Triglyceride–Glucose Index and Acute Kidney Injury: A Systematic Review and Meta-Analysis

Background: The triglyceride–glucose (TyG) index, a surrogate marker of insulin resistance, has been increasingly associated with adverse cardiometabolic outcomes. However, its relationship with acute kidney injury (AKI) across clinical settings has not been comprehensively synthesized. We performed a systematic review and meta-analysis to evaluate the association between the TyG index and AKI risk. Methods: PubMed, Embase, and Web of Science were searched through February 2026 for observational studies reporting adjusted associations between TyG and AKI. Random-effects models were used to pool categorical and continuous effect estimates. Dose–response analyses and subgroup assessments were conducted to explore consistency. Diagnostic performance was summarized when available. Results: Thirty studies involving 518,677 participants were included. Compared with the lowest-TyG category, the highest-TyG category was associated with significantly increased AKI risk (pooled OR = 1.95, 95% CI 1.66–2.28; I2 = 72.7%). Associations were most consistently observed in cardiovascular disease cohorts (pooled OR = 1.86, 95% CI 1.44–2.40) and remained directionally similar across other clinical settings without significant subgroup interactions. Each 1-unit increment in TyG index was associated with higher AKI risk (OR = 1.48, 95% CI 1.30–1.69), and time-to-event analyses yielded concordant results (HR = 1.38, 95% CI 1.14–1.65). A significant non-linear dose–response association was observed (p < 0.001). The TyG index showed moderate discrimination (AUC = 0.74), with findings remaining robust in sensitivity analyses. Conclusions: Current evidence supports TyG primarily as a complementary metabolic risk marker rather than a substitute for established AKI diagnostic or prediction tools. TyG may serve as a practical marker for metabolic risk stratification in patients at risk of AKI.