February 7, 2006
Heart Disease Prevention Should Start Before Middle Age
CHICAGO—If you think you’re too young to worry about heart disease or stroke—think again. Efforts to prevent America’s No. 1 and No. 3 killers should begin long before you’re middle-aged, according to a study in Circulation: Journal of the American Heart Association.
The study, the first to estimate the overall lifetime risk of cardiovascular disease (CVD), found that more than half of men and nearly 40 percent of women in the United States will develop CVD during their lifetime.
At age 50, the average lifetime risk of developing CVD before age 95 is 52 percent for men and 39 percent for women. But the most striking finding was the high risk linked with having several major risk factors at age 50. Diabetes conferred the highest CVD risks.
“Men whose risk factors were all optimal at age 50 had a remaining lifetime risk of only 5 percent. Essentially, their risk of CVD had been abolished,” said lead author Donald M. Lloyd-Jones, MD, assistant professor of preventive medicine at Northwestern University’s Feinberg School of Medicine.
“Optimal risk factor levels included low total cholesterol, normal blood pressure, no diabetes and no smoking,” said Dr. Lloyd-Jones.
Men who had two or more risk factors had a lifetime risk of 69 percent. Findings were similar for women: Those with optimal risk factor levels at age 50 had a lifetime risk of 8 percent versus 50 percent lifetime risk for women with two or more risk factors.
The benefit of having optimal risk factor levels also was seen in overall survival. At age 50, men and women with optimal risk factor levels had a median survival of longer than 39 years, whereas those with two major risk factors had median survivals of 28 years for men and 31 years for women.
“Clearly, prevention efforts need to begin decades before age 50, since even the presence of a single major risk factor at age 50 substantially raises the lifetime risk for CVD and markedly shorter survival,” said Dr. Lloyd-Jones.
Although Dr. Lloyd-Jones and colleagues derived the risk estimates from nearly 8,000 50-year-olds, the risk profiles are applicable to younger Americans too.
“It turns out that because very few cardiovascular disease events occur in people younger than age 50, lifetime risk at age 50 is actually a reasonable approximation of risk across the entire lifespan,” Dr. Lloyd-Jones said.
According to Elizabeth G. Nabel, MD, director of the National Heart, Lung, and Blood Institute, “These new data underscore the value of prevention in the battle against heart disease. Preventing the development of risk factors like overweight, high blood pressure, high cholesterol, and diabetes at younger ages can help you live healthier much longer.”
The researchers reviewed the medical records of 3,564 men and 4,362 women participants in the National Heart, Lung, and Blood Institute’s Framingham Heart Study, all of whom were free of CVD at age 50. They then determined which men and women suffered atherosclerotic CVD problems in subsequent years, including heart attacks, coronary insufficiency, angina pectoris, strokes that result from a blocked artery, and death from coronary heart disease or other CVD ailments. They also calculated the impact of modifiable risk factors such as weight and smoking.
Results showed that the median overall survival after age 50 was 30 years for men and 36 years for women; at 75 years, 35 percent of the men and 19 percent of the women had developed CVD. In addition, the highest CVD risk occurred in people who had diabetes at age 50; 67 percent of diabetic men and 57 percent of diabetic women had CVD by age 75.
Obesity pushed the lifetime risk to 58 percent for men and 43 percent for women.
Finally, smokers and nonsmokers showed similar lifetime CVD risk, but smokers developed CVD sooner than nonsmokers and died an average of five years earlier.
“These data show us we need to start early to address cardiovascular disease and focus on risk factors early in life,” Dr. Lloyd-Jones said. “Once risk factors develop, it is hard to get the cat back in the bag. “
The National Heart, Lung, and Blood Institute funded the study.