Body weight, hyperinsulinemia, and gonadotropin levels in the polycystic ovarian syndrome: evidence of two distinct populations.

OBJECTIVE

To investigate the impact of body weight (BW) and insulin levels on gonadotropin and androgen levels in women with the polycystic ovarian syndrome (PCOS).

DESIGN

Comparative study of endocrinologic parameters in PCOS women.

SETTING

University Hospital Reproductive Endocrinology Unit.

PATIENTS: Thirty obese and 19 nonobese women with PCOS. Seven obese and 7 nonobese normal women.

MAIN OUTCOME MEASURES: Serum concentrations of insulin, testosterone, androstenedione, luteinizing hormone (LH), follicle-stimulating hormone. Serum LH response to gonadotropin-releasing hormone (GnRH) administration and assessment of insulin resistance by the continuous infusion of glucose with model assessment (CIGMA) test.

RESULTS

Fasting insulin levels correlated with body mass index (BMI). Basal LH levels correlated inversely with BMI. Nonobese women with PCOS had a higher LH response to GnRH than obese women with PCOS. Only obese women with PCOS showed insulin resistance and fasting hyperinsulinemia.

CONCLUSIONS

The data suggest that women with PCOS may be divided into two subgroups: those with obesity, insulin resistance, hyperinsulinemia, and normal/minimally elevated LH levels and those with normal BW, elevated LH levels, and normoinsulinemia.