Triglyceride-total cholesterol-body weight index is associated with mortality in Chinese community-dwelling older adults

Background With the progression of population aging and the growing demands for health management among older adults, identifying factors influencing mortality risk is of great significance. In particular, parameters related to blood lipids and body composition warrant in-depth investigation. This study aims to examine the association between the triglyceride-total cholesterol-body weight index (TCBI) and mortality among Chinese older adults. Methods Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS). Participants enrolled in the 2011 baseline survey were followed until 2020, yielding up to 9 years of follow-up. TCBI was measured at baseline enrollment in 2011 when participants were first recruited into the cohort study, and was calculated and categorized into quartiles (Q1–Q4). Cox proportional hazards models were used to assess the association between TCBI and mortality. Restricted cubic splines with 4 knots were employed to explore potential non-linear associations. Sensitivity analysis was performed to examine the robustness of the findings, including re-running models. Results A total of 4343 individuals aged 67.8 ± 6.4 years were included in the analysis. Over the follow-up period (median 105.8 months), 150 (3.5%) deaths were documented. As TCBI values increased, the likelihood of mortality exhibited a progressive decline ( P for trend = 0.001). After multivariable adjustment for age, sex, educational attainment, smoking status, drinking status, cardiovascular disease, diabetes, hypertension, and dyslipidemia, the highest TCBI quartile (Q4) was associated with a 61% reduction in mortality risk compared with the lowest quartile (Q1) (adjusted hazard ratio 0.39, 95% confidence interval 0.23–0.68). A linear inverse relationship between TCBI and mortality was confirmed by restricted cubic spline analysis ( P for nonlinear = 0.480). Sensitivity analyses yielded consistent results, supporting the robustness of the findings. Conclusion Elevated TCBI levels are associated with a reduced risk of all-cause mortality among Chinese older adults. These findings suggest that TCBI may serve as a practical and valuable biomarker for stratifying mortality risk in geriatric health assessments.