Prevalence of insulin resistance in Korean women with polycystic ovary syndrome according to various homeostasis model assessment for insulin resistance cutoff values.

OBJECTIVE:To investigate the various homeostasis model assessment for insulin resistance (HOMA-IR) cutoff values in a large population of healthy controls and to evaluate the prevalence of IR in women with polycystic ovary syndrome (PCOS). DESIGN:Case control study. SETTING:Reproductive endocrinology center. PATIENT(S):Women with (n = 699) and without PCOS (n = 572). INTERVENTION(S):Blood tests. MAIN OUTCOME MEASURE(S):The upper 75th and 95th percentiles of HOMA-IR in lean controls (n = 522) and the HOMA-IR cutoff that indicates metabolic risk in all participants. RESULT(S):HOMA-IR cutoffs of 1.82 and 3.16 were defined as above the 75th and 95th percentiles in lean controls, and the prevalence of IR in patients with PCOS was 60.7% and 24.5%, respectively. The optimal HOMA-IR for the diagnosis of metabolic syndrome was 2.64; thus, metabolic risk was increased at a lower level of HOMA-IR compared with the 95th percentile cutoff. At HOMA-IR cutoff of 2.64, 34.8% of patients with PCOS had evidence of IR. Metabolic features significantly differed between patients with PCOS with and without IR, and patients with PCOS without IR showed similar or more favorable metabolic features compared with controls. Overweight/obese patients are the most high-risk group, but lean patients also showed a similarly elevated prevalence of IR as overweight/obese controls. A positive correlation was observed between BMI and HOMA-IR in both patients and controls, but the magnitude was significantly greater in patients than in controls. CONCLUSION(S):Although IR is common in women with PCOS, it does not seem to be universal, and patients without IR had reassuring metabolic features.