Association of Multiple Obesity-Related Composite Indices with All-Cause Mortality in Patients with Stage 0-3 Cardiovascular-Kidney-Metabolic Syndrome.

Abstract

Background: This study aimed to determine the predictive ability of eight composite obesity-related indices for all-cause mortality in adults with cardiovascular-kidney-metabolic (CKM) syndrome stages 0-3, given the inadequacy of conventional anthropometric measures.

Methods: We conducted a prospective cohort study using UK Biobank data, including 261,742 adults with CKM stages 0-3 at baseline. Eight indices (body mass index, relative fat mass [RFM], body roundness index [BRI], lipid accumulation product [LAP], visceral adiposity index, cardiometabolic index [CMI], atherogenic index of plasma, and triglyceride-glucose index) were evaluated using multivariable logistic regression, Cox proportional hazards models, receiver operating characteristic analysis, and restricted cubic spline (RCS) modeling to examine their associations with, and predictive ability for, all-cause mortality.

Results: During follow-up, 13,437 deaths (5.1%) occurred. All eight indices were positively associated with mortality (P<0.001). BRI was the strongest predictor (area under the curve [AUC]=0.658; optimal cutoff=4.515), outperforming LAP (AUC=0.616) and CMI (AUC=0.610). RFM exhibited the lowest discriminative ability (AUC=0.502). Higher quartiles of most indices were associated with progressively increased mortality risk, with BRI demonstrating consistent predictive value across subgroups in RCS analyses.

Conclusion: BRI showed the strongest and most consistent association with all-cause mortality in CKM stages 0-3, suggesting that it may act as a robust tool for early risk stratification and support targeted prevention strategies.