CTI-related composite adiposity indices and future cardiovascular disease risk among middle-aged and older Chinese...

Composite biomarkers integrating inflammation, glycolipid metabolism, and adiposity may improve cardiovascular risk stratification, but evidence remains limited for CTI-related composite adiposity indices. This study investigated their associations with incident cardiovascular disease (CVD) and predictive performance.

This prospective cohort study included 5,290 adults aged ≥45 years without baseline CVD from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2020). Four CTI-related composite indices were evaluated: CTI-body mass index (CTI-BMI), CTI-body roundness index (CTI-BRI), CTI-Waist-to-height ratio (CTI-WHtR), and CTI-weight-adjusted waist index (CTI-WWI). Associations with incident CVD were assessed using Kaplan-Meier analysis, Cox regression, restricted cubic splines, time-dependent receiver operating characteristic curves, concordance index (C-index) analyses, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and sensitivity analyses.

During follow-up, 1,340 participants developed CVD, accounting for 25.33% of the study population. Kaplan-Meier analysis showed significant differences across tertiles for all four indices. After adjustment for demographic characteristics, lifestyle factors, clinical history, laboratory indicators, and hypertension status, all four indices remained positively associated with incident CVD. Compared with the lowest tertile, the highest tertile was associated with significantly higher CVD risk, with hazard ratios ranging from 1.37 to 1.58. Restricted cubic spline analyses showed statistically significant nonlinear associations for all indices, while exploratory two-piecewise Cox models did not establish definitive clinical thresholds. At 4-year follow-up, CTI-WHtR showed the highest area under the curve (AUC) value (0.564). Adding CTI-WHtR improved the 4-year AUC from 0.596 to 0.608, with an NRI of 0.053 and an IDI of 0.005. Sensitivity analyses yielded consistent results.

CTI-based composite adiposity indices were independently associated with incident CVD, and CTI-WHtR showed the numerically highest standalone 4-year AUC. However, its incremental predictive improvement beyond the baseline model was modest, suggesting that CTI-WHtR may be interpreted as a supplementary risk marker rather than a standalone prediction tool.