Metformin doses and body mass index: clinical outcomes in insulin resistant polycystic ovary syndrome women

OBJECTIVE: PCOS is the most common endocrinopathy among reproductive age women. Approximately 60% of PCOS women have insulin resistance. While the efficacy of metformin in reducing insulin resistance and decreasing androgen level has been widely validated, there is no agreement on the dose of metformin to be used. PATIENTS AND METHODS: Prospective non -randomized cohort study of 108 insulin resistant, overweight and obese PCOS women, aged between 22 and 35 years. All patients received 1500 mg of metformin (500 mg x 3 times/day) for the first 6 months. At the end of this period, the patients' HOMA index was evaluated. In subjects, who did not demonstrate normalization of the HOMA index, the dose was increased to 2500 mg/day (500 mg at breakfast and 1000 mg at lunch and dinner) for additional 6 months. The hormonal blood profile, fasting insulin and fasting glucose levels, HOMA index, anthropometric assessment, pelvic ultrasound, FAI index and cholesterol were evaluated. RESULTS: Overall results showed a good response to metformin therapy in insulin -resistant PCOS patients with BMI >25, while in patients with higher BMI (31.15 0.40), no normalization of HOMA was found. At the higher dose of metformin, obese patients achieved a good response to therapy, with improvement in BMI, menstrual pattern, cholesterol levels and hyperandrogenism. CONCLUSIONS: Our results demonstrate a correlation between the required dose of metformin, BMI and hyperandrogenism. The dose of metformin should be adjusted to patients' BMI in order to obtain significant results in terms of clinical, metabolic and hormonal responses.