Optimal waist circumference cutoff values for metabolic syndrome diagnostic criteria in a Korean rural population.

The Korean Society for the Study of Obesity (KSSO) has defined the waist circumference cutoff value of central obesity as 90 cm for men and 85 cm for women. The purpose of this investigation was to determine the corresponding waist circumference values. A total of 3,508 persons in the Korean Rural Genomic Cohort Study were enrolled in this survey. Receiver operating characteristic (ROC) curve analysis was used to find appropriate waist circumference cutoff values in relation to insulin resistance determined by homeostasis model assessment for insulin resistance (HOMA-IR), body mass index (BMI), and components of metabolic syndrome. The optimal waist circumference cutoff values were 87 cm for men and 83 cm for women by ROC analysis to HOMA-IR and 86 cm for men and 83 cm for women by ROC analysis to value with more than two components of metaobolic syndrome. By using a BMI > or =25 kg/m(2), 86 cm for men and 82 cm for women were optimal waist circumference cutoff values. In this study, we suggest that the most reasonable waist circumference cutoff values are 86-87 cm for men and 82-83 cm for women.

Short insulin tolerance test can determine the effects of thiazolidinediones treatment in type 2 diabetes.

PURPOSE: The short insulin tolerance test is a simple and reliable method of estimating insulin sensitivity. This study was designed to compare the insulin sensitizing effects of thiazolidinediones (TZDs) on the degree of insulin resistance, determined by a short insulin tolerance test (Kitt) in type 2 diabetic patients. PATIENTS AND METHODS: Eighty-three subjects (mean age = 57.87 +/- 10.78) with type 2 diabetes mellitus were enrolled and received daily one dose of rosiglitazone (4 mg) or pioglitazone (15 mg). The mean follow-up duration was 25.39 +/- 9.66 months. We assessed insulin sensitivity using HOMA-IR and the short insulin tolerance test before and after TZDs treatment. RESULTS: When we compared patients' characteristics before and after TZDs treatment, the mean fasting glucose level was significantly decreased (183.27 +/- 55.04 to 137.35 +/- 36.42 mg/dL, p < 0.001) and the mean HbA1C level was significantly decreased (9.24 +/- 1.96 to 8.11 +/- 1.39%, p < 0.001). Also, Kitt values were significantly increased (2.03 +/- 1.14 to 2.67 +/- 0.97%/min, p = 0.003), whereas HOMA-IR was significantly decreased (2.98 +/- 0.68 to 1.04 +/- 0.24, p < 0.05). When classifying insulin resistance by Kitt values, insulin resistant subjects' values were increased (< 2.5%/min; 1.51 +/- 0.53%/min to 2.63 +/- 0.88, p < 0.001), whereas the values decreased in insulin sensitive subjects (>or= 2.5%/min; 3.50 +/- 0.75%/min to 2.75 +/- 1.12%/min, p = 0.002). CONCLUSION: The glucose lowering effects of TZDs by improving insulin resistance could be determined by using Kitt. However, Kitt may be a beneficial tool to determine TZDs' effects only when patients' Kitt values are less than 2.5%/min.