Impact of hormone replacement therapy on postprandial lipoproteins and lipoprotein(a) in normolipidemic postmenopausal women.
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.
Julius
U
U
Medizinsche Kliniken, Universitätsklinikum der Technischen Universität Dresden, Germany.
Fritsch
H
H
Fritsch
W
W
Rehak
E
E
Fücker
K
K
Leonhardt
W
W
Hanefeld
M
M
D004041:Dietary Fats / Q000008:administration & dosage; D015914:Estrogen Replacement Therapy; D004966:Estrogens, Conjugated (USP) / Q000627:therapeutic use*; D005215:Fasting / Q000097:blood; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood*; D017270:Lipoprotein(a) / Q000097:blood*; D008074:Lipoproteins / Q000097:blood*; D008875:Middle Aged; D017698:Postmenopause / Q000097:blood*; D012016:Reference Values; D012307:Risk Factors
D004041:Dietary Fats; D004966:Estrogens, Conjugated (USP); D008055:Lipids; D017270:Lipoprotein(a); D008074:Lipoproteins