EFFECTS OF GENDER AND MENOPAUSAL STATUS ON PLASMA-LIPOPROTEIN SUBSPECIES AND PARTICLE SIZES

The risk of coronary heart disease (CHD) is lower in women than in men , but increases in women after menopause. Some of the gender, age, and menopausal-related differences in CHD risk may relate to differences in lipoprotein subspecies. We therefore examined these subspecies in t hree groups of healthy subjects: premenopausal women (W, n = 72, mean age 41.2 +/- 6.5), postmenopausal women (PMW, n = 74, 55.8 +/- 7.4), a nd men (M, n = 139, 48.8 +/- 10.7). We measured plasma levels of Lipid s, lipoprotein cholesterol, apolipoproteins A-I, A-IV: B, C-III, and E , and lipoprotein subspecies Lp A-I, Lp A-I:A-II, Lp B, Lp B:C-III, an d Lp B:E, as well as LDL and HDL particle sizes, Our data indicate tha t women have significantly higher values of HDL-C, apoA-I, apoE, and L p A-I; larger LDL and HDL particle sizes; and lower values of triglyce ride, apoB, and Lp B;C-III particles than men, with no difference in L p A-I:A-II. Post-menopausal status was associated with significantly h igher values of total cholesterol, triglyceride, VLDL-C, and LDL-C; in creased levels of apoB, C-III, and E; elevated values of Lp B, Lp B:C- III, and Lp B:E; and lower levels of HDL-C along with smaller HDL. par ticle size. Moreover, we noted a strong correlation between LDL and HD L particle size. Our data are consistent with the concepts that male g ender confers decreases in HDL subspecies due to lower Lp A-I levels; while postmenopausal status results in higher levels of all apoB-conta ining lipoproteins (Lp B, Lp IS:C-III, and Lp B:E). Tile lipoprotein a lterations associated with male gender and postmenopausal status would be expected to increase CHD risk.