Clinical and biochemical indicators of homeostasis model assessment-estimated insulin resistance in postmenopausal women

Background: Homeostasis model assessment of insulin resistance (HOMA-IR) is a surrogate estimate of directly measured insulin resistance that been robustly proven to be associated with diabetes and cardiovascular disease. The purpose of this study was to evaluate the use of several simple indicators to identify postmenopausal women with insulin resistance estimated by HOMA-IR. Methods: We recruited 262 naturally postmenopausal women without overt diabetes for the study. HOMA-IR values were calculated from fasting glucose and insulin levels. Multiple linear regression analyses were carried out to detect determinants of HOMA-IR. Insulin resistance was conventionally defined as the upper quartile of the HOMA-IR values. The diagnostic power of clinical and biochemical markers for insulin resistance was assessed using receiver operating characteristic curves. Results: Some 90% of the women with HOMA-IR ≥ 2.8 (75th percentile as cutoff) showed abnormal glucose metabolism and 45% of them had silent diabetes (odds ratio 6.09, 95% CI 3.17 – 11.73 vs. those with HOMA-IR < 2.8). Results revealed that uric acid, body mass index, waist circumference, alanine aminotransferase, triglycerides, and high-density lipoprotein cholesterol were important determinants of HOMA-IR in these women. Using uric acid ≥ 5.0 mg/dL as a cutoff point, we could diagnose insulin resistance with 75.4% sensitivity and 73.1% specificity. Conclusion: Postmenopausal women with HOMA-IR-estimated insulin resistance were at high risk of glucose abnormalities in this study. High HOMA-IR values were significantly associated with six clinical and biochemical indicators. Among these, high serum uric acid levels seemed to be a useful marker identifying postmenopausal women with insulin resistance. This study was registered at clinicaltrials.gov as NCT00945271