Longitudinal association between triglyceride glucose index and depression progression in middle-aged and elder adults: A national retrospective cohort study

Background and aims Psychological symptoms are prevalent among individuals with non-communicable diseases, while the longitudinal association between triglyceride glucose (TyG) index, an indicator of metabolic health, and depression progression remains unclear yet. This study aims to investigate the association of baseline TyG index and depression progression in middle-aged and elder adults. Methods and results This retrospective cohort study enrolled 8287 participants aged 45 years or above from national China Health and Retirement Longitudinal Study in visit 1 (2011–2012), which were biennially followed for depression score until visit 4 (2017–2018). Multivariate-adjusted regression models were used to evaluate the association of baseline TyG index with the individual level change rate and slope of depression score. The mean age (±SD) of participants was 58.25 ± 9.10 years, and 3806 (45.9%) were men. There was no significant difference of depression score at baseline across TyG quartile groups (P = 0.228). Participants in the highest quartile of TyG index had a 0.124 (95% CI: 0.018–0.230) higher change rate of depression score, and a 0.127 (95% CI: 0.019–0.235) higher change slope, compared to those in the lowest. The observed associations were consistent in multiple sensitivity analyses, and stable in men, the elder, and overweight people. Conclusion TyG index is positively associated with depression progression especially in men, the elder and overweight people, which provides new insights for the primary prevention of depression disorder.