INSULIN RESISTANCE AND POLYCYSTIC OVARY SYNDROME IN A CHINESE POPULATION

Our study aimed to investigate glucose and lipid level as well as insulin resistance (IR) in patients with polycystic ovary syndrome (PCOS).

In a case-control study, 426 patients with PCOS were diagnosed according to Rotterdam criteria, and they were conducted in the morning after a 10-h fast. Participants received standard 75-g oral glucose tolerance test (OGTT). Plasma glucose and insulin levels were obtained at 0, 30, 60, 120, and 180 min. They also received the lipid evaluation; 95 healthy women with normal menstrual cycles served as controls. Thus, by modifying the homeostasis model assessment of insulin resistance (HOMA-IR) with the use of individual time-course values of glucose and insulin plasma levels, we developed a new assessment method, HOMA-Mx.

In our study, 23.71% of patients had abnormal glucose metabolism. With further impairment in glucose metabolism, the glucose and lipid level gradually increased (P<0.05), while the impaired glucose regulation (IGR) group showed greater insulin response than a type 2 diabetes mellitus (T2DM) group. Compared with healthy controls, both lean and obese PCOS patients with normal glucose tolerance (NGT) had a higher body mass index (BMI), and higher serum glucose, insulin, and lipid values. Additionally, the insulin value peaked at 30 min and 60 min in the lean and obese groups, respectively. HOMA-M30 proved to be the best predictive parameter (cutoff: 20.36, area under the curve [AUC]: 0.753) for assessment of IR in normal-weight patients and HOMA-IR (cutoff: 32.17, AUC: 0.868) was optimal in obese PCOS patients.

A new assessment method was developed for these groups: HOMA-M30 for lean PCOS patients and HOMA-M60 for obese patients, in order to focus on peak insulin values for early detection of IR.