Relationship of lipoproteins, apolipoproteins, triglycerides and lipid ratios to plasma total cholesterol in young adults: the CARDIA Study. Coronary Artery Risk Development in Young Adults.

Objective: To characterize the association of carrier lipoproteins, apolipoproteins, triglycerides and various lipid ratios with total cholesterol in young adults.

Design: Cross-sectional data from the baseline examination (1985-1986) of The Coronary Artery Risk Development In Young Adults (CARDIA) Study, a multicenter investigation of a biracial cohort of 4941 men and women aged 18-30 years.

Methods: Multiple linear regression models to estimate mean levels of lipids and lipoproteins for each category of total cholesterol, stratified by race and sex and adjusted for age and education level.

Results: As expected, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein B (ApoB), apolipoprotein A-1 (ApoA-1) and triglycerides increased linearly with the level of total cholesterol in all race-sex subgroups. The LDL-C/HDL-C, ApoB/ApoA-1 and LDL-C/ApoB ratio also increased with total cholesterol in all race-sex subgroups. The HDL-C/ApoA-1 ratio, indicative of cholesterol content per HDL particle, did not vary with total cholesterol except in white men, in whom it was slightly lower for those with high total cholesterol than those with low total cholesterol concentrations. White men showed higher triglyceride concentrations and lower HDL-C for any given total cholesterol strata. All these associations of lipoproteins, apolipoproteins and lipid ratios with total cholesterol were independent of body mass index, smoking status, fitness level and Keys score.

Conclusions: Young adults with low total cholesterol have lipoprotein profiles characterized by low atherogenic potential. White men with high total cholesterol levels, compared with other groups, showed a lipid profile more conductive to atherogenesis.