The Metformin-Induced Changes on BMI, TSH, and Thyroid Hormones Profile of Patients with Polycystic Ovarian Syndrome

Objective: The aim of this prospective study was to investigate the effect of metformin on BMI, TSH, thyroid hormones profile, and some clinical symptoms in 32 women with PCOS. Methods: The patients received metformin at a dose of 500 mg/day which was gradually increased to 1500 mg/day and continued for 3 months. The level of BMI, TSH, T4, and T3 was measured at baseline, 3 months after treatment with metformin and 3 months after drug withdrawal. The association of metformin therapy with prevalence of constipation, hypersomnia, cold intolerance, and dry skin was also determined in these times. Results: Three months after treatment with metformin, mean BMI and TSH was significantly decreased from baseline to 28.34±2.5 kg/m2 and 2.27±0.89 μUI/ml, respectively. There was no significant difference in TSH levels before treatment and 3 months after drug withdrawal. Mean T3 and T4 levels was slightly increased during metformin therapy and significantly decreased after drug withdrawal. Treatment with metformin significantly decreased the prevalence of hypersomnia and dry skin in patients. Conclusion: The effect of metformin on TSH and thyroid hormones profile gives us an idea about the efficacy of metformin as a sole therapy or as an adjuvant in patients with PCOS and subclinical hypothyroidism, respectively.