Is hyperprolactinemia associated with insulin resistance in non-obese patients with polycystic ovary syndrome?

Insulin resistance is common in polycystic ovary syndrome (PCOS). Moderate elevations in serum PRL concentration may contribute to insulin resistance in PCOS. The aim of this study was to determine PRL on development of insulin resistance in non-obese hyperprolactinemic patients with PCOS. Ninety-eight non-obese subjects with PCOS and 100 non-obese healthy control were accepted in the study. Serum glucose, lipids, androgens, free androgen index (FAI), gonadotropins, fat mass and percentage, SHBG, and insulin levels were measured. Homeostasis model assessment (HOMA) was used as index of pancreatic beta-cell function and tissue insulin sensitivity. Independent t-test was used in comparison of results. In patients with PCOS, FAI and mean HOMA-(%B) level were higher than in the control group (p<0.0001), whereas mean HOMA-(%S) in subjects with PCOS was lower than in the control group (p<0.0001). Patients with PCOS were divided into subgroups according to their serum prolactin level (< 24 or > or = 24 ng/ml). Although FAI was not different, mean insulin and HOMA-(%B) levels in hyperprolactinemic patients were higher than in normoprolactinemic subjects (p<0.001). HOMA-(%S) in hyperprolactinemic patients with PCOS was lower than in normoprolactinemic patients (p<0.002). In conclusion, PCOS is associated with insulin resistance; non-obese hyperprolactinemic PCOS patients may be more insulin-resistant than normoprolactinemics and there may be an association between hyperprolactinemia and insulin resistance in PCOS.