[Leptin in patients with polycystic ovary syndrome. Direct correlation with insulin resistance].

Up to now it is unclear whether there is a relationship between insulin resistance and circulating leptin levels (LEP) in women with polycystic ovary syndrome (PCOS). To assess the role of LEP in PCOS and to clarify the relationship between plasma LEP levels and insulin resistance (IR) in PCOS patients, we studied 49 women with PCOS and 14 normal premenopausal women. All subjects were evaluated by a 2 hours, 75 g, oral glucose tolerance test. Fasting plasma LEP, insulin, glucose, insulin sensitivity indexes and LEP:body mass index (BMI) were determined. Results were analyzed by ANOVA and the Pearson's correlation test when appropriate. The results indicate that: 1) no differences were found in basal plasma LEP levels (ng/ml) between normal (17.6 +/- 4.9) and PCOS (21.9 +/- 2.8) women; 2) in PCOS patients, a significant (P < 0.01) correlation between plasma LEP levels and BMI and insulin sensitivity indexes were found; and 3) seventeen PCOS patients were insulin resistant (IR) and showed higher basal plasma LEP levels (32.8 +/- 4.3, P < 0.01) and LEP:BMI (0.95 +/- 0.09, P < 0.05) than non insulin resistant (non IR) PCOS subjects (16.2 +/- 3.2 and 0.61 +/- 0.08, respectively). Our results suggest that PCOS seems to be associated with normoleptinemia, however, if IR are analyzed separately from non IR PCOS patients, there is a clear relationship between IR PCOS and hyperleptinemia, regardless of the BMI. The present study strongly supports bi-directional relationship between fat and carbohydrate metabolisms under a very particular physiopathological condition (PCOS).