Feb. 6, 2006 — Just more than half of men and 40% of women at age 50 in the U.S. will develop cardiovascular disease during their lifetime. But researchers say the danger is much greater for people who have multiple risk factors for heart disease by age 50.
The first-ever comprehensive lifetime risk assessment for cardiovascular disease highlights the importance of reducing risk early in life to prevent heart and vascular disease later on. Cardiovascular disease events included heart attack, angina, coronary heart disease, stroke, and claudication (peripheral arterial disease).
Reducing risk means maintaining a healthy weight, getting plenty of exercise, keeping cholesterol levels and blood pressure under control, and not smoking, says Donald M. Lloyd-Jones, MD, ScM, part of the research team that developed the lifetime risk assessment.
“Once risk factors develop it is hard to get the cat back in the bag,” he says. “If we can get people to focus more on healthy lifestyles and risk factors, we can essentially make this disease a thing of the past.”
Abolishing Future Risk
Lloyd-Jones and colleagues from Northwestern University used data from the Framingham Heart Study, which has followed thousands of people for decades, to calculate lifetime cardiovascular risk among 50-year-olds. They found that:
- The average lifetime risk of developing cardiovascular disease was around 52% for men and 39% for women.
- Lifetime risk jumped to 69% for men and 50% for women who had two or more cardiovascular risk factors by age 50.
- Lifetime risk was just 5% among men and 8% among women who had optimal risk factors for cardiovascular disease at age 50. That meant that they were not overweight, did not smoke, and did not have diabetes, high cholesterol, and high blood pressure.
These low-risk 50-year-olds tended to live into their 90s, whereas the median survival for men and women with two major cardiovascular risk factors was roughly a decade shorter.
“If you reach age 50 with all optimal risk factors, you have essentially abolished your future risk of cardiovascular disease,” Lloyd-Jones tells WebMD.
Just 3% of men and 4% of women in the analysis fell into this very low-risk category at age 50. But Lloyd-Jones says many more Americans could reach their sixth decade with almost no cardiovascular risks.
“It sounds trite, but physical activity, eating a healthy diet, and maintaining a healthy weight could make all the difference,” he says. “Yet, the number of overweight and obese individuals is skyrocketing.”
Diabetes Patients Had Highest Risk
The researchers reviewed the medical records of 3,564 men and 4,362 women who did not have any record of cardiovascular disease at age 50. The men and women were followed for several decades and all cases of heart attack, coronary heart disease, angina, stroke, claudication (pain in the legs caused by circulation problems), and death from cardiovascular disease were recorded.
When the researchers calculated the impact of modifiable risk factors such as body weight, smoking history, cholesterol levels, and blood pressure, they found that:
- Having diabetes was the single greatest risk factor for developing cardiovascular disease. Roughly 67% of men with diabetes at age 50 and 57% of women had developed cardiovascular disease by age 75.
- Smokers and nonsmokers had similar lifetime risks for cardiovascular disease, but smokers developed cardiovascular problems earlier in life and died an average of five years sooner. The researchers note that this might be due to other smoking-related causes such as lung disease and cancer.
- Being overweight or obese at age 50 was linked to “modest” increases in lifetime risk for cardiovascular disease and reduction in survival.
The study appears in the Feb. 14 issue of the American Heart Association journal Circulation.
Begin Prevention Early
Lloyd-Jones says he is hopeful that understanding their lifetime cardiovascular risk will motivate younger adults to take steps to reduce it.
Most physicians currently use 10-year risk to determine how aggressively to treat patients at risk for heart disease and stroke. But because the risk of having a heart attack, stroke, or other cardiovascular event increases with age, this measure may not be adequate for young people and middle-aged adults.
For example, a 50-year-old with high cholesterol and high blood pressure has only a 7% risk of having a heart attack or dying of coronary disease by age 60. But his lifetime risk is 10 times greater than a man of the same age with no risk factors.
“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 cardiovascular disease and shorter survival,” Lloyd-Jones says.
Boston cardiologist Jorge Plutzky, MD, says the lifetime risk assessment should help primary care doctors better convey cardiovascular risk to their younger patients.
Plutzky directs the vascular disease prevention program at Brigham and Women’s Hospital.
“Cardiologists don’t often see people with no history of cardiovascular events, like the 50-year-olds in this study,” he says. “This research may help physicians who do see these patients help them understand their risk.”