title: Hormone replacement therapy enhances postprandial lipid metabolism in postmenopausal women.
abstract: Postmenopausal estrogen therapy reduces cardiovascular morbidity and mortality, except in women with advanced coronary disease. This beneficial effect is partly attributed to a reduction of fasting plasma total and low-density lipoprotein cholesterol (LDL-C) and an elevation of plasma high-density lipoprotein cholesterol (HDL-C) concentrations. Since postprandial lipemia seems to play a role in the pathogenesis of coronary artery disease, we evaluated the effect of hormone replacement therapy (HRT) on postprandial lipoprotein metabolism in 14 normolipemic postmenopausal women. A vitamin A fat-loading test before and after three cycles of treatment with a sequential combination of conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA) was used to label chylomicrons and chylomicron remnants with retinyl palmitate (RP), and RP clearance was assessed over an 8-hour period postprandially. Following 3 months of HRT, fasting total cholesterol and LDL-C levels were reduced 9.8% (P = .049) and 16.5% (P = .023), respectively. Fasting HDL-C levels increased 18.9% (P = .001). Fasting triglycerides (TGs) increased, but not significantly. Postprandial integrated plasma TGs did not change significantly. The integrated RP levels in whole plasma and chylomicron (Svedberg flotation units [Sf] > 1,000) and nonchylomicron (Sf < 1,000) fractions were reduced 58% (P = .043), 78% (P = .041), and 75% (P = .001), respectively, after hormonal treatment. Enhanced clearance of chylomicrons and chylomicron remnants by HRT may contribute to the protective effect of estrogens against cardiovascular disease in normolipemic postmenopausal women.
authors.affiliation: Department of Internal Medicine C, the Menopause Clinic, Tel Aviv-Sourasky Medical Center and Sackler Faculty of Medicine, Tel-Aviv University, Israel.
authors.forename: M
authors.initials: M
authors.lastname: Weintraub
authors.forename: I
authors.initials: I
authors.lastname: Grosskopf
authors.forename: G
authors.initials: G
authors.lastname: Charach
authors.forename: N
authors.initials: N
authors.lastname: Eckstein
authors.forename: A
authors.initials: A
authors.lastname: Rubinstein
mesh_terms: D002914:Chylomicrons / Q000097:blood; D004224:Diterpenes; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007557:Israel; D050356:Lipid Metabolism; D017698:Postmenopause / Q000502:physiology*; D019518:Postprandial Period / Q000502:physiology*; D000084562:Retinyl Esters; D014280:Triglycerides / Q000097:blood; D014801:Vitamin A / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism
chemical_list: D002914:Chylomicrons; D004224:Diterpenes; D004967:Estrogens; D000084562:Retinyl Esters; D014280:Triglycerides; D014801:Vitamin A; C014794:retinol palmitate