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/m(2) and 30 obese with BMI of 29.6 +/- 3.7 kg/m(2)] and in 15 healthy women with BMI of 21.6 +/- 1.8 kg/m(2) 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.