Impact of hormone replacement therapy on postprandial lipoproteins and lipoprotein(a) in normolipidemic postmenopausal women

• Published in: The Clinical investigator Vol. 72; no. 7; p. 502
• Main Authors: Julius, U, Fritsch, H, Fritsch, W, Rehak, E, Fücker, K, Leonhardt, W, Hanefeld, M
• Format: Journal Article
• Language: English
• Published: Germany 01.07.1994
• Subjects: Dietary Fats - administration & dosage; Estrogen Replacement Therapy; Estrogens, Conjugated (USP) - therapeutic use; Fasting - blood; Female; Humans; Lipids - blood; Lipoprotein(a) - blood; Lipoproteins - blood; Middle Aged; Postmenopause - blood; Reference Values; Risk Factors
• ISSN: 0941-0198
• DOI: 10.1007/BF00207478

In 43 normolipidemic postmenopausal women we studied fasting and postprandial (oral fat load with 50 g fat per square meter; blood sampling for 5 h) lipoprotein components and lipoprotein(a) levels before and with the administration of conjugated equine estrogens opposed by medrogestone (on days 11-21). Data was compared intraindividually; the second testing was performed during the last 5 days of the combined estrogen/progestogen phase of the third cycle. Fasting low-density lipoprotein (LDL) and total cholesterol concentrations decreased significantly; high-density lipoprotein (HDL) cholesterol, including subfractions HDL2 and HDL3, was not changed. Fasting triglyceride concentrations increased. All lipoprotein fractions measured showed a postprandial elevation with the exception of chylomicron cholesterol concentrations. There was a significant effect of hormone replacement therapy on the postprandial course of total cholesterol (decrease; P < 0.001), VLDL cholesterol (increase; P = 0.025), and the triglyceride proportion in the LDL plus HDL fraction (increase; P < 0.001). With hormone replacement therapy the postprandial curve of total triglycerides was increased only 1 h after the fat load while chylomicron triglyceride concentrations were lowered after 5 h. VLDL triglycerides were not influenced. In all patients with lipoprotein(a) levels above 10 mg/dl, this parameter decreased (about 25%). Although increasing fasting triglyceride concentrations, hormone replacement therapy does not bring about an exaggerated postprandial increase in triglycerides. Postprandial chylomicron clearance is evidently promoted. Hormone replacement therapy leads to a small increase in triglycerides in the LDL plus HDL fraction by inhibiting hepatic lipase activity. Moreover, the decrease in lipoprotein(a) levels may contribute to the antiatherosclerotic effect.