Chronic kidney disease (CKD) is the eleventh leading cause of death globally, and the burden of disease and economic impact caused by it is increasing rapidly. Its disability and mortality rates have exhibited the highest increase among all chronic diseases. Insulin resistance (IR) and obesity are closely associated with the onset and progression, and triglyceride-glucose (TyG) index can serve as a substitute indicator for IR. Nevertheless, the exact relationship between the TyG index and the development of CKD remains to be fully elucidated.

Through a cohort study, we aim to investigate the relationship between triglyceride-glucose (TyG) index and its combination with obesity indices in relation to the occurrence of CKD.

This retrospective cohort study selected 4 921 adult participants who underwent annual physical examinations at the Sichuan Provincial People's Hospital Health Management & Physical Examination from January 2015 to November 2022, according to specific inclusion and exclusion criteria. The study cohort was categorized into four groups based on quartiles of the baseline triglyceride-glucose (TyG) index: Q1 (5.43-6.66) , Q2 (6.67-7.04) , Q3 (7.05-7.43) , and Q4 (7.43-9.97) , with sample sizes of 1 230, 1 231, 1 230 and 1 230, respeciyvely Obesity-related indices including waist circumference (WC) , BMI, and waist-to-hip ratio (WHR) , were combined with the TyG index to form TyG-WC, TyG-BMI, and TyG-WHR indices. Based on the quartiles of the baseline TyG-WC index, the study subjects were divided into 4 groups, Q1 (204.49-523.14) , Q2 (523.15-593.21) , Q3 (593.22-657.16) , and Q4 (657.17-992.75) , with sample sizes of 1 230, 1 232, 1 229 and 1 230, respectively. Based on the quartiles of the baseline TyG-BMI index, the study subjects were divided into 4 groups, Q1 (92.43-149.16) , Q2 (149.17-168.43) , Q3 (168.49-188.92) , and Q4 (88.93-306.64) , with sample sizes of 1 228, 1 231, 1 232 and 1 230, respectively. Based on the quartiles of the baseline TyG-WHR index, the study subjects were divided into 4 groups, Q1 (2.76-5.66) , Q2 (5.67-6.26) , Q3 (6.27-6.83) , and Q4 (6.84-9.67) , with sample sizes of 1 230, 1 230, 1 231 and 1 230, respectively. The relationship between the TyG index and its combination with obesity indices and the incidence risk of CKD was examined by a Cox proportional hazards model, while a restricted cubic spline regression (RCS) was used to assess dose-response relationships.

At the end of follow-up, there were 139 new cases of CKD in the study cohort, with an incidence rate of 2.8%. After accounting for potential confounding factors, the results showed that compared to the TyG index Q1 group, the TyG index Q4 group exhibited a significantly elevated risk of CKD incidence (HR=1.756, 95%CI=1.010-3.054) . Compared to the TyG-WC index Q1 group, the TyG-WC index Q4 group demonstrated a significantly higher risk of CKD incidence (HR=2.532, 95%CI=1.210-5.296) , with P<0.05. There was a non-linear dose-response relationship between the TyG index and the risk of CKD incidence (P_nonlinearity=0.048) , with higher TyG index values (>6.93) associated with a greater risk of CKD incidence. The TyG-WC index had a linear dose-response relationship with the risk of CKD incidence (P_nonlinearity=0.078) , with an increasing trend of CKD incidence risk with increasing TyG-WC index values.

Both TyG and TyG-WC are risk factors for CKD, controlling for TyG and WC can effectively prevent and manage CKD, this finding holds great importance for the prevention and treatment of CKD.