Insulin resistance and the long-term consequences of polycystic ovary syndrome.

In a significant number of women with the polycystic ovary syndrome there is impaired insulin metabolism with hypersecretion of insulin. Insulin resistance is defined as a diminution in the glucose response to a given amount of insulin. Insulin resistance has been implicated in the pathogenesis of many aspects of the syndrome. Hyperinsulinaemia leads to increased production of androgens resulting in anovulatory infertility. Women and particularly obese women with insulin resistance and the polycystic ovary syndrome have an increased risk of developing gestational diabetes and also type 2 diabetes and cardiovascular disease in later life. The women should be counselled about long-term health risks, and obese women with the polycystic ovary syndrome should be periodically screened. Lifestyle modification to reduce weight in obese women and treatment with insulin-sensitising drugs such as metformin in women with glucose intolerance result in the improvement of some metabolic abnormalities and hyperandrogenic disorders with the consequent restoration of normal menstrual and ovulatory function in a significant number of women with polycystic ovaries.