Menopause is associated with reduced protection from postprandial lipemia

Deficiency of endogenous estrogens has been associated with a higher incide nce of coronary heart disease (CHD) in women. We investigated whether natur al menopause is associated with reduced protection from postprandial lipemi a, which represents a risk indicator of CHD. Twenty-three postmenopausal wo men (mean age, 50+/-1 [SD] years; body mass index, 24.6+/-2.8 kg/m(2)) and 21 premenopausal women matched for age and body mass index (age, 49+/-1 yea rs; body mass index, 24.1+/-2.6 kg/m(2)) underwent an oral vitamin A fat-lo ading test. Vitamin A is a marker of the metabolism of chylomicrons and chy lomicron remnants. All women were normolipidemic, were in good health, were nonsmokers, and used no medication. Postprandial lipids and vitamin A were measured at hourly intervals up to 12 hours. In postmenopausal women, plas ma total cholesterol and LDL cholesterol concentrations were significantly higher. Fasting plasma triglyceride (TG) concentrations were 1.14+/-0.57 mm ol/L in postmenopausal women and 0.88+/-0.33 mmol/L in premenopausal women (P=NS). In the postprandial phase, postmenopausal women had higher plasma T G(13.0+/-6.1 versus 9.5+/-3.3 mmol . L-1 . h(-1); P=0.024) and vitamin A (5 4.1+/-22.9 versus 35.9+/-9.6 mg . L-1 . h(-1); P=0.001) responses. To corre ct for the possible confounding effect of fasting TG, 13 postmenopausal wom en were carefully matched with 19 premenopausal women. Although fasting TG levels were identical (0.72+/-0.20 versus 0.73+/-0.21 mmol/L), differences in postprandial vitamin A (45.3+/-14.5 versus 33.0+/-7.7 mg . L-1 . h(-1); P=0.006) and incremental TG (ie, after subtraction of baseline TG) (3.2+/-1 .8 versus 2.3+/-1.0 mmol . L-1 . h(-1); P=0.023) persisted between postmeno pausal and premenopausal women. Natural menopause is associated with aggrav ated postprandial lipemia in women matched for age and body mass index. Hig her postprandial lipemia potentially explains the relation of TGs and CHD m ortality risk in postmenopausal women.