Coronary heart disease risk factor trends in blacks between the first and second National Health and Nutrition Examination Surveys, United States, 1971-1980.

This article focuses on changes in prevalence of three of the major risk factors for coronary heart disease (CHD) among the black population aged 25 to 74 years: blood pressure, cigarette smoking, and serum cholesterol. It also examines the extent to which changes in these risk factors might explain changes in observed CHD mortality. These national estimates of risk factor levels among the black U.S. population are based on cross-sectional data from the National Health and Nutrition Examination Surveys of 1971-1975 and 1976-1980. Results of analyses show that there was a large and statistically significant decrease in the prevalence of elevated blood pressure for black adults between the two time periods; there was a large, significant decrease in the percent of black females who smoke and a smaller decrease in the proportion of black males who smoke; and there was no statistically significant change in the prevalence of elevated serum cholesterol. In addition, the percent of black adults with two or more risk factors decreased between 1971-1975 and 1976-1980. Lower levels of the three risk factors appear to explain a portion of the decline in observed CHD mortality for blacks. However, despite the encouraging lower prevalence of risk factors for blacks, more than 60% of the black adults 25 to 74 years of age still had one or more CHD risk factors in 1976-1980.