An analysis of the relationship between insulin resistance and the activity of steroid C17,20-lyase and 3 beta-hydroxysteroid dehydrogenase in ovaries and adrenals in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is connected with insulin resistance (IR), and often with the hypersecretion of adrenal androgens. Mutual relationshi ps between IR and adrenal and ovarian steroidogenesis were investigated in the group of 19 oligo/amenorhoeic women with PCOS. The age and body mass in dex (BMI) of the patients were 21 +/- 4.7 years and 26.4 +/- 5 kg/m2 (avera ge+/-SD), respectively. All underwent a 60-minute adrenocorticotrophic horm one (ACTH) stimulation test, a gonadoliberin analogue (GnRHa) test with bus erelin and an oral glucose tolerance test (oGTT) in the early follicular ph ase of the menstrual cycle. When absolute stimulated steroid levels after G nRHa were studied, a significant positive correlation between DHEA and area under curve during oGTT for C peptide (AUC(.)CP) (r=0.477, p=0.039) and a borderline negative correlation (r= -0.404, p=0.087) between AUC-CP and 17- OH progesterone, were found. Considering steroid values after ACTH, a signi ficant positive correlation of IR index was found only with 17-OH-progester one (r=0.499, p=0.03). When stimulated enzymatic activities (expressed as p roduct/precursor ratios) were analyzed using factor analysis, a positive re lationship between IR and ovarian C17,20-lyase in both Delta 4 and Delta 5 pathway was revealed. On the other hand, no relationship was confirmed betw een IR and enzymatic activities in the adrenals. The authors conclude that insulin resistance and/or hyperinsulinemia is probably not the primary fact or responsible for the exaggerated adrenal androgen secretion found in a gr eat number of patients with PCOS.