Association Between Triglyceride-Glucose Index And Risk Of Acute Kidney Injury After Cardiac Surgery

Background and objective:Acute kidney injury(AKI)is a syndrome characterized by rapid loss of renal excretory function and is diagnosed by accumulation of nitrogen metabolism end products(urea and creatinine)or decreased urine output or both.AKI is one of the most dangerous factors for death after cardiac surgery and has a significant impact on patients’ prognosis.Triglyceride-glucose index(TyG),a new index consisting of a combination of fasting glucose and triglycerides,has been shown to be a simple and reliable biological surrogate for insulin resistance(IR).However,researches on the association between TyG index and AKI after cardiac surgery is still relatively scarce.Therefore,the aim of this study was to investigate the asociation between preoperative TyG index and postoperative AKI in patients undergoing cardiac surgery.Methods:This is a single-center retrospective cohort study that collected clinical data from 1025 patients who underwent cardiac surgery at Southern Hospital of Southern Medical University from March 2019 to September 2022.The incidence and severity of AKI were diagnosed by KDIGO criteria.And the correlation of TyG index with the incidence of postoperative AKI and its severity was compared.The diagnostic value of the TyG index and other metabolic indices for postoperative AKI after cardiac surgery was compared using ROC analysis.Finally,generalized additive model(GAM),subgroup analysis,and interaction test were used to verify the robustness of the results.Results:A total of 1025 patients were included in this study,and the incidence of postoperative AKI after cardiac surgery was 33.3%.The incidence of postoperative AKI was higher and more severe with increasing TyG index.Similarly,patients who developed AKI had a higher level of preoperative TyG index distribution compared to those without postoperative AKI.After adjusting for risk factors such as age,gender,BMI,preoperative cardiac and renal function,emergency surgery,different types of surgery,and extracorporeal circulation surgery,logistic regression analysis showed that higher preoperative TyG index was a risk factor for the development of AKI after cardiac surgery(OR=1.34,95%CI 1.05-1.71,p=0.017);compared with the lowest quartile of TyG index,the risk of AKI was 1.56 times higher in the highest quartile(OR=1.56,95%CI 1.02-2.37,p=0.039).In addition,ROC curves analysis showed that TyG index and other metabolic indices(fasting glucose,glycated hemoglobin,and triglycerides)had diagnostic value for AKI,and TyG index had the largest AUC value.Subgroup analysis resulted in a more significant correlation between the detection of TyG index and the risk of postoperative AKI in those older than 65 years.Conclusion:This study shows that a higher TyG index is positively associated with an increased risk of postoperative AKI in patients undergoing cardiac surgery and is an independent risk factor for postoperative AKI.And TyG index has potential diagnostic value for postoperative AKI and may play a key role in risk stratification for AKI in clinical practice.