The quantitative insulin sensitivity check index is not able to detect early metabolic alterations in young patients with polycystic ovarian syndrome

Objective. To verify whether QUICKY is a suitable method for the identification of metabolic deterioration in normal weight patients affected by polycystic ovarian syndrome (PCOS). Design. Prospective clinical study. Patient(s). Seventy-nine PCOS normal weight adolescent subjects, 50 eumenorrheic, normal weight, non-hirsute controls matched for age and BMI. Method(s). Quantitative insulin sensitivity check index (QUICKY) and integrated secretory area under the curve of insulin values (I-AUC) during oral glucose tolerance test were calculated. Result(s). Seventy-nine PCOS and 50 controls were studied. Normal insulin sensitivity was defined as upper control 95th percentile by QUICKY values <0.31, I-AUC at 180 min < 16,645. When applying the calculated I-AUC cut-off, 41 PCOS were classified as normoinsulinemic and 38 as hyperinsulinemic, whereas using the calculated QUICKY cut-off, only 19 PCOS could be classified as insulin resistant (IR). Fifteen out of the 60 non-IR PCOS presented hyperinsulinemia; fasting glucose and insulin levels and QUICKY were not sufficient to identify these subjects. Thus, QUICKY displayed a low sensitivity (44%) and specificity (91%) in the diagnosis of the metabolic disorder disclosed by I-AUC. Conclusions. In young normal weight patients with PCOS the prevalence of early alterations of insulin metabolism are not detectable by QUICKY studies.