HDL biology
Continuous and cyclic HRT regimens both reshape HDL subclasses in postmenopausal women without altering CETP activity (Atherosclerosis 1997)
Original title: Responses of HDL subclasses, Lp(A-I) and Lp(A-I:A-II) levels and lipolytic enzyme activities to continuous oral estrogen-progestin and transdermal estrogen with cyclic progestin regimens in postmenopausal women
Seventy postmenopausal women received either continuous oral estradiol with norethisterone acetate (E2/NETA) or transdermal estradiol with cyclic medroxyprogesterone acetate (E2/MPA). After 12 months, the E2/NETA group showed HDL2 cholesterol falling 17% (P < 0.01) and HDL2b, HDL2a, and HDL3a falling 30%, 26%, and 15% (P < 0.001), while apoA-I fell 5% (P < 0.05). The E2/MPA group showed HDL2 and HDL3 cholesterol each falling 6% (P < 0.05), with apoA-II and LpA-I:A-II falling 8% and 5%. Postheparin hepatic lipase activity decreased only in the E2/NETA group (12%, P < 0.05). CETP activity was not affected by either hormone regimen, showing that these HRT-induced HDL changes are not associated with changes in lipolytic enzyme or CETP activity.
Original abstract
Seventy postmenopausal women took part in the study. Subjects received either continuous oral 17 beta-estradiol 2 mg/day combined with norethisterone acetate 1 mg/day (E2/NETA, Kliogest) or transdermal treatment consisting of 28 day cycles with patches delivering 17 beta-estradiol 50 micrograms/day (Estraderm) combined with cyclic medroxyprogesterone acetate 10 mg/day (E2/MPA, Provera), on days 17-28. At baseline the serum lipid and lipoprotein concentrations, composition and concentrations of high density lipoprotein (HDL) subclasses, lipoprotein (Lp)(AI) and Lp(A-I:A-II) levels were comparable in the two groups. In the E2/NETA group, after 12 months hormone replacement therapy (HRT), the HDL2 cholesterol concentration decreased by 17% (P < 0.01) and the HDL3 cholesterol remained unchanged. The concentrations of HDL2b, HDL2a and HDL3a were reduced by 30, 26 and 15%, respectively, P < 0.001, and the cholesterol:triglyceride ratio decreased significantly in all HDL subclasses. Apolipoprotein (apo) A-I concentration decreased by 5% (P < 0.05), but apo A-II, Lp(A-I) and Lp(A-I:A-II) concentrations remained unchanged. In the E2/MPA group the HDL2 and HDL3 cholesterol levels were both reduced by 6% (P < 0.05) and the HDL3a, HDL3b and HDL3c concentrations decreased by 14, 12 and 17% during the E2/MPA phase compared with baseline (P < 0.01). No major changes in the composition of HDL subclasses occurred in the E2 MPA group during treatment. The apo A-I and Lp(A-I) levels were not changed, but apo A-II and Lp(A-I:A-II) concentrations decreased by 8 and 5%, P < 0.001 and P < 0.05, respectively. At 12 months the postheparin plasma hepatic lipase (HL) activity decreased only in the E2/NETA group (by 12%, P < 0.05). The cholesteryl ester transfer protein (CETP) activity was not affected by either HRT regimen. The results of our study show that the 2 HRT regimens have multiple effects on HDL particles and HRT induced changes in HDL are not associated with changes in activities of lipolytic enzymes or CETP.
Summary written by cetpinhibition.org from the published abstract; figures as published. Page updated 19 August 2026. Methods.