INCREASED ACTIVITY OF LECITHIN-CHOLESTEROL ACYLTRANSFERASE DURING SHORT-TERM ORAL ESTROGEN-PROGESTIN REPLACEMENT THERAPY IN A GROUP OF POSTMENOPAUSAL WOMEN

The aim of the study was to assess the short-term effect of estrogen-p rogestin therapy on the plasma level of lecithin: cholesterol acyltran sferase ([LCAT] EC 2.3.1.43), a key enzyme in the cholesterol reverse- transport process. The trial included 21 women with at least 6 months of menopause, which was confirmed by anamnesis, physical evaluation, a nd follicle-stimulating hormone (FSH) determination. Women receiving p harmacological treatment or who had any kind of endocrine disorder wer e excluded. In addition, we evaluated and confirmed normal Papanicolao u and mammography tests in all 21 women included in the trial. They re ceived conjugated equine estrogen 0.625 mg daily, plus cyclic medroxyp rogesterone acetate (5 mg daily) for 12 days each month. Plasma levels of LCAT, cholesterol, low-density lipoprotein cholesterol (LDL-C), hi gh-density lipoprotein cholesterol (HDL-C), triglycerides, apoB, and a poAl were evaluated before and after 1 and 3 months of therapy. Prethe rapy and posttherapy results were analyzed statistically by Wilcoxon's rank-sum test for paired samples. No significant changes were observe d either for body mass index or for blood pressure. A significant incr ease in plasma LCAT activity was found at the first and third month po sttherapy (P < .005). In addition, after 3 months of therapy, HDL-C si gnificantly increased (P < .005), in contrast to the significant decre ase detected in total cholesterol (P < .025), LDL-C (P < .005), choles terol to HDL-C and LDL-C/HDL-C ratios (P < .005). Triglyceride levels did not show significant modification. In conclusion, our results indi cate that short-term estrogen-progestin therapy produces a significant increase in plasma LCAT activity, as well as beneficial changes in th e lipid profile, in postmenopausal women. Copyright (C) 1998 by W.B. S aunders Company.