/asthma/asthma.htm) that deaths from asthma are on the decline; the number of deaths from asthma in 2002 (4,261) has decreased from 4,487 in 2000. Asthma deaths in children are rare. In 2002, 187 children up to age seventeen died from asthma, or 0.3 deaths per one hundred thousand children, compared with 1.9 deaths per one hundred thousand adults age eighteen and older. Non-Hispanic African-Americans were the most likely to die from asthma and had an asthma death rate more than 200% higher than non-Hispanic whites and 160% higher than Hispanics. Females had an asthma death rate about 40% higher than males. (See Figure 5.25.)

CAUSES OF ASTHMA ATTACKS

Although the specific cause of asthma is not known, the disease appears to be associated with allergic reactions, heredity, and environment. Many environmental factors can trigger an asthma attack in susceptible individuals. Although indoor and outdoor pollution do not cause the disease, pollutants such as ozone, sulfur dioxide, nitrogen dioxide, and tobacco smoke can trigger an episode of asthma. Allergens such as pollen and dust mites also can provoke asthma attacks.

MANY ASTHMATICS DO NOT KNOW HOW TO MANAGE THEIR DISEASE

Investigators at the Boston University School of Medicine and their colleagues examined whether patients hospitalized for severe asthma knew how to manage their disease—how and when to take prescribed medication and correct use of metered dose inhalers. They found that many patients lacked the skill to properly manage their disease. The investigators did, however, observe that with thorough education, patients can readily learn and retain instructions about their asthma medication regimens and effective use of inhalers. The investigators concluded that comprehension of asthma education must be confirmed, and they exhorted educators to request that patients demonstrate mastery of inhaler use to verify their understanding (Michael K. Paasche-Orlow et al, "Tailored Education May Reduce Health Literacy Disparities in Asthma Self-Management," American Journal of Respiratory and Critical Care Medicine, vol. 172, no. 8, October 15, 2005).

Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary diseases (COPD; also referred to as chronic lower respiratory diseases), a category that includes emphysema and chronic bronchitis, are slowly progressive diseases that cause obstruction of airflow. COPD is the fourth-leading cause of death in the United States and, according to the ALA, it will be the fifth-ranked cause of disability by 2020. In 2003 more than 120,000 people died of chronic obstructive pulmonary diseases, including emphysema and chronic bronchitis. The CDC's 2004 NHIS confirmed that poverty is associated with respiratory diseases—adults in poor families had higher percentages of asthma, chronic bronchitis, and emphysema.

CHRONIC BRONCHITIS

Bronchitis is an inflammation of the lining of the bronchi, tubes that connect the trachea (windpipe) to the lungs. When the bronchi are inflamed and infected, less air is able to flow to and from the lungs, and mucus forms and is coughed up. Acute bronchitis is usually brief in duration and follows the flu or a cold. Chronic bronchitis, however, lingers for months or even years and is characterized by a persistent mucus-producing cough. It is a long-term disease characterized by breathlessness and wheezing.

The 2004 NHIS estimated that more than nine million Americans had been diagnosed with chronic bronchitis. (See Table 5.9.) In all age, sex, and race categories, people who smoke cigarettes are far more likely to develop chronic bronchitis than nonsmokers. Workers whose jobs involve inhaling large amounts of dust and irritating fumes are also more likely to get the disease. When air pollution becomes excessive, symptoms intensify.

Antibiotics and bronchodilator drugs are useful treatments, but even more important is the need to eliminate the sources of respiratory irritation. This could mean quitting smoking or avoiding polluted air, fumes, and dust. Chronic bronchitis is often the forerunner of emphysema.

EMPHYSEMA

Emphysema is a severe disease of the lungs that usually develops gradually. The air sacs on the walls of the lungs slowly lose their elasticity, and stale air becomes trapped in the lungs, which become overly inflated. This interferes with the normal exchange of oxygen and carbon dioxide. People with emphysema often feel as if they are drowning in a sea of air. In its late stage, emphysema also affects the heart, because the flow of blood from the lungs is disrupted by changes caused by emphysema. The heart has to pump harder to compensate for the disease and may become enlarged. Death often results from heart failure.

The 2004 NHIS found that more than 3.5 million Americans had been diagnosed with emphysema. Of these, almost 1.9 million were males and 1.7 million were females. (See Table 5.9.)

DIABETES

Diabetes is a disease that affects the body's use of food, causing levels of blood glucose (sugar in the blood) to become too high. Normally, the body converts sugars, starches, and proteins into a form of sugar called glucose. The blood then carries glucose to all cells throughout the body. In the cells, with the help of the hormone insulin, the glucose is either converted into energy for use immediately or stored for the future. Beta cells of the pancreas, a small organ located behind the stomach, manufacture insulin. The process of turning glucose is important because the cose for every function.

