African-Americans at lower socioeconomic levels have increased risk of heart disease

African Americans at lower socioeconomic levels, particularly women and younger adults, are at greater risk of heart disease and stroke than those in higher socioeconomic positions, according to research in the Journal of the American Heart Association.

Cardiovascular disease (CVD) is the No. 1 killer of all Americans, but the burden is greater for African Americans. According to the American Heart Association 2014 Statistical Update, nearly half of all African American adults have some form of CVD, and they are twice as likely as white adults to have a first-ever stroke.

Researchers used data from the Jackson Heart Study, which enrolled 5,301 African American participants (3,360 women) aged 21 to 94 in the Jackson, Miss., area and followed them for up to 10 years. During that time, 362 new or recurrent CVD events were recorded, including heart attacks, heart disease deaths, strokes and cardiovascular procedures. Of these events, 213 were in women and 149 in men.

Researchers found that in African-Americans:

• Women in the lowest socioeconomic group had more than twice the risk of experiencing a CVD event than those in the highest group.
• Men and women 50 years and younger in the lowest socioeconomic group had more than three times higher risk of experiencing a CVD event than those in the highest group.

"Our findings underscore the need for increased awareness and education about prevention and early detection and treatment of CVD in African American women and younger adults of low socioeconomic status," said Samson Y. Gebreab, Ph.D., M.Sc., lead study author and research scientist at the National Human Genome Research Institute, Bethesda, Maryland. "This is especially true because African Americans generally have less access to health care and are less likely to undertake routine physical examination, despite their increased risk for cardiovascular disease."

Researchers used multiple measures to assess participants, including education, income, wealth and public assistance. For each measure, they divided the study population into thirds by defining low, medium and high. They also adjusted for CVD behavioral and health risk factors: smoking, alcohol use, physical activity, body mass index, type 2 diabetes, hypertension, cholesterol and triglycerides.

After adjustment, they found:

• Being an African American adult age 50 or younger or an African American woman of any age remained independent predictors of CVD.
• By itself, wealth proved to be an independent predictor of CVD in women. Those in the lowest third were 68 percent and those in the middle third were 61 percent more likely to experience a CVD event than those in the top third.

Researchers also analyzed participants' childhood socioeconomic status by asking them to recall their parents' education, home ownership and household amenities but they didn't find a link.

"The findings should be interpreted with caution given that childhood socioeconomic status is notoriously difficult to measure for a number of reasons, including recall bias, but other studies have shown that childhood socioeconomic status can have a critical impact on adult health independent of adult socioeconomic status. Our results may simply reflect a limitation of our study," Gebreab said. "However, we also think that traditional measures of childhood socioeconomic status may not accurately reflect the childhood social environments of African Americans, which is quite different from that of U.S. whites because of the history of racial discrimination and segregation. We believe that those factors should also be explored to better understand the life-course contribution to CVD risk in African Americans."

Authors say these results need to be replicated in other African American populations.