The triglyceride-glucose (TyG) index as an emerging biomarker for delirium: A systematic review and meta-analysis

Delirium is a common and serious neuropsychiatric complication among acutely ill and surgical patients. Insulin resistance has been implicated in delirium vulnerability. The triglyceride-glucose (TyG) index, a simple surrogate marker of insulin resistance, has shown relevance in metabolic and neurological disorders, but its association with delirium remains unclear.

Following PRISMA guidelines, we performed a systematic review and meta-analysis of observational studies identified in PubMed, Embase, and Web of Science up to December 2025. Random-effects models were used to estimate pooled odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup and sensitivity analyses evaluated robustness, and study quality was assessed using the QUIPS tool.

Eight cohort studies including 25,462 participants (9739 delirium cases) were analyzed. Elevated TyG index was associated with an increased risk of delirium (pooled OR = 1.37, 95% CI: 1.29-1.46, p < 0.001), and each unit increase in TyG corresponded to a 29% higher risk (OR = 1.29, 95% CI: 1.21-1.37), with negligible heterogeneity (I² = 0%). The association remained consistent across subgroups defined by surgical status, metabolic conditions, and demographic factors, while a modestly stronger effect was observed in patients with heart failure (p for subgroup difference = 0.009). Sensitivity analyses confirmed the stability of results, and no publication bias was detected.

Elevated TyG index was associated with delirium risk across the included retrospective cohorts. As an accessible biomarker, TyG may facilitate early identification of patients at risk, reflecting the contribution of insulin resistance-related metabolic dysfunction to delirium pathogenesis.