Is insulin resistance an essential component of PCOS?: The influence of confounding factors.

Insulin resistance is often considered a regular component of polycystic ovary syndrome (PCOS). Many interventional studies assume a state of insulin resistance in all patients. However, the evidence is based on small samples that are often insufficient to adjust for significant confounding factors. Moreover, several studies have not confirmed differences in insulin sensitivity between women with PCOS and healthy controls, especially in non-obese patients. This debate article provides an overview of the data published regarding the presence of abnormal or normal insulin sensitivity in PCOS. In conclusion, available data offer evidence that a substantial subgroup of women with PCOS have insulin sensitivity comparable with healthy controls if matched carefully for potential confounding factors.