Background: Metabolic factors play a critical role in the onset of lower limb joint pain, especially in middle-aged and older individuals. TyG and its derivatives, have emerged as promising indicators of insulin resistance, and are linked with several metabolic diseases, yet their relationships with lower limb joint pain remains insufficiently studied. Methods: This study utilized 9-year longitudinal data (2011– 2020) from the China Health and Retirement Longitudinal Study (CHARLS). TyG and its derivatives were collected at baseline (2011). Incident lower limb joint pain was recorded during follow-up. The associations were evaluated using Multivariable Cox proportional hazards models, Restricted Cubic Spline (RCS), and Kaplan-Meier curves. The robustness of the findings was assessed by Fine-Gray competing risk model and subgroup analyses. Results: Among 6817 participants, 2909 (42.67%) developed lower limb joint pain. The highest incidence occurred in the fourth quartile of TyG-BMI, TyG-WHtR and TyG-WC, but not TyG alone. There existed significant positive associations of TyG-BMI ( p for trend: 0.015) and TyG-WHtR ( p for trend: 0.004) with lower limb joint pain risk, especially the fourth quartiles of TyG-BMI (HR: 1.15; 95% CI: 1.02– 1.30), TyG-WHtR (1.18 1.05– 1.32) and TyG-WC (1.14 1.01– 1.27). The Fine-Gray competing risk model confirmed this robust association, and RCS indicated significant positive linear relationships of TyG-BMI and TyG-WHtR with new-onset lower limb joint pain. Subgroup analysis identified gender as a significant interactive factor for TyG-BMI, with a notable association in females. These results suggested that TyG derivatives, specifically adiposity-integrated indices, were associated with an increased risk of new-onset lower limb joint pain in middle-aged and older individuals, rather than TyG alone. Conclusion: These results highlight the importance of monitoring TyG derivatives, specifically adiposity-integrated indices (TyG-BMI and TyG-WHtR) for early clinical detection and intervention in high-risk individuals, and offer novel perspectives for the assessment and treatment of lower limb joint pain. Keywords: lower limb joint pain, CHARLS, triglyceride-glucose index, triglyceride-glucose derivatives, longitudinal study
Xue et al. (Sun,) studied this question.