Increased leptin levels in serum and peritoneal fluid of patients with pelvic endometriosis

Pelvic endometriosis is an immune-related chronic inflammatory disease, cha racterized by ectopic implants of endometrium in the peritoneal cavity and associated with increased secretion of proinflammatory cytokines and neoang iogenesis. Leptin, the adipocyte-derived hormone, has been shown to have a role in food intake, basal metabolism, and reproductive function. Leptin le vels are dynamically regulated, being elevated by inflammatory mediators an d reduced by starvation. Leptin itself can influence the proinflammatory im mune responses of CD4(+) T lymphocytes, and reports have also shown this ho rmone to be an angiogenic factor in vitro and in vivo. We investigated whet her leptin concentrations in serum and peritoneal fluid (PF) differed betwe en 13 patients with different stages of endometriosis and 15 age- and body mass index-matched controls. We found a statistically significant (P < 0.05 ) increase in leptin levels in serum (30.3 +/- 14.8 ng/mL) and PF (35.9 +/- 17.4 ng/mL) of patients with endometriosis, compared with our control popu lation (serum, 15.6 +/- 8.4; PF, 17.5 +/- 7.2 ng/mL). Regression equations, relating leptin to body mass index, were also significantly different in e ndometriosis patients, compared with controls. Higher levels of leptin were observed in the earlier stages of endometriosis than advanced-stage diseas e. These data suggest that the proinflammatory and neoangiogenic actions of leptin may contribute to the pathogenesis of endometriosis.