In PCOS patients the addition of low-dose spironolactone induces a more marked reduction of clinical and biochemical hyperandrogenism than metformin alone

Background & aims: Polycystic ovary syndrome (PCOS) is characterized by ovariandysfunction and hyperandrogenism and by insulin resistance and related metabolicalterations. Both metformin and anti-androgens, such as spironolactone, are used to ameliorate the different aspects of this disorder. We investigated whether therapy with metformin plus low-dose spironolactone is more effective than metformin alone in PCOS patients. Methods and results: Fifty-six PCOS patients were randomized in two groups: group A (28 patients) was treated with metformin (1700mg/die) and group B (28 patients) was treated with metformin (1700mg/die) plus low-dose spironolactone (25mg/die). Anthropometric, hormonal and metabolic parameters were evaluated at baseline and after six months of treatment. After therapy regular menses were restored in approximately 82% of group Apatients (P<0.001) and in 68% of group B patients (P<0.001). Circulating testosterone, δ-4-androstenedione and Hirsutism Score (HS) significantly decreased in both groups. However, dehydro-epiandrosterone sulphate significantly decreased only in group B, and HS underwent a stronger reduction in group B (P<0.001). At baseline, 39/56 (69.6%) patients met the diagnostic criteria for metabolic syndrome, but only one patient met these criteria after treatment. Conclusions: This study confirms the beneficial effects of metformin in PCOS patients. It also indicates that the addition of low-dose spironolactone induces a more marked reduction of clinical and biochemical hyperandrogenism as compared to metformin alone.