Two weeks of metformin improves clomiphene citrate-induced ovulation and metabolic profiles in women with polycystic ovary syndrome

ObjectiveTo determine if short courses of metformin (MET) administration in patients with polycystic ovary syndrome (PCOS) would reduce fasting insulin and improve the efficacy of clomiphene citrate (CC) to induce ovulation.DesignA randomized prospective trial involving 31 subjects with PCOS and infertility.SettingUniversity-based medical center.Patient(s)Obese patients (body mass index > 29 kg/m2) with PCOS.Intervention(s)Patients with PCOS were treated either with CC or CC+MET for 2 weeks.Main Outcome Measure(s)Ovulation as determined by serum P, serum insulin, and total and free T.Result(s)In the CC/MET group, a significant increase in sex hormone–binding globulin (SHBG) levels, a decrease in fasting insulin, and an increase in fasting glucose/fasting insulin was detected on day 21 of the cycle. Of these parameters, only SHBG levels increased significantly in the CC group. In the CC/MET group, a significant increase in day 21 progesterone occurred, with 44% of subjects ovulating in the CC+MET group as compared with 6.7% in the CC group. Five subjects in the CC+MET group and none in the CC group conceived. Total and free testosterone levels did not change significantly for either group.Conclusion(s)In obese PCOS patients, 2 weeks of MET significantly reduces serum insulin and insulin resistance and increases SHBG levels, resulting in an improved response to CC. This regimen may be beneficial in noncompliant patients or those with intolerance to the side effects of MET.