Background: Central obesity is strongly associated with cardiometabolic risk (CMR), but the optimal anthropometric index for routine clinical screening remains uncertain. This study compared the discriminative performance of six anthropometric indices for predicting CMR in a primary care population from Madeira Island, Portugal.

Methods: A cross-sectional study was conducted including 198 adults aged 30–74 years attending primary health centres in Madeira Island. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), waist-to-hip ratio (WHR), a body shape index (ABSI), and body roundness index (BRI) were evaluated. CMR was defined as Framingham score ≥10% and/or FINDRISC score ≥12. Correlation analyses and receiver operating characteristic (ROC) curves were used to assess associations and discriminative capacity, with area under the curve (AUC) values and 95% confidence intervals calculated, where an AUC of 1.0 indicates perfect discrimination and AUC <0.5 no better than chance.

Results: WHtR (AUC=0.859; 95% CI: 0.806–0.912) and BRI (AUC=0.860; 95% CI: 0.807–0.912) showed the highest discriminative capacity for overall CMR and type 2 diabetes risk (T2DM), outperforming BMI (AUC=0.790). WC also demonstrated strong predictive ability (AUC=0.838). For cardiovascular risk specifically, ABSI and WHR performed best, although no index showed clear superiority. The strongest correlations with overall CMR were observed for BRI (ρ=0.617) and WHtR (ρ=0.616). Optimal cut-offs for CMR prediction were WHtR ≥ 0.555 and BRI ≥ 4.50.

Conclusions: WHtR and BRI showed numerically higher discriminative capacity than BMI for CMR prediction in this primary care population. Given its equivalent predictive performance, simpler calculation, and a widely validated cut-off (≥ 0.5), WHtR may represent a practical screening tool for routine clinical use, pending confirmation in larger prospective cohorts.