Sources of variation in plasma lipid and lipoprotein traits in a sample selected for health

Substantial variation in plasma lipid, lipoprotein, and apolipoprotein B levels was found in a sample of healthy white collar workers aged 23-59 years (144 women, 371 men) devoid of most clinically identifiable manifestations of cardiovascular disease or major biochemical anomalies and for whom data were gathered in Montreal, Canada, in 1987. The nature of this variability was examined for each gender by means of a stepwise linear regression analysis using indices of biologic variation and behavioral traits. In women, age, height, and weight together accounted for approximately 10% and uric acid for another 7-10% of total cholesterol, low density lipoprotein (LDL) cholesterol, and apolipoprotein B level variation. In men, age alone accounted for 13-16% of the total variation in these traits while uric acid contributed only 3%. The additional contribution of behavioral traits was found to be at least double that associated with the indices of biologic variation for measures of very low density lipoprotein (VLDL) and high density lipoprotein (HDL) cholesterol in women and HDL cholesterol in men. After taking all of the above into account, genetic variation determined by the three common apo E alleles explained an additional 6% of LDL cholesterol variation in women and 3.5% in men. These results emphasize the range of variability in lipid, lipoprotein, and apolipoprotein values in healthy individuals as well as important gender differences in the contribution of biologic, behavioral, and genetic factors in this variability.