Long-term naltrexone treatment reduces the exaggerated insulin secretion in patients with polycystic ovary disease.

Objective: To evaluate the involvement of endogenous opiates in the pathophysiology of the hyperinsulinism in patients affected by polycystic ovary disease by administering naloxone and naltrexone. We also studied the hormonal status following long-term opioid antagonist administration.
Methods: Twenty-one women affected by polycystic ovary disease participated in the study. An oral glucose tolerance test (GTT) was performed at baseline and repeated after short-term naloxone infusion and after 6 weeks of naltrexone administration. Plasma glucose and insulin levels were evaluated in all samples. Gonadotropins, sex hormone-binding globulin, and androgen levels were determined initially and after the naltrexone treatment.
Results: None of the patients showed any alteration of glucose tolerance. Based on the insulin response to the GTT, the patients were classified as normo- or hyperinsulinemic. Opioid antagonist administration significantly reduced the insulin response to the GTT in hyperinsulinemic patients, without affecting their glycemic levels. In normoinsulinemic patients, glucose plasma levels were increased whereas insulin levels were not modified by the treatments. Gonadotropin and androgen plasma concentrations were not modified after naltrexone administration.
Conclusions: This work supports a role for the endogenous opiates in the regulation of exaggerated insulin secretion in patients with polycystic ovary disease. The reduction of insulin secretion failed to demonstrate any hormonal modification in such hyperandrogenized patients.