Heart Disease Risk Begins With Middle-Age Risk Factors

Reed Miller

January 26, 2012

January 25, 2012 (Dallas, Texas) — A meta-analysis of 18 studies confirms that differences in risk-factor burdens in middle age translate into significant differences in lifetime cardiovascular disease risk [1].

"The current paradigm when we're thinking of prevention is to assess risk over the next 10 years using something like the Framingham risk score . . . and that's supposed to guide decision making," senior author Dr Donald Lloyd-Jones (Northwestern University, Chicago, IL) told heartwire . "That's a perfectly valid approach, but that's an incomplete way to represent risk to our patients."

The new results from the Cardiovascular Lifetime Risk Pooling Project, published in the January 26, 2012 issue of the New England Journal of Medicine, show that risk in people in their 40s or 50s with one or two risk factors such as hypertension or high cholesterol ramps up sharply over their lifetime. "So there's a disconnect between the short-term risk information that we routinely calculate and what we know, especially with this paper, are long-term risks that are dramatically higher.

"This isn't necessarily news, but this is a new way to look at it that I hope will grab people's attention more," he said. "If I can tell you that, sure your 10-year risk may be low, but based on your profile right now, your lifetime risk might be 50% or more of having a major heart attack or stroke before you die. . . . I hope that's a little more of a motivating message."

The study analyzed 18 cohort studies with 257 384 patients, including black and white men and women across a 50-year range of birth cohorts. The studies measured important cardiovascular risk factors at ages 45, 55, 65, and 75. The risk factors measured include smoking, cholesterol levels, diabetes, and blood pressure.

Calculation of lifetime risks of cardiovascular events shows that the presence of even one risk factor in middle age can dramatically increase one's lifetime risk of cardiovascular disease compared with no risk factors, and the risk goes up with each additional risk factor.

Across the whole meta-analysis, participants with no risk factors at age 55 (total cholesterol level: <180 mg/dL; blood pressure: <120 mm Hg systolic and 80 mm Hg diastolic; nonsmoking; nondiabetic) had drastically better odds of avoiding death from cardiovascular disease through the age of 80 than participants with two or more major risk factors (4.7% vs 29.6% among men and 6.4% vs 20.5% among women).

People with an optimal risk-factor profile also had lower lifetime risks of fatal coronary heart disease or nonfatal MI (3.6% vs 37.5% among men, <1% vs 18.3% among women) and fatal or nonfatal stroke (2.3% vs 8.3% among men, 5.3% vs 10.7% among women), compared with those with two or more risk factors.

Similar Risks Across Race

The lifetime risk of death from cardiovascular disease and coronary heart disease or of nonfatal MI were generally about twice as high among men than among women, but the lifetime risks of fatal and nonfatal stroke were similar for men and women.

Also, the trends shown in the study were similar for both white and black people and did not change across the diverse birth-year cohorts. "[We saw] remarkably similar results for whites and blacks in the same risk-factor categories, but there's a back story there that is a bit nuanced and is, unfortunately, bad news," he said. Black people have, on average, a greater burden of cardiovascular risk factors than white people, but black people, especially men, are at higher risk to die at younger ages from other causes and less likely to live out their "cardiovascular destiny." "So, at the end of the day, we found that the lifetime risks for whites and blacks are remarkably similar, but they arrive at those rates for somewhat different reasons. And it's important to say that it's not 'African Americaness' that's creating that situation. It's largely socioeconomic factors."

Lloyd-Jones added that the large studies of Hispanic patients do not have enough follow-up yet to provide robust lifetime-risk data, but he hopes that data will be available eventually. He expects long-term cardiovascular risk data on Asian Americans will be available soon.

Now Is the Time to Address Risk Factors

"If we can get our young adults living healthier lifestyles and more of them into middle age with optimum [risk-factor] levels, that would be fabulous news," Lloyd-Jones said. "But if you are middle-aged and you do have a risk factor or two or more, it's really time to address those. You must get [in touch] with your doctor, understand your numbers, and understand where your risk is coming from. It's almost certainly going to require help to control those [risk factors], but just as important is partnering lifestyle changes to get control of those things too. . . . It's a critically important partnership. . . . You can't put the horse completely back in the barn, but you can do a lot to mitigate those risks if you get serious about it."

Commenting on the study, epidemiologist Dr Aaron Folsum (University of Minnesota, Minneapolis) told heartwire ,"The data suggest that the US could largely eliminate coronary heart disease if, through lifestyle, we can enable adults to avoid risk factors in the first place. Coronary heart disease is a preventable disease. We need to be more aggressive at fostering healthy lifestyles in young people. This paper indicates targeting young people should pay off in the long run, not just in less CHD, but, by extrapolation, also in reduced health costs."

This study was supported by grants from the National Heart, Lung, and Blood Institute. Disclosure forms provided by the authors are available with the full text of this article.