Novel obesity biomarkers as mortality predictors in individuals with CKD: a comparative analysis with traditional anthropometric measures

The a body shape index (ABSI) and body roundness index (BRI) represent novel obesity biomarkers. This study aimed to determine their predictive capabilities for mortality risk in individuals with chronic kidney disease (CKD) and to compare their performance with traditional obesity markers of body mass index (BMI) and waist circumference (WC). We performed a cohort study by analyzing 6,577 adult CKD participants (mean age 60.372 years, 43.588% men) from the 1999-2018 National Health and Nutrition Examination Survey. We determined the prognostic value of ABSI and BRI for all-cause and cardiovascular disease (CVD) mortality using the Cox proportional hazard regression analysis. We also compared the predictive performance between ABSI, BRI and BMI and WC by time-dependent receiver-operating characteristic curves. The cohort experienced 2,532 (31.7%) deaths, including 921 CVD mortality, over a median of 90 months. Compared to the lowest quartile, the hazard ratios (95% confidence intervals) for the highest quartile of ABSI and BRI were 3.320 (2.803-3.934) and 1.157 (1.019-1.315), respectively, for all-cause mortality, and 3.796 (2.971-4.850) and 1.319 (1.041-1.671), respectively, for CVD mortality. Dose-response analysis revealed a positive and linear relationship between ABSI and mortality. A nonlinear relationship was identified between BRI with all-cause and CVD mortality. ABSI consistently outperformed BRI, BMI, and WC in predicting all-cause and CVD mortality across almost all follow-up periods. Thus, ABSI emerges as a promising obesity biomarker for predicting all-cause and CVD mortality risk in US adults with CKD, supporting its incorporation into routine CKD prognostication assessment.