Urinary 6-sulfatoxymelatonin excretion in hyperandrogenic women with polycystic ovary syndrome: the effect of ethinyl estradiol-cyproterone acetate treatment.

The role of melatonin in human reproduction is still unknown. Data obtained in patients with hypogonadism and precocious puberty suggest that melatonin and the reproductive hormones are interrelated. The aim of this study was to determine melatonin production in hyperandrogenic women. We studied 12 women with polycystic ovary syndrome (PCOS) and 10 women with idiopathic hirsutism (IH). Patients were treated with cyproterone acetate-ethinyl estradiol (Diane 35) for 4 months. Fasting blood samples for the determination of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and dehydroepiandrosterone sulfate (DHEAS) and 24-h urine collections for the determination of 6-sulfatoxymelatonin (alpha MT6s) excretion were obtained from all patients at baseline and after 4 months of treatment. The results were compared with those obtained in 15 control women. At baseline, women with PCOS had significantly higher LH and testosterone levels than those with IH and controls. Their alpha MT6s values (52.6 +/- 20.3 micrograms/24 h) were significantly higher than the values in women with IH (34.3 +/- 7.1) and controls (30.5 +/- 6.5) (p < 0.001). Diane 35 treatment significantly decreased LH, FSH, testosterone and alpha MT6a values in PCOS (28.0 +/- 13.9 micrograms/24 h) (p < 0.0001). These results indicate that women with PCOS have increased melatonin production. The normalization of alpha MT6s and testosterone values during Diane 35 treatment suggests that sex steroids modulate melatonin secretion in these patients either directly or through the suppression of gonadotropin.