Evaluating the performance of a novel anthropometric index: weight adjusted for waist-to-height ratio (W-WHR) – for predicting cardiometabolic risk among adults in Addis Ababa

Abstract

ObjectiveVarious anthropometric indices had been proposed to predict cardiometabolic risk, yet few were validated in the African population. We evaluated the diagnostic accuracy of a novel anthropometric index—weight adjusted for waist-to-height ratio (W-WHR)—as a predictor of cardiometabolic risk among adults 18–64 years in Addis Ababa, Ethiopia; and compared its performance with other indices commonly used in the literature.DesignCross-sectional study.SettingCommunity-based study in Addis Ababa, Ethiopia.ParticipantsRandomly selected adults (n=600) completed serum lipid, blood pressure, blood glucose and anthropometric measurements.Primary and secondary outcome measuresThe primary outcomes of interest were dyslipidaemia, hypertension and hyperglycaemia. Having at least one of the three outcomes was considered as a secondary outcome. Receiver-operating characteristic curve (ROC) used to measure the diagnostic accuracy of W-WHR and another 13 indices for predicting the primary and secondary outcomes. Optimal thresholds were determined using Youden’s index.ResultsW-WHR demonstrated an acceptable diagnostic accuracy (area under the curve (AUC), 95% CI) for correctly classifying dyslipidaemia (0.80, 0.76 to 0.84), hypertension (0.74, 0.70 to 0.78), hyperglycaemia (0.76, 0.70 to 0.82) and the secondary outcome of interest (0.79, 0.75 to 0.83). Depending on the outcomes, thresholds between 32.6 and 36.7 concurrently maximised sensitivity and specificity of the index. ROC analysis indicated, W-WHR (AUC=0.80), abdominal volume index (AVI) (AUC=0.78) and waist circumference (WC) (AUC=0.78) for dyslipidaemia; W-WHR (AUC=0.74) and WC (AUC=0.74) for hypertension; and waist-to-height ratio (AUC=0.80) and body roundness index (AUC=0.80) for hyperglycaemia, had the highest diagnostic accuracy. Likewise, W-WHR (AUC=0.79), AVI (AUC=0.78) and WC (AUC=0.78) had better performance for the secondary outcome. Most indices have better utility among younger than older adults, and per cent body fat had the highest diagnostic accuracy among women (AUC 0.74–0.83).ConclusionW-WHR is a useful index for predicting cardiometabolic risk, especially among young adults.