Serum insulin patterns and the relationship between insulin sensitivity and glycaemic profile in women with polycystic ovary syndrome

Objective To evaluate serum insulin levels and insulin sensitivity in women with polycystic ovary syndrome (PCOS) in relation to their glycaemic status. Design An observational study. Setting A tertiary-level reproductive health centre in Sri Lanka. Sample Infertile women diagnosed as having PCOS (n = 168) on the basis of the Rotterdam criteria were included in the study. Methods Glycaemic status and serum insulin values were assessed at fasting and at 2 hours after a 75-g oral glucose load and stratified as diabetes mellitus (DM) (10.12%), impaired glucose tolerance (IGT) (23.21%) and normoglycaemia (66.67%). The normoglycaemic group was restratified as groups A (10.7%), B (79.5%) and C (9.8%) on the basis of serum insulin levels, with group A having the lowest and group C the highest values. The Quantitative Insulin Sensitivity Check Index (QUICKI) scores of women with DM and IGT and those in groups A, B and C in the normoglycaemic category were compared. Main outcome measures Insulin sensitivity in these groups of women. Results Body mass index (BMI) exceeded 23 kg/m2 in 77.38% of the women. In normoglycaemic women with PCOS, insulin sensitivity was highest in group A. In groups B and C, insulin sensitivities corresponded to those found for women with IGT and DM respectively. This pattern was also reflected in the BMI. Conclusions Normoglycaemic women with PCOS are heterogeneous regarding insulin sensitivity. The treatment offered to those with DM and IGT could be extended to subgroups B and C of normoglycaemic subjects. Normoglycaemic women with PCOS with high insulin sensitivity (group A) would not qualify for this treatment.