Objective: To describe the risk factors associated with cardiovascular mortality in the African American (AA) and Hispanic populations in Los Angeles County in an effort to define causes for the excess mortality seen in AAs.
Methods: This was a longitudinal analysis of all-cause, cardiovascular, and cerebrovascular mortality in a large, prospective multiethnic cohort of individuals aged 45-74 years. Death rates between AA and Hispanic men and women during the six-year period from 1993 to 1998 due to hypertension, cardiomyopathy, acute myocardial infarction (AMI), ischemic heart disease, and stroke were compared.
Results: There were 1,157 deaths due to cardiovascular disease (CVD) or cerebrovascular disease among the 71,798 eligible members of the cohort included in these analyses. Age-adjusted mortality rates were two to five times higher in AAs as compared with Hispanics (e.g., 373.15 in AAs for hypertensive disease vs 50.37 in Hispanics). A history of hypertension was the most common significant risk factor for CVD; other risk factors significantly associated with CVD mortality included cigarette smoking and a past history of diabetes and stroke. Adjusting for these factors did not remove the significance of AA ethnicity as a risk factor for CVD mortality in either subjects reporting or subjects not reporting hypertension at baseline.
Conclusions: The evidence for both higher relative severity and higher incidence of hypertensive disease among AAs, and the consistency of the effect across gender, suggests that a major determinant of risk may be a gene environment interaction.