Circulating leptin concentrations in women with hirsutism.

Objective: To evaluate serum leptin concentrations in hirsute women.

Design: Controlled clinical study.

Setting: Tertiary institutional hospital.

Patient(s): Thirty-three hirsute women and 11 healthy female controls.

Intervention(s): Serum samples were obtained at baseline and on day 1 (gonadal stimulation) and day 21 (gonadal suppression) after the IM injection of a single 3.75-mg dose of triptorelin.

Main Outcome Measure(s): Leptin, T, sex hormone-binding globulin (SHBG), insulin, and glucose levels and free androgen index.

Result(s): Leptin levels were increased in hirsute women in comparison with control subjects at baseline and on day 1. Leptin levels increased on day 1 compared with baseline and then decreased to baseline by day 21. Leptin levels correlated with body mass index (r = 0.76), SHBG levels (r = -0.52), free androgen index (r = 0.38), insulin levels (r = 0.46), and the glucose/insulin ratio (r = -0.38). When the effect of obesity on these results was removed by analysis of covariance and partial correlation analysis, leptin levels remained elevated only on day 1 and the only correlations that remained significant were those of leptin with insulin (r = 0.24) and the glucose/insulin ratio (r = -0.24).

Conclusion(s): The increased leptin levels found in hirsute women are related mainly to obesity and also to insulin resistance. Leptin levels increased during gonadal stimulation and returned to baseline during gonadal suppression, suggesting that leptin also is influenced by the gonadal axis.