Effects of unopposed conjugated equine estrogen on lipoprotein composition and apolipoprotein-E distribution.
Abstract: Administration of conjugated equine estrogen to 31 postmenopausal women for 3 months produced 14.6% and 9.4% decreases in low density lipoprotein cholesterol (LDL-C) and apolipoprotein-B (apoB), and 11.5%, 12.7%, and 9.6% increases in high density lipoprotein cholesterol (HDL-C), apoA-I and apoA-II, respectively. Phospholipids of HDL2 and HDL3 were increased 57.9% and 19.3%, respectively, while relatively small increases in cholesterol of the two subfractions were not significant. Compositions of LDL and HDL and its subfractions were altered substantially with estrogen treatment. The proportion of LDL triglyceride to LDL-C was increased. The phospholipid content in both the HDL2 and HDL3 subfractions (compared to cholesterol) was increased significantly (34.8% and 10.7%, respectively), while the triglyceride content was increased only in the HDL2 subfraction (43.6%). Estrogen use also caused a 9.1% reduction in total apoE levels and a redistribution of apoE to the very low density lipoprotein (VLDL) from the LDL plus HDL fraction, resulting in a significant 19.5% decrease in apoE in the LDL plus HDL fraction. Changes in apoE in the VLDL fraction were associated positively with changes in the cholesterol levels of the VLDL fraction and inversely with changes in LDL-C and apoB levels, while changes in apoE in the LDL plus HDL fraction were associated positively with changes in the levels of HDL-C. Thus, estrogen causes alterations in lipoproteins that could potentially affect their metabolism and/or function.
Publication Date: 1992-11-01 PubMed ID: 1430085DOI: 10.1210/jcem.75.5.1430085Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
- Journal Article
- Research Support
- U.S. Gov't
- P.H.S.
Summary
This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.
The research examines how administration of conjugated equine estrogen for three months affects lipoprotein composition and apolipoprotein-E distribution in postmenopausal women. Its main findings reveal significant changes in the composition of LDL (low-density lipoprotein) and HDL (high-density lipoprotein) and the distribution of apoE (apolipoprotein-E).
Methodology and Participants
- The study was conducted on 31 postmenopausal women.
- The participants were given conjugated equine estrogen treatment for a period of three months.
Effects on Lipoprotein Composition
- The treatment resulted in a 14.6% decrease in LDL-C (low density lipoprotein cholesterol) and a 9.4% decrease in apoB (apolipoprotein-B).
- The HDL-C (high density lipoprotein cholesterol), apoA-I and apoA-II levels increased by 11.5%, 12.7%, and 9.6% respectively.
- Substantial changes were observed in the composition of LDL and HDL, with a significant increase in the proportion of LDL triglyceride to LDL-C.
- Estrogen treatment also led to a significant increase in phospholipid content in both HDL subfractions, HDL2 and HDL3.
Effects on Apolipoprotein-E Distribution
- The study found an overall 9.1% reduction in total apoE (apolipoprotein-E) levels.
- There was a redistribution of apoE to the VLDL (very low density lipoprotein) from the LDL plus HDL fraction.
- This led to a significant 19.5% decrease of apoE in the LDL plus HDL fractions.
- Changes in apoE in the VLDL fraction were associated positively with changes in the cholesterol levels of the VLDL fraction and inversely with changes in LDL-C and apoB levels.
- Changes in apoE in the LDL plus HDL fraction were associated positively with changes in the levels of HDL-C.
Implications of the Study
- The study suggests that estrogen causes alterations in lipoproteins that could potentially affect their metabolism and/or function.
- The significant alterations in LDL and HDL components and shifts in apolipoprotein-E distribution could provide insights into the role of estrogen in lipid metabolism and cardiovascular health in postmenopausal women.
Cite This Article
APA
Muesing RA, Miller VT, LaRosa JC, Stoy DB, Phillips EA.
(1992).
Effects of unopposed conjugated equine estrogen on lipoprotein composition and apolipoprotein-E distribution.
J Clin Endocrinol Metab, 75(5), 1250-1254.
https://doi.org/10.1210/jcem.75.5.1430085 Publication
Researcher Affiliations
- Department of Medicine, George Washington University Medical Center, Washington, D.C. 20037.
MeSH Terms
- Adult
- Animals
- Apolipoproteins / blood
- Apolipoproteins E / blood
- Cholesterol, HDL / blood
- Cholesterol, LDL / blood
- Estrogens / pharmacology
- Female
- Horses
- Humans
- Lipoproteins / blood
- Lipoproteins / chemistry
- Middle Aged
Grant Funding
- R01-HL-34996 / NHLBI NIH HHS
Citations
This article has been cited 3 times.- Teter B. ApoE-dependent plasticity in Alzheimer's disease.. J Mol Neurosci 2004;23(3):167-79.
- Turner RS. Alzheimer's disease in man and transgenic mice: females at higher risk.. Am J Pathol 2001 Mar;158(3):797-801.
- Julius U, Fritsch H, Fritsch W, Rehak E, Fücker K, Leonhardt W, Hanefeld M. Impact of hormone replacement therapy on postprandial lipoproteins and lipoprotein(a) in normolipidemic postmenopausal women.. Clin Investig 1994 Jul;72(7):502-7.
Use Nutrition Calculator
Check if your horse's diet meets their nutrition requirements with our easy-to-use tool Check your horse's diet with our easy-to-use tool
Talk to a Nutritionist
Discuss your horse's feeding plan with our experts over a free phone consultation Discuss your horse's diet over a phone consultation
Submit Diet Evaluation
Get a customized feeding plan for your horse formulated by our equine nutritionists Get a custom feeding plan formulated by our nutritionists