In diabetes the body can convert food to glucose, but there is a problem with insulin. In one type of diabetes (type 1) the pancreas does not manufacture enough insulin, and in another type (type 2) the body has insulin but cannot use the insulin effectively (called insulin resistance). When insulin is either absent or ineffective, glucose cannot get into the cells to be used for energy. Instead, the unused glucose builds up in the bloodstream and circulates through the kidneys. If a person's blood glucose level becomes high enough, the excess glucose "spills" over into the urine, causing frequent urination. This, in turn, leads to an increased feeling of thirst as the body tries to compensate for the fluid lost through urination.

Because diabetes deprives body cells of the glucose needed to function properly, several complications can develop to threaten the lives of diabetics further. The healing process of the body is slowed or impaired, and the risk of infection increases. Complications of diabetes include: higher risk and rates of heart disease; circulatory problems, especially in the legs, which often are severe enough to require surgery or even amputation; diabetic retinopathy, a condition that can cause blindness; kidney disease that may require dialysis; dental problems; and problems with pregnancy. Close attention to preventive health care such as regular eye, dental, and foot examinations and tight control of blood sugar levels have been shown to prevent some of the consequences of diabetes.

According to the NIDDK, more than 80% of people with type 2 diabetes are overweight, and in persons prone to type 2 diabetes, becoming overweight can trigger onset of the disease. It is not known precisely how overweight contributes to causation of this disease. One hypothesis is that being overweight causes cells to change, making them less effective at using sugar from the blood. This then stresses the cells that produce insulin, causing them gradually to fail. Maintaining a healthy weight and keeping physically fit can usually prevent or delay the onset of type 2 diabetes.

The relatively recent rise in type 2 diabetes in the United States is in part attributed to rising obesity among adults as well as overweight among children and adolescents. A CDC study (http://www.cdc.gov/mmwr/PDF/wk/mm5345.pdf) found that 54.8% of diabetics over age nineteen were obese between 1999 and 2002 compared with 45.7% in the same age group between 1988 and 1994. When the category was expanded to include diabetics who were obese or overweight, the percentage escalated to 85.2% in 1999–2002 compared with 78.5% in the earlier period.

Types of Diabetes

Non-insulin-dependent diabetes (type 2) is most often seen in adults and is the most common type of diabetes in the United States. In this type the pancreas produces insulin, but it is not used effectively and the body resists responding to it.

The individuals most at risk for type 2 diabetes are usually overweight, are older than age forty, and have a family history of diabetes. According to the American Diabetes Association (http://www.diabetes.org/), patients with type 2 diabetes represent about 90-95% of patients with diabetes. Type 1 accounts for only about 5-10% of diabetes cases.

To determine whether someone has prediabetes or diabetes, a fasting plasma glucose (FPG) test or an oral glucose tolerance test (OGTT) is done in the doctor's office. A fasting blood glucose level between 100 and 125 mg/dl signals prediabetes, and a fasting blood glucose level of 126 mg/dl or higher signals diabetes. With the OGTT test, a patient fasts overnight, then drinks a solution rich in glucose. The patient's blood glucose level is then measured at one-hour intervals, commonly over two to five hours, to determine the rate at which the glucose is consumed. A diagnosis of prediabetes is made when the two-hour blood glucose level is between 140 and 199 mg/dl, and diabetes is diagnosed when the level is 200 mg/dl or higher.

Warning Signs of Diabetes

The symptoms of type 1 diabetes usually occur suddenly. These include excessive thirst, frequent urination, weight loss, weakness and fatigue, nausea and vomiting, and irritability. The symptoms of type 2 diabetes generally appear gradually. These may include any of the symptoms seen in type 1 diabetes, plus recurring infections that are slow to heal, drowsiness, blurred vision, numbness in the hands or feet, and itching.

Prevalence of Diabetes

The NHIS found that from 1997 through June 2005 there was an increase in diagnosed diabetes among U.S. adults. In 2005 more than 7% of the U.S adult population had been diagnosed with diabetes by a physician or other health professional. (See Figure 5.26.) Worse still, these numbers may significantly underestimate the true prevalence of diabetes in the United States in view of the findings of the National Health and Nutrition Examination Survey (conducted by the National Center for Health Statistics, a division of the CDC) that showed sizeable numbers of adults have undiagnosed diabetes.

The prevalence of diabetes increases with age among men and women, with the highest rates among older adults—persons age sixty-five and older. In all age categories the prevalence of diagnosed diabetes was higher in men than women. (See Figure 5.27.) The CDC also reports (http://www.cdc.gov/nchs/data/nhis/earlyrelease/200512_14.pdf) that the prevalence of diagnosed diabetes was higher among non-Hispanic African-Americans (10.9%) and Hispanic persons (9.2%) than among non-Hispanic whites (6.3%).

