Comparative Evaluation of Five Obesity Indices for Cardiovascular and All-Cause Mortality Prediction in Prediabetes and Diabetes Population: A Prospective Cohort.
Abstract
Background
In the US population, the association and predictive performance of obesity indices -- Body Mass Index (BMI), Body Shape Index (ABSI), Body Roundness Index (BRI), Waist Circumference (WC), and Waist-to-Height Ratio (WHtR) with mortality outcomes Cardiovascular Mortality (CVM) and All-Cause Mortality (ACM)) in prediabetes and diabetes (DM) populations have not been systematically evaluated.
Methods
Utilizing NHANES data (prediabetes: n = 10,988, DM: n = 5,868), we evaluated these associations and predictive ability using Kaplan-Meier curves, multivariable Cox proportional hazards models, Restricted Cubic Splines (RCS), and time-dependent ROC analysis, and performed subgroup analyses to assess heterogeneity.
Results
BMI/BRI/WC/WHtR generally displayed patterns consistent with the "obesity paradox", while ABSI did not clearly conform to this paradox. In two-piecewise Cox models, ABSI was not associated with CVM but demonstrated a significant, non-paradox association with ACM in DM at higher ABSI levels. RCS revealed nonlinear associations for BMI/BRI/WC/WHtR, while ABSI showed a nonlinear association only with ACM (inflection point: prediabetes = 0.82, DM = 0.77). In unadjusted ROC analyses, ABSI generally showed higher discriminative ability for mortality outcomes; however, after full adjustment, AUC values became similar across indicators. Subgroup analyses further indicated that the predictive performance of these indicators varied across different smoking statuses, race, and sex.
Discussion
The "obesity paradox" observed in BMI/BRI/WC/WHtR likely reflects their inability to distinguish fat from muscle. ABSI, which primarily captures central adiposity, did not clearly conform to this paradox; however, its incremental predictive value diminished after adjustment, suggesting substantial overlap with conventional risk factors.
Conclusion
Unlike BMI, BRI, WC, and WHtR, ABSI did not display a clear "obesity paradox" pattern and showed higher unadjusted discrimination for mortality outcomes, although this advantage was attenuated after full adjustment, suggesting it may provide complementary risk information.