Leptin concentrations in normal women following bilateral ovariectomy

To study the relationships between gonadal steroids and leptin, 20 women wi th normal cycles were investigated during the postoperative period followin g a laparotomy, Fourteen women underwent bilateral ovariectomy plus total h ysterectomy either in the mid- to late follicular phase (n = 7, group 1) or in the early to midluteal phase (n 7, group 2). The remaining six of the 2 0 women underwent cholocystectomy in the early to midfollicular phase of th e cycle and were used as controls (group 3), In all three groups, serum lep tin values decreased rapidly up to postoperative day 4, Then, leptin values increased significantly only in group 3 (P < 0.05), Leptin values before a nd after the operation showed significant positive correlations with body m ass index (BMI), oestradiol and progesterone. However, with multiple regres sion analysis, BMI was the only parameter significantly correlated with lep tin in group 3 (days 0 and 4-7), whereas in groups 1 and 2 progesterone and BMI showed independent significant correlations with leptin (days 0 and 8, r = 0.601 and r = 0.602 respectively), These results demonstrate for the f irst time a significant reduction in leptin concentrations in normal women following bilateral ovariectomy. Although BMI seems to be the predominant f actor, it is also suggested that oestradiol and progesterone may participat e in the control of leptin production during the human menstrual cycle.