Patterns of covariation of serum β-carotene and α-tocopherol in middle-aged adults: The Atherosclerosis Risk in Communities (ARIC) Study

Background and Aim: The patterns of covariation of β-carotene and α-tocopherol (vitamin E) with demographic, lifestyle - including dietary -, constitutional and biochemical factors were examined cross-sectionally in a case-control sub-sample of 323 middle-aged men and women free of symptomatic cardiovascular disease who attended the second visit (1990-92) of the Atherosclerosis Risk in Communities (ARIC) Study. Methods and Results: cases and controls were selected on the basis of maximum carotid intima-media wall thickening measured with β-mode ultrasonograms. In multiple linear regression analysis adjusting for gender, age, race, case-control status and ARIC field center, the absolute concentration of serum β-carotene was independently and negatively associated with alcohol consumption, body mass index, and serum sialic acid, and positively associated with serum total cholesterol. The lipid standarized serum β-carotene was independently related to alcohol consumption and sialic acid (negatively), and to vitamin supplement use (positively). The significant independent correlates of the absolute serum concentration of α-tocopherol were alcohol consumption (negative), vitamin supplement use, and total cholesterol (both positive). The lipid standardized α-tocopherol was negatively and independently related to alcohol consumption and the Keys score, and positively related to vitamin supplement use and dietary vitamin E. Conclusions: the absolute or lipid standardized β-carotene and α-tocopherol concentrations in this sample of middle-aged adults are associated, although modestly in the case β-carotene, with health habits and with constitutional and biochemical factors. Thus, studies of relationships of β-carotene and α-tocopherol with disease need to consider these possible covariates.