DIFFERENCES IN APOLIPOPROTEINS AND LOW-DENSITY-LIPOPROTEIN SUBFRACTIONS IN POSTMENOPAUSAL WOMEN ON AND OFF ESTROGEN THERAPY - RESULTS FROM THE FRAMINGHAM OFFSPRING STUDY

The use of estrogens by postmenopausal women has been associated with reduced risk of coronary artery disease (CAD) in some studies, possibly due to favorable effects of estrogens on plasma lipoproteins. In order to examine such effects, we studies 180 postmenopausal women from the Framingham Offspring Study, selected by type of menopause (natural or oophorectopic) and estrogen use. We determined fasting plasma total cholesterol, triglyceride, very-low-density lipoprotein (VLDL) cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and apolipoprotein (apo) A-I and B concentrations, as well as LDL particle size (LDL 1 to LDL 6). Apo A-I levels were significantly (P < .005) higher, and diastolic blood pressure and glucose levels were significantly (P < .05) lower in postmenopausal women taking estrogens regardless of type of menopause. HDL cholesterol levels were also higher in women taking oral estrogens, but differences were significant only for the oophorectomized group (P < .02). Total cholesterol, VLDL cholesterol, and LDL cholesterol levels were significantly lower (P < .01) in women with natural menopause who were taking estrogens than in women with natural menopause not taking this medication. No significant differences between estrogen users and nonusers were found with regard to triglyceride levels or LDL particle score, in either the natural menopause or oophorectomy groups. These data indicate that estrogen use in postmenopausal women is associated with significantly elevated plasma apo A-I levels and decreased LDL cholesterol concentrations. © 1990.