African American-white differences in lipids, lipoproteins, and apolipoproteins, by educational attainment, among middle-aged adults: the Atherosclerosis Risk in Communities Study.
Measures of socioeconomic status have been shown to be related positively to levels of high density lipoprotein (HDL) cholesterol in white men and women and negatively in African American men. However, there is little information regarding the association between educational attainment and HDL fractions or apolipoproteins. The authors examined these associations in 9,407 white and 2,664 African American men and women aged 45-64 years who participated in the Atherosclerosis Risk in Communities Study baseline survey, and they found racial differences. A positive association for HDL cholesterol, its fractions HDL2 and HDL3 cholesterol, and its associated apolipoprotein A-I was found in white men and white women, but a negative association was found in African American men, and there was no association in African American women. In whites, there was also an inverse association of low density lipoprotein (LDL) cholesterol and apolipoprotein B with educational attainment. With the exception of African American men, advanced education was associated with a more favorable cardiovascular lipid profile, which was strongest in white women. Racial differences in total cholesterol (women only), plasma triglycerides, LDL cholesterol, apolipoprotein B (women only), HDL cholesterol, HDL2 and HDL3 cholesterol, and apolipoprotein A-I were reduced at higher levels of educational attainment. Apart from triglycerides in men and HDL3 cholesterol in women, these African American-white lipid differences associated with educational attainment remained statistically significant after multivariable adjustment for lifestyle factors. Lipoprotein(a) showed no association with educational attainment. These findings confirm African American-white differences in lipids, lipoproteins, and apolipoproteins across levels of educational attainment that were not explained by conventional nondietary lifestyle variables. Understanding these differences associated with educational attainment will assist in identifying measures aimed at prevention of cardiovascular disease.