Review: PCOS, insulin resistance and long-term risks for diabetes and vascular disease

Abstract

Insulin resistance is an important `upstream' driver for the reproductive and metabolic abnormalities in many women with polycystic ovarian syndrome (PCOS), in particular those who are overweight or obese. They frequently exhibit visceral adiposity, glucose intolerance, a dyslipidaemia which mirrors the pattern in type 2 diabetes, low-grade inflammation, and endothelial dysfunction. They are at elevated risk for type 2 diabetes (about two to four-fold relative to weight matched controls) and cardiovascular events (current best estimates at 50% higher compared with age, body mass index matched women without PCOS). Due to higher diabetes risk, women with PCOS who have other risk factors (e.g. obesity, family history of diabetes) would benefit from screening for diabetes, although the most efficient methods to do so require further investigation. Furthermore, despite the higher relative risk for coronary heart disease (CHD), absolute CHD risk is generally low in young women and thus routine lipid measurements or blood pressure in all women with PCOS would be redundant as such measurements will probably not alter clinical management. Rather, traditional risk measures should be restricted to those with significant other risk factors e.g. family history of premature vascular disease, diabetes. Finally, although recent trial evidence does not support a significant benefit of metformin in fertility treatments for PCOS, metformin does improve metabolic profile in the short term. However, longer-term formal trials of metformin are required to better understand its metabolic and vascular benefit in PCOS. Br J Diabetes Vasc Dis 2009;9:15—18