Insulin sensitivity in women with polycystic ovary syndrome

The aim of our study was to compare insulin sensitivity in lean and obese European polycystic ovary syndrome (PCOS) women with lean healthy women. We performed the euglycemic hyperinsulinemic clamp in 83 women with PCOS [53 lean with body mass index (BMI) of 21.5 +/- 1.8 kg/m2 and 30 obese with BMI of 29.6 +/- 3.7 kg/m2] and in 15 healthy women with BMI of 21.6 +/- 1.8 kg/m2 to determine glucose disposal (M) and the insulin sensitivity index (ISI). Statistical evaluation was done using Kruskal-Wallis ANOVA followed by Kruskal-Wallis multiple-comparison z-value test. The basal blood glucose was significantly higher in lean and obese PCOS women than in controls (P < 0.02). Fasting insulin was significantly higher in both lean and obese PCOS women than in controls (P < 0.000001). Obese PCOS women were more insulin resistant than controls (P < 0.02 for M and P < 0.0008 for ISI); lean PCOS women did not differ from controls in M or ISI. Posthepatic insulin delivery was significantly higher in both lean and obese PCOS women compared with controls (P < 0.000008). We conclude that lean PCOS women are not more insulin resistant than healthy controls. Insulin hypersecretion, on the other hand, is present even in lean PCOS women.