Abstract

PIP: (HDL) High density liporotein levels are known to be higher in women than in men and to increase with estrogen use. To assess the effects of estrogens on HDL subspecies, analytic ultracentrifuge measurements of HDL were compared in 11 menopausal estrogen users and 16 controls. The difference in mean schlieren patterns between the groups showed a significantly higher level of HDL with flotation rate 1.5 (predominantly HDL2) in the users. This was similar to the difference in HDL seen between nonusers of hormones and age-matched males. A previous study had shown that users of combination (OCs) oral contraceptives had increased levels of HDL, suggesting that the estrogen effect on HDL is altered by the presence of added progestin. The progestin effect was studied here in more detail in 2 women with type S hyperlipoproteinemia treated with norethindrone acetate. Reduction in serum triglyceride was accompanied by a reduction in HDL, predominantly in the less dense species (HDL2). Among groups of OC and noncontraceptive estrogen and progestin users whose HDL-cholesterol levels have been reported recently, there was a direct correlation (r = 0.86, p .001) between mean HLD cholesterol and triglyceride levels. Endogenous hormonal influences on HDL were assessed by serum hormone and lipoprotein measurements at weekly intervals during 2 consecutive menstrual cycles in 4 healthy females. An increase in HDL of highest flotation rate was seen, which corresponded with the time of ovulation, raising the posibility of pituitary as well as gonadal hormone effects on HDL.