Does obesity diminish the positive effect of oral contraceptive treatment on hyperandrogenism in women with polycystic ovarian syndrome?

Polycystic ovarian syndrome (PCOS) is an obvious indication for long-term treatment. Combined oral contraceptives (COC) remain the first choice for the treatment of hyperandrogenism in most patients. However, differences in endocrine and metabolic parameters between obese and lean patients have been postulated. This is the first study evaluating the effect of COC treatment in obese versus non-obese PCOS patients. In total, 28 lean [body mass index (BMI) <25 kg/m(2))] and 15 obese (BMI >30 kg/m(2)) women patients were enrolled in the study. The concentrations of androgens, sex hormone-binding globulin (SHBG) and lipids were measured before and after 6 months of treatment with COC containing low-androgenic progestins. Clinical androgenic symptoms were monitored. There was a lower concentration of SHBG in obese patients, but there were no differences in androgen concentrations between both groups before the study. Highly significant changes in concentrations of testosterone (P < 0.001), androstenedione (P < 0.0001), SHBG (P < 0.001) and LH (P = 0.01) were demonstrated in lean patients, with only less significant changes in SHBG (P < 0.01) and testosterone (P < 0.05) in obese patients during the study. Clinical androgenic symptoms improved significantly (P = 0.05) only in the group of lean women. No reduction in low-density lipoprotein-cholesterol/high-density lipoprotein-cholesterol ratio was observed in either group. In conclusion, the positive effect of COC treatment on androgen production, serum androgen binding capacity, and clinical androgenic symptoms was negatively influenced by an increased BMI.