Hormone replacement therapy enhances postprandial lipid metabolism in postmenopausal women

• Published in: Metabolism, clinical and experimental clinical and experimental, 1999-09, Vol.48 (9), p.1193-1196
• Main Authors: Weintraub, Moshe, Grosskopf, Itamar, Charach, Gideon, Eckstein, Nachman, Rubinstein, Ardon
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Chylomicrons - blood; Estrogens - pharmacology; Female; Hormone Replacement Therapy; Hormones. Endocrine system; Humans; Israel; Lipid Metabolism; Medical sciences; Pharmacology. Drug treatments; Postmenopause - physiology; Postprandial Period - physiology; Triglycerides - blood; Tropical medicine; Vitamin A - analogs & derivatives; Vitamin A - blood; Vitamin A - metabolism
• ISSN: 0026-0495; 1532-8600
• DOI: 10.1016/S0026-0495(99)90137-3

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 [S f] > 1,000) and nonchylomicron (S f < 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.