Insulin Resistance, Polycystic Ovary Syndrome and Metformin

Polycystic ovary syndrome (PCOS) is the most common disorder of ovarian function in premenopausal women. PCOS is characterised by chronic anovulation and androgen excess with clinical manifestation of irregular menstrual cycles, hirsutism and/or acne. Insulin resistance with resultant hyperinsulinaemia, irrespective of excess weight or frank obesity, has been reported in patients with PCOS, and, as insulin has a direct effect on ovarian androgen production in vitro, insulin resistance may play a crucial role in the physiopathology of PCOS. Although the molecular mechanism(s) of insulin resistance in PCOS is unclear, excessive insulin-independent serine phosphorylation of the β subunit of the insulin receptor, as reported in some patients with PCOS, has been put forward as a new mechanism for insulin resistance.