The Polycystic Ovary Syndrome (PCOS) is frequently associated with comorbidities such as obesity, reduced glucose tolerance, hypertension, macrovascular disease and dyslipidemia. The Metabolic syndrome occurs in 30% of women with PCOS. Metformin has increasingly been used in this therapy due to its effects in reducing insulin resistance. Treatment of PCOS aims to reduce the symptoms of hyperandrogenism, regularize the menstrual cycle, reduce metabolic abnormalities, and lower the risk of type 2 diabetes mellitus and of cardiovascular disease. Additionally it is important to prevent hyperplasia and endometrial cancer, and to offer contraception to those who do not wish pregnancy, and to help to induce ovulation to those who do. The effectiveness of metformin in this treatment is assessed in the light of the current best evidence.
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