African Americans are known to have a higher rate of heart disease and stroke than whites, and a new study suggests that those excess risks emerge at a relatively young age.

Using data from a government health study, researchers found that African Americans between the ages of 35 and 44 had nearly twice the prevalence of cardiovascular disease -- a history of heart attack, heart failure or stroke -- than their white counterparts.

Extrapolating to the general U.S. population, the researchers estimate that just under 2 percent of white adults in that age group had ever been diagnosed with cardiovascular disease, versus just under 4 percent of African Americans.

The racial gap persisted among adults in their 40s and 50s, though it declined with each decade, until there was no significant difference after age 60.

Moreover, the study found, 28 percent of deaths from cardiovascular disease among black Americans struck before the age of 65, compared with 13 percent among white Americans.

The findings underscore a need for prevention efforts targeting young African Americans in particular, according to the researchers, led by Dr. Stacey Jolly of the Cleveland Clinic Medicine Institute in Ohio.

The researchers were able to account for a number of factors in cardiovascular disease risk in this study group -- including reported rates of risk factors like high blood pressure, obesity and smoking; and socioeconomic factors like education, income and access to healthcare.

With that information factored in, the links between race and cardiovascular disease among younger and middle-aged Americans weakened -- suggesting that disparities in risk factors and socioeconomics largely explain the connection.

For the general public, Jolly said, the message is that it's never too early to try to control cardiovascular risk factors by maintaining healthy lifestyle habits, with regular exercise, a balanced diet, and not smoking being prime examples.

But there are broader public health implications as well, Jolly told Reuters Health.

Younger adults have always been less likely than older ones to lack health insurance and access to regular healthcare, she noted, and studies indicate the problem is more acute among younger African Americans.

And since more general socioeconomic factors -- like education level and income -- appeared to account for some of younger African Americans' excess cardiovascular risks, public policies that address those racial gaps could ultimately affect disparities in heart health, Jolly said.

The findings are based on data from a periodic government health study of a nationally representative sample of U.S. adults. Jolly's team focused on white and African-American adults who took part in the study between 1999 and 2006. They used a separate federal database to look at national death rates from cardiovascular disease around that same time period.

During the survey, participants were asked whether a doctor had ever diagnosed them with a heart attack, stroke or heart failure.

Based on those responses, Jolly's team estimates that about 0.8 percent of white Americans between the ages of 35 and 44 had ever been diagnosed with a heart attack; that compared with 1.4 percent of African Americans.

A similar disparity was seen with stroke (roughly 1 percent, versus 1.5 percent) and heart failure (just under 0.5 percent, versus just under 1 percent).

And while the bulk of deaths from cardiovascular disease was among adults age 65 and up, younger African Americans had higher rates than their white counterparts. In the 45 to 54 age group, for example, the annual death rate from cardiovascular disease was 111 per 100,000 African Americans, and 47 per 100,000 whites.

The death rate data came from a database maintained by the Centers for Disease Control and Prevention; the researchers had no additional information to investigate the potential reasons for the racial disparities in deaths.

The higher rate of cardiovascular disease among younger African Americans would certainly play a role in their higher death rates, Jolly noted. But it's also likely that other factors, like racial gaps in medical care, could help explain the finding, she added.

Healthcare Medicine