Association of the TyG-grip index with incident stroke and all-cause mortality in middle-aged and older adults: a longitudinal analysis

Insulin resistance and declining physical function commonly coexist in middle-aged and older adults. Triglyceride-glucose (TyG)-derived composite indices, such as the TyG-frailty index, can capture this metabolic and functional risk, but require the assessment of multiple components, limiting their suitability for routine clinical use. In contrast, the TyG-grip index provides a single, objective, and readily accessible method. The TyG-grip index was defined as the TyG index divided by maximum grip strength, and its association with incident stroke and all-cause mortality was examined among participants in the China Health and Retirement Longitudinal Study. Using propensity-score overlap weighting, we fitted weighted Cox models with baseline and updated exposure, and a causal survival forest to explore heterogeneity of the association. During follow-up, 636 participants developed stroke and 837 died. Compared with the lowest quartile, the highest quartile of the TyG-grip index carried higher risks of stroke (time-varying model: HR 1.64, 95% CI 1.05–2.55) and all-cause mortality (HR 1.75, 95% CI 1.19–2.58), corresponding to 5-year absolute risk differences of 1.37% and 3.32%. Associations were consistent across sensitivity analyses, and heterogeneity in the mortality association was borderline. The TyG-grip index was associated with both stroke and all-cause mortality.