Triglyceride-glucose index and risk of renal function decline and death-censored renal allograft loss in kidney transplant recipients

Abstract

Background: Although insulin resistance is common, its significance in kidney transplant recipients remains unclear. We explored clinical implications of the triglyceride-glucose (TyG) index as a marker for unfavorable allograft outcomes in kidney transplant recipients.

Methods: A total of 6,354 kidney transplant recipients were enrolled in a multicenter prospective cohort study between May 2014 and December 2022. The TyG index was assessed between 6 and 12 months after transplantation. We evaluated the association between the TyG index and the risk of adverse kidney outcomes.

Results: The cumulative rates of ≥50% decline in estimated glomerular filtration rate (eGFR), death-censored graft survival, and major adverse kidney events differed across TyG index quartiles, with the highest rate observed in quartile 4 (p < 0.001). TyG index quartile 4 was associated with the highest risk of death-censored graft loss after multivariable adjustment (adjusted hazard ratio, 2.13; 95% confidence interval [CI], 1.28-3.55). The risk of ≥30% decline in eGFR was 1.46 times higher (95% CI, 1.17-1.82) in quartile 4 compared with quartile 1, and the risk of ≥50% decline was 1.78 times higher (95% CI, 1.30-2.44). Quartile 4 also showed a significantly steeper decline in renal function, with an adjusted mean difference in eGFR slope of -4.72 mL/min/1.73 m2 (95% CI, -7.39 to -2.04).

Conclusion: Kidney transplant recipients with high TyG index were at increased risk of eGFR decline and graft loss, and also exhibited a more rapid deterioration in renal function. The TyG index is a useful marker for identifying individuals at high risk for adverse graft outcomes.

Keywords: Delayed graft function; Graft survival; Insulin resistance; Kidney transplantation.