Elevated plasma levels of β-endorphin in a group of women with polycystic ovarian disease

Abstract

The relationship of endogenous opiates in patients with polycystic ovarian disease (PCOD) and their influence on body weight was studied. The study group consisted of 19 women with PCOD. They were amenorrheic, hirsute, and hyperandrogenic, and their average weight was 124% of the ideal body weight. They had luteinizing hormone/follicle-stimulating hormone ratios greater than or equal to 2. The control group consisted of ten women with regular ovulatory menses. Plasma beta-endorphin (beta-EP) was measured by using a very specific radioimmunoassay. beta-Lipotropin (beta-LPH) was entirely removed from the sample by preincubation of the plasma with rabbit anti-beta-LPH/Sepharose complex (Pharmacia, New Brunswick, NJ). The mean +/- standard deviation of the plasma beta-EP in the control group was 70.18 +/- 18.06 pg/ml, and the mean +/- standard deviation of beta-EP in the study group was 185.6 +/- 93.4 pg/ml, which was significantly higher than the control levels (P less than 0.001). A significant correlation was also found between plasma beta-EP level and the patient's weight in the PCOD group (r = 0.462, P = 0.025). The data from this study suggest that the elevated levels of endogenous opiates may be involved in the pathophysiology of PCOD and be related to inappropriate secretion of gonadotropins influencing body weight.