Metformin or antiandrogen in the treatment of hirsutism in polycystic ovary syndrome

Hirsutism is a common and distressing symptom frequently encountered in women with polycystic ovary syndrome (PCOS), who also show relative insulin resistance. The aim of this trial, in which hirsutism was the primary end point, was to compare the efficacy of the oral antihyperglycemic medication metformin with that of an established treatment, combined ethinyl estradiol and cyproterone acetate. Patients (n = 52) were randomized to receive either metformin (500 mg, three times daily) or Dianette (ethinyl estradiol, 35 micro g; cyproterone acetate, 2 mg) treatment for 12 months, with assessments before treatment, at 6 months, and at 12 months. Both objective and subjective methods of evaluating hirsutism were used, and in addition, patient perceptions were examined. The results show that metformin is potentially an effective treatment for moderate to severe hirsutism in women with PCOS. They also suggest that in some respects (Ferriman-Gallwey score and patient self-assessment), it is more efficacious than the standard treatment (Dianette). The objective evaluation of hair diameter reduction showed that both treatments were moderately effective at multiple anatomical sites. Dianette treatment was responsible for profound suppression of androgen activity, in contrast to metformin, which induced negligible change. However, metformin did reduce markers of insulin resistance. The data suggest that hirsutism may be effectively treated by reducing hyperinsulinemia.