Changes in serum high density lipoproteins in women on oral contraceptive drugs.

Serum lipids, lipoproteins, and lipoprotein subfractions were measured in a group of 18 women aged 20 through 39 who were users of oral contraceptive drugs, and in 19 age-matched controls. Concentrations of the major lipid and lipoprotein classes were higher in the users, but the elevation was statistically significant only in the case of the high density lipoproteins. This increase was shown to be due to a highly significant increase (275 +/- 9 vs. 223 +/- 9 mg/100 ml, (p less than 0.005) in the denser high density lipoprotein subfraction (HDL3). Levels of the other subfraction (HDL2) were similar in users and controls. Thus, anovulatory steroids have selective effects on individual types of high density lipoproteins. Studies of such specific effects may help to further define the functional properties of the high density lipoproteins such as their apparent protective role in atherosclerosis.