Association of Cumulative Exposure and Dynamic Trajectories of Triglyceride-Total Cholesterol-Body Weight Index with New-Onset Chronic Liver Disease in Middle-Aged and Older Chinese Adults: A Longitudinal Analysis Based on CHARLS

Abstract Background: The Triglyceride-Total Cholesterol-Body Weight Index (TCBI) is a novel nutritional index, but its longitudinal association with chronic liver disease (CLD) is unclear. This study examined cumulative TCBI (cuTCBI) and TCBI trajectories in relation to incident CLD risk. Methods: Data from the China Health and Retirement Longitudinal Study (CHARLS) included 4,695 participants. TCBI trajectories were identified via K-means clustering. Cox regression, restricted cubic spline (RCS), Kaplan–Meier curves, and ROC analyses assessed associations, with subgroup and sensitivity analyses. Results: Over follow-up, 245 (5.2%) developed CLD. Each 1-SD increase in cuTCBI raised CLD risk by 12% (HR = 1.12, 95%CI:1.03–1.22). The highest cuTCBI tertile (HR = 1.51, 95%CI:1.09–2.09) and quartile (HR = 1.68, 95%CI:1.14–2.48) showed increased risk. Three trajectories (low-stable, moderate-stable, high-stable) were identified; the high-stable group had 46% higher risk versus low-stable (HR = 1.46, 95%CI:1.03–2.07). RCS revealed a linear dose–response relationship (P-overall < 0.0001; P-nonlinear = 0.1856). Kaplan–Meier curves showed higher cuTCBI linked to greater CLD incidence (p < 0.05). Associations were consistent across subgroups and robust in sensitivity analyses. Conclusions: Both cuTCBI and persistently elevated TCBI trajectories are associated with increased CLD risk in middle-aged and older adults. Long-term monitoring and maintaining low TCBI levels may aid CLD prevention.