Lipoprotein, apolipoprotein, and lipolytic enzyme changes following estrogen administration in postmenopausal women

• Published in: Journal of lipid research Vol. 30; no. 12; pp. 1895 - 1906
• Main Authors: Applebaum-Bowden, D, McLean, P, Steinmetz, A, Fontana, D, Matthys, C, Warnick, G R, Cheung, M, Albers, J J, Hazzard, W R
• Format: Journal Article
• Language: English
• Published: United States Elsevier 01.12.1989
• Subjects: Aged; Apolipoproteins - blood; Apolipoproteins - drug effects; Ethinyl Estradiol - pharmacology; Female; Humans; Lipase - blood; Lipids - blood; Lipoproteins - blood; Lipoproteins - drug effects; Menopause - blood; Middle Aged; Phosphatidylcholine-Sterol O-Acyltransferase - blood
• ISSN: 0022-2275
• DOI: 10.1016/S0022-2275(20)38202-X

To test whether estrogen can modulate the cholesterolemic response to an Occidental diet, six healthy postmenopausal women were studied for 84 days while ingesting a solid food diet of constant composition high in cholesterol content (995 mg/d). In the middle of the study, estrogen (17 alpha-ethinyl estradiol, 1 microgram/kg per day) was administered orally. Ingestion of the diet for the initial 28 days did not alter lipoprotein lipid or apolipoprotein (apo) levels. However, with just 4 days of estrogen use there were significant decreases in apoE (-36%), low density lipoprotein cholesterol (-26%), and postheparin plasma hepatic triglyceride lipase activity (HTGL) (-61%), and an increase in high density lipoprotein (HDL) triglyceride (72%). These changes persisted throughout the estrogen use. The percent change in HTGL with 4 days of estrogen correlated inversely with the percent change in HDL triglyceride (rs = -0.94). After 28 days of estrogen there were also significant increases in HDL cholesterol (21%), HDL2 cholesterol (42%), apoA-I (37%), and apoA-II (9%), and a decrease in apoB (-11%). The level of apoE at this juncture correlated inversely with the level of HDL cholesterol (rs = -0.90), and the levels of HTGL and apoA-I correlated with HDL2 cholesterol (rs = -0.89 and rs = 0.89, respectively). Thus, HTGL may play a role in both the early estrogen-related changes in HDL triglyceride and apoE and the late estrogen-related changes in HDL cholesterol, apoA-I, and apoA-II.