Among 8,767 Chinese adults aged 45+ followed for a median of 108 months, combining the triglyceride-glucose (TyG) index with biological age acceleration (BAA) — derived from two validated algorithms, Light-BA and KDM-BA — predicted cardiometabolic multimorbidity (CMM) far better than either measure alone. TyG independently raised CMM hazard by 23–27% per standard deviation; biological age acceleration raised it by 39–44%. Together, the composite TyG-BA index yielded 49–62% higher risk per SD, with the highest quartile showing more than threefold greater risk than the lowest. Participants sustaining elevated exposure across two waves (2011–2015) faced 3.93–5.17 times the CMM risk of low-exposure peers.
This preprint, not yet peer-reviewed, addresses a meaningful gap: most risk stratification tools treat insulin resistance and cellular aging as separate silos. Anchoring them together in a single composite index aligns with emerging evidence that inflammaging and metabolic dysregulation share overlapping biological pathways — including mitochondrial dysfunction and chronic low-grade inflammation — that together accelerate atherosclerosis, diabetes, and stroke. The cohort is large and longitudinal, and multi-state modelling captures disease transitions rather than just incidence, which is methodologically sophisticated. Key limitations include the Chinese middle-aged-and-older population, limiting generalizability, and reliance on observational data precluding causal inference. TyG is a surrogate, not a direct insulin-resistance assay. Still, if replicated in diverse cohorts, a combined TyG-BA screening tool could meaningfully refine preventive cardiovascular strategies — an incrementally important, potentially practice-shaping finding.
