Sensitivity of plasma insulin levels in obese and non-obese women with functional hyperandrogenism.

Hyperinsulinemia has been implicated in the etiology of functional hyperandrogenism (FH). In a prospective controlled trial, we determined the sensitivity and diagnostic accuracy of fasting plasma insulin levels in 37 females of reproductive age with FH, who were further subdivided into obese (body mass index (BMI) > 25 kg/m2, n = 22) and non-obese (n = 15) groups, in women with (n = 30) and without (n = 7) polycystic ovaries on vaginal endosonography and in controls of similar age (n = 29) who were body mass-matched to the non-obese FH subgroup. Insulin, testosterone, androstenedione, luteinizing hormone (LH), LH/follicle-stimulating hormone (FSH) ratio and dehydroepiandrosterone sulfate (DHEA-S) levels were measured by conventional radio-immunoassay. All hormonal parameters, including insulin (p , 0.0001), were significantly increased in the FH group vs. controls. Mean BMI and insulin did not differ between the subgroups with and without polycystic ovaries. Only insulin was increased (p = 0.0012) in the obese FH vs. non-obese FH subgroup. In the FH group, insulin showed the highest coefficient of variation (0.76) but also the best sensitivity (0.57) and diagnostic accuracy (0.73), equal that of testosterone (0.54 and 0.73, respectively). Insulin was more sensitive (0.72) than testosterone (0.59) in the obese FH subgroup, but less sensitive (0.27) than testosterone (0.47) in the non-obese FH subgroup. Multiple correlation analysis showed a significant linear relationship (p < 0.0001) between insulin and BMI but no correlation between insulin and the other parameters.(ABSTRACT TRUNCATED AT 250 WORDS)