Clinical features and circulating gonadotropin, insulin, and androgen interactions in women with polycystic ovarian disease

Objective: To investigate the interactions of hyperinsulinemia and inappropriate gonadotropin secretion in women with polycystic ovarian disease (PCOD). Design: Comparative study of endocrinologic parameters in subjects with PCOD. Setting: Open patient clinic of reproductive endocrinology at University Central Hospital of Turku, Finland. Patients: Fourteen nonobese and 10 obese patients with PCOD. Seven healthy women for reference data collection. Normal thyroid function, serum prolactin concentration, normal diurnal cortisol variation, euglycemia in all subjects. Main Outcome Measures: Serum concentrations of insulin, testosterone, androstenedione, dehydroepiandrosterone sulfate, sex hormone-binding globulin, immunoreactive luteinizing hormone (LH), bioactive LH, and follicle-stimulating hormone (FSH). Results: The concentration of insulin was higher and that of bioactive LH was lower in obese than in nonobese PCOD women in whom the levels were also above the upper reference value. There was a negative correlation between insulin and bioactive LH levels (r = -0.57). Bioactive LH correlated inversely with the body mass index (BMI) (r = -0.50). After eliminating the effect of the BMI, the correlation between bioactive LH and insulin was no longer significant (r = -0.37). The bioactive LH and immunoreactive LH/FSH ratio correlated significantly (r = 0.68). Conclusions: These data demonstrate that hyperandrogenic women can be divided into two subgroups: those with insulin resistance, normal or minimally elevated LH, and markedly elevated insulin levels; and those with elevated LH levels, no insulin resistance, and normal insulin concentrations. Obesity is associated with the former, and high bioactive LH levels with the latter subgroup.