Abstract
AbstractThe effects of continuously administering both conjugated equine estrogens (CEE) and micronized progesterone (MP) on the concentration, composition, production and catabolism of very low density (VLDL) and low density lipoproteins (LDL) have not previously been reported. The mechanism of the hormonally induced reductions of plasma LDL cholesterol of Sf 0–20 (mean 16%, P < 0.005) and LDL apoB (mean 6%, P < 0.025) were investigated by studying the kinetics of VLDL and LDL apolipoprotein (apo) B turnover after injecting autologous 131I-labeled VLDL and 125I-labeled LDL into each of the 6 moderately hypercholesterolemic postmenopausal subjects under control conditions and again in the fourth week of a 7-week course of therapy (0.625 mg/d of CEE + 200 mg/d of MP). The combined hormones significantly lowered plasma LDL apoB by increasing the mean fractional catabolic rate of LDL apoB by 20% (0.32 vs. 0.27 pools/d, P < 0.03). Treatment also induced a significant increase in IDL production (6.3 vs. 3.7 mg/kg/d, P = 0.028). However, this did not result in an increase in LDL production because of an increase in IDL apoB direct catabolism (mean 102%, P = 0.033). VLDL kinetic parameters were unchanged and the concentrations of plasma total triglycerides (TG), VLDL-TG, VLDL-apoB did not rise as often seen with estrogen alone. Plasma HDL-cholesterol rose significantly (P < 0.02). Our major conclusion is that increased fractional catabolism of LDL underlies the LDL-lowering effect of the combined hormones. —Wolfe, B. M., P. H. R. Barrett, L. Laurier, and M. W. Huff. Effects of continuous conjugated estrogen and micronized progesterone therapy upon lipoprotein metabolism in postmenopausal women. J. Lipid Res. 2000. 41: 368–375.
Highlights
The effects of continuously administering both conjugated equine estrogens (CEE) and micronized progesterone (MP) on the concentration, composition, production and catabolism of very low density (VLDL) and low density lipoproteins (LDL) have not previously been reported
During weeks 3 to 6 of the administration of CEEcont/ MPcont, there were significant decreases of 8 Ϯ 2% in fasting plasma total cholesterol (6.05 Ϯ 0.27 vs. 6.57 Ϯ 0.19 mmol/L, P Ͻ 0.01, Table 1) and 16 Ϯ 2% in the concentration of cholesterol of LDL of Sf 0–20 (4.13 Ϯ 0.21 vs. 4.86 Ϯ 0.21 mmol/L, P Ͻ 0.005)3, whereas HDL cholesterol rose by 30 Ϯ 9% (P Ͻ 0.025, Table 1)
Data obtained at time of the turnover studies comparing control versus treatment indicated that CEEcont/MPcont reduced the mean plasma concentration of cholesterol transported in LDL of Sf 0–12 by 13 Ϯ 3% (3.70 Ϯ 0.24 vs. 4.27 Ϯ 0.19 mmol/L, P Ͻ 0.005) and increased mean HDL cholesterol by 30 Ϯ 8% (1.32 Ϯ 0.10 vs. 1.01 Ϯ 0.09 mmol/L, P Ͻ 0.01, Table 2)
Summary
During weeks 3 to 6 of the administration of CEEcont/ MPcont, there were significant decreases of 8 Ϯ 2% in fasting plasma total cholesterol (6.05 Ϯ 0.27 vs. 6.57 Ϯ 0.19 mmol/L, P Ͻ 0.01, Table 1) and 16 Ϯ 2% in the concentration of cholesterol of LDL of Sf 0–20 (4.13 Ϯ 0.21 vs. 4.86 Ϯ 0.21 mmol/L, P Ͻ 0.005), whereas HDL cholesterol rose by 30 Ϯ 9% (P Ͻ 0.025, Table 1). The mean values tended to decline during treatment for each of plasma total triglycerides (1.72 Ϯ 0.36 vs 2.20 Ϯ 0.34 mmol/L), VLDL triglycerides (0.75 Ϯ 0.17 vs 0.96 Ϯ 0.20 mmol/L, Table 2), IDL triglycerides (0.52 Ϯ 0.16 vs 0.69 Ϯ 0.10 mmol/L), and LDL triglycerides (0.28 Ϯ 0.02 vs 0.36 Ϯ 0.056 mmol/L), the changes were not
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
