Comparison of metabolic effects of metformin and rosiglitazone in the management of polycystic ovary syndrome (PCOS): A prospective, parallel, randomized, open-label study

SummaryBackground and aimsEffective treatment of polycystic ovary syndrome (PCOS) remains controversial but recently, insulin-sensitizing agents have found usage in PCOS based on the relationship between hyperinsulinemia and ovarian hyperandrogenemia. The present study was undertaken to evaluate and compare the efficacy of metformin versus rosiglitazone on insulin resistance and hyperandrogenemia in women with PCOS.MethodsIn this prospective, parallel, randomized, open-label study; insulin resistance and hyperandrogenemia were evaluated in 61 subjects with PCOS, out of which 31 subjects received metformin (850 mg/BD) and 30 subjects received rosiglitazone (2 mg/BD) for 12 months. Evaluation of insulin resistance using the homeostasis model insulin resistance index (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), area under the curve (AUC) for insulin and AUC for glucose; and evaluation of hyperandrogenemia by clinical/biochemical parameters namely, hirsutism, ovulation, resumption of menstrual cycle, and androgen levels were performed at baseline and 3,6 and 12 months, respectively.ResultsClinical manifestations of hyperandrogenemia improved in both groups. Both PCOS groups had normal levels of glucose throughout the study. Insulin levels, at baseline and months 3, 6 and 12 were 13.11 ± 2.45, 9.94 ± 2.41, 9.28 ± 3.25, 8.94 ± 2.39 and 11.38 ± 5.16, 9.55 ± 3.11, 8.22 ± 3.68, 8.02 ± 3.78 μU/ml in metformin and rosiglitazone groups respectively (P < 0.05). Corresponding HOMA values were 4.58 ± 0.22, 3.90 ± 0.19, 3.84 ± 0.20 and 2.76 ± 0.17 in metformin group (P < 0.05), and 4.19 ± 0.24, 2.77 ± 0.22, 2.58 ± 0.20 and 1.90 ± 0.16 in rosiglitazone group (P < 0.05), whereas, QUICKI values were 0.60 ± 0.02, 0.65 ± 0.02, 0.67 ± 0.02 and 0.66 ± 0.02 in metformin group (P < 0.05) and 0.63 ± 0.02, 0.68 ± 0.02, 0.72 ± 0.03 and 0.70 ± 0.02 in rosiglitazone group (P < 0.05), respectively.ConclusionMetformin and rosiglitazone improve outcome measures after treatment; rosiglitazone seems to improve insulin resistance relatively earlier; while metformin had an earlier and more sustained benefit on hyperandrogenemia.