Causes of Diabetes

The causes of both type 1 and type 2 diabetes are unknown, but a family history of diabetes increases the risk for both types, strongly suggesting a genetic component in the genesis of the disease. Some scientists believe that a flaw in the body's immune system may be a factor in type 1 diabetes. Other researchers believe that physical inactivity and the resulting poor cardiovascular fitness is a risk factor for developing diabetes.

In type 2 diabetes heredity may be a factor, but because the pancreas continues to produce insulin, the disease is considered more of a problem of insulin resistance, in which the body is not using the hormone efficiently. In people prone to type 2 diabetes, being overweight can set off the disease because excess fat prevents insulin from working correctly. Maintaining a healthy weight and keeping physically fit usually can prevent type 2 diabetes. To date, type 1 diabetes cannot be prevented.

Inhaled Insulin Is Newest Diabetes Treatment

On January 27, 2005, the FDA approved Exubera, the first short-acting insulin via an inhaler. Although use of rapid-acting inhaled insulin will not replace the need to occasionally inject the hormone, it offers many adults with type 2 diabetes an alternative to the frequent insulin injections necessary to control their blood sugar. Researchers and clinicians are optimistic that Exubera will encourage diabetics who are reluctant to inject themselves with insulin to take the insulin they need. The American Diabetes Association estimates that 15% of diabetics do not take insulin as they should. As of 2006 other alternatives to injected insulin such as mouth sprays and insulin patches were currently under development.

"Diabesity" and "Double Diabetes"

Recognition of obesity-dependent diabetes prompted scientists and physicians to coin a new term to describe this condition—diabesity. The term was first used in the 1990s, and it has gained widespread acceptance. Although diabesity is attributed to the same causes as type 2 diabetes—insulin resistance and pancreatic cell dysfunction—researchers are beginning to link the inflammation associated with obesity to the development of diabetes and cardiovascular disease.

Pediatric endocrinologist Francine R. Kaufman M.D., who served as president of the American Diabetes Association, contends that the diabesity epidemic "imperils human existence as we now know it" in Diabesity: The Obesity-Diabetes Epidemic That Threatens America—And What We Must Do to Stop It (New York: Bantam, 2005) and observes that more than one-third of American children born in 2000 will develop diabetes in their lifetime. Dr. Kaufman warns that unless drastic measures are taken, by 2020 there will be a 72% increase in the number of diabetics in America.

Another recent phenomenon is patients diagnosed with both type 1 and type 2 diabetes simultaneously. Dubbed "double diabetes," it has been reported in children and adults. Among children, it often results when children with type 1 diabetes who rely on insulin injections to control their diabetes gain weight and develop the insulin resistance that characterizes type 2 diabetes. Adults who have been diagnosed with type 2 diabetes but fail to respond to treatment have been found to also suffer from the type 1, the insulin-dependent form of the disease.

Although there are no reliable statistics about the prevalence of double diabetes, in a July 19, 2005, interview Dr. Dorothy Becker, a pediatric endocrinologist and leading double-diabetes researcher at Children's Hospital of Pittsburgh, estimated that 25% of children with type 1 diabetes who are overweight also have symptoms of type 2 diabetes. Dr. Becker theorizes that overweight people require more insulin to process glucose regardless of whether they are insulin-resistant. It may be that obesity overworks the pancreas until it wears out. It also is possible that obesity triggers or hastens the autoimmune destruction, which implies that individuals genetically predisposed to type 1 diabetes might not develop the disease if they maintained a healthy weight (Lauran Neergaard, "'Double Diabetes' Harder to Detect, Treat," Associated Press, July 19, 2005).

Deaths Resulting from Diabetes

The risk for death among people with diabetes is about twice that of their age peers without diabetes. Diabetes was the sixth-leading cause of death in the United States in 2003 and was responsible for more than seventy-four thousand deaths. (See Table 5.4.) The NIDDK asserts that diabetes is likely to be underreported as a cause of death. The institute reports that only about 35-40% of the deceased with diabetes had diabetes listed on their death certificates and just 10-15% had it listed as the underlying cause of death.

CHRONIC CONDITIONS LIMIT ACTIVITY

Besides the personal suffering associated with chronic conditions, these diseases generate an enormous financial burden on families of affected individuals and the nation in terms of medical care costs and lost productivity. The CDC reports in Health, United States, 2005 (http://www.cdc.gov/nchs/data/hus/hus05.pdf) that in 2003, 6% of adults ages eighteen to forty-four said their activity was limited compared with 21% of adults ages fifty-five to sixty-four. Chronic conditions endanger health and compromise wellness, or quality of life. Table 5.10 shows that among working-age adults, arthritis and musculoskeletal disorders were the activity-limiting chronic conditions named most frequently. Among adults ages forty-five to sixty-four, heart and circulatory problems were the second most common cause of activity limitation. Diabetes and mental illness also contributed to activity limitation. Not surprisingly, the percent of the population with activity limitation resulting from chronic conditions increases with advancing age.