LAUSR

AIMS Obesity measurement is a vital component of most type 2 diabetes screening tests; while studies had shown that waist circumference (WC) is a better predictor in South Asians, there is evidence that BMI is also effective. Our objective was to evaluate the efficacy of BMIWC, a composite measure, against BMI and WC. METHODS Using data from a nationwide randomized cluster sample survey (NMB-2017), we analyzed 7496 adults at high risk for type 2 diabetes. WC, BMI, and BMIWC were evaluated using Risk scores (ER, RR, and OR), and Classification scores (Sensitivity, Specificity, and Accuracy). These were validated using Indian Diabetes Risk Score (IDRS) by replacing WC with BMI and BMIWC, and calculating Sensitivity, Specificity, and Accuracy. RESULTS BMIWC had higher ER, RR, and OR (0·192, 1·688, 2·300) compared to WC (0·148, 1·462, 1·870) and BMI (0·190, 1·657, 2·260). WC, BMI, and BMIWC were all highly Sensitive (0·75, 0·81, 0·70 resp.). But BMIWC had significantly higher Specificity (0.36) when compared to WC and BMI (0.27 each). IDRSWC, IDRSBMI, and IDRSBMIWC were all highly Sensitive (0·87, 0·88, 0·82 resp.). Bur IDRSBMIWC had significantly higher Specificity (0·39) compared to IDRSWC and IDRSBMI (0·30, 0·31 resp.). CONCLUSIONS Indians with high values of both central (high WC) or general (BMI> 23) obesity carry higher risk for type 2 diabetes than either one in isolation. The composite metric BMIWC is a better measure of obesity. Using BMIWC in IDRS improves its performance on Accuracy and Specificity.