DIFFERENCES IN ERYTHROCYTE-MEMBRANE CHOLESTEROL TO PHOSPHOLIPIDS RATIO IN POSTMENOPAUSAL WOMEN WITH AND WITHOUT HORMONE REPLACEMENT

Objectives: To investigate the changes in the cholesterol:phospholipid s (C/PL) ratio of erythrocyte membrane in postmenopausal women with an d without hormone replacement therapy (HRT). Study design: A cross-sec tional study including 83 patients divided into three groups according to HRT (group 1, no HRT (n = 52); group 2, combined HRT (n = 16); and group 3, estrogen-only therapy (n = 15)). Results: The C/PL ratio was lower in group 2 with respect to group 1 and group 3 (P = 0.03). No d ifference was found in erythrocyte membrane cholesterol between the th ree groups; however, the phospholipid concentration was higher in grou p 2 with respect to the other groups (P < 0.05). In the control group, C/PL values correlated positively with plasma LDL levels (P < 0.005) and negatively with HDL levels (P < 0.005). Conclusions: From our data the addition of progestogens in HRT appears to decrease the C/PL of t he erythrocyte membrane possibly resulting in a beneficial effect on t heological properties of erythrocyte membrane. The results of our stud y thus suggest additional benefits from supplementation of progestogen s in HRT, in addition to prevention of estrogen dependent endometrial hyperplasia and adenocarcinoma. (C) 1997 Elsevier Science Ireland Ltd.