Association of triglyceride-glucose index and its related parameters with functional disability: evidence from the China Health and Retirement Longitudinal Study (CHARLS)

Zhihong Wei^1,2*Guanhua Nie^3,4,5Ji Li⁴Haolin Liu⁶Minxuan Ma⁷

• ¹1. Hospital-Acquired Infection Control Department， Affiliated Hospital of Jiangsu University, Zhenjiang 212001, China, Zhenjiang 2, China
• ²3.Department of Dermatology, Allergy, and Venereology, University of Lübeck, Lübeck, Germany, lubeck, Germany
• ³University of Lübeck, Lübeck, Germany
• ⁴2. Department of Nursing, Baoying People's Hospital, Yangzhou, China, Yangzhou, China
• ⁵Institute for Experimental and Clinical Pharmacology and Toxicology, Center of Brain, Behavior and Metabolism, University of Lübeck, Lübeck, Germany, lubeck, Germany
• ⁶No.965 Hospital, Joint Logistics Support Force of Chinese PLA, Jilin, China, jilin, China
• ⁷1. Hospital-Acquired Infection Control Department， Affiliated Hospital of Jiangsu University, Zhenjiang 212001, China, Zhenjiang, China

Background: The triglyceride-glucose (TyG) index, a marker of insulin resistance, is linked to mortality in coronary artery disease, ischemic stroke, and heart failure. However, its association with functional disability remains unclear. This study explored the relationship between the TyG index, its related parameters, and functional disability. Methods: Data were obtained from the China Health and Retirement Longitudinal Study (CHARLS). Functional disability was evaluated using the Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (IADL) scales. Multivariate logistic regression and restricted cubic spline (RCS) models were used to assess the associations between TyG-related indices and the risk of functional disability. Subgroup analyses stratified by age, sex, smoking, drinking, and diabetes were performed. Additionally, propensity score matching (PSM) was applied to ensure the robustness of the findings.Results: The diagnosis rates were 1510(16.32%) for ADL limited and 2620(28.32%) for ADL-IADL limited. The TyG-related indices were significantly associated with ADL limted. [TyG index: Full adjusted OR = 1.23, 95%CI: 1.16–1.30, p < 0.001; TyG-BMI index: Full adjusted OR = 1.11, 95%CI: 1.05–1.18, p < 0.001; TyG-WC index: Full adjusted OR = 1.20, 95%CI: 1.13–1.27, p < 0.001; TyG- WHtR index: Full adjusted OR = 1.07, 95%CI: 1.01–1.14, p = 0.025]. The TyG-related indices were significantly associated with ADL-IADL limted. [TyG index: Full adjusted OR = 1.20, 95%CI: 1.14–1.26, p < 0.001; TyG-BMI index: Full adjusted OR = 1.13, 95%CI: 1.08–1.19, p < 0.001; TyG-WC index: Full adjusted OR = 1.14, 95%CI: 1.09–1.20, p < 0.001;TyG- WHtR index: Full adjusted OR = 1.13, 95%CI: 1.07–1.18, p < 0.001]. Conclusion : Our findings indicated a trend that, TyG-related indices significantly associated with increased risks of ADL limited and ADL-IADL limited populations.