The Triglyceride-Glucose Index: A Cost-Effective Biomarker for Early Detection of Insulin Resistance in Autosomal Dominant Polycystic Kidney Disease

Objective: Autosomal dominant polycystic kidney disease (ADPKD) is a common hereditary cause of end-stage renal disease, often associated with metabolic disorders, including insulin resistance and diabetes mellitus (DM). The triglyceride-glucose (TyG) index has emerged as a cost-effective biomarker for predicting insulin resistance and metabolic dysfunction. This study evaluates the role of the TyG index in predicting DM development in ADPKD patients. Methods: A retrospective analysis was conducted on 156 ADPKD patients followed at the Nephrology Clinic of Dokuz Eylül University since 2000. Patients with pre-existing DM, impaired fasting glucose, or undergoing lipid-lowering therapy were excluded. Demographic and laboratory data, including the annual TyG index, were recorded and compared between patients who developed DM (n=18) and those who did not (n=138). The TyG index was calculated using the formula based on fasting triglyceride levels and fasting glucose levels. Statistical analyses included repeated measures analysis of variance and chi-square tests, with a significance threshold of p<0.05. Results: Among the cohort, 11.5% developed DM during follow-up. The TyG index was significantly higher in the DM group than in non-DM patients (p<0.05). Over time, the TyG index in the DM group showed a progressive increase, even before the detection of hyperglycemia (p<0.05). Conclusion: The TyG index is a valuable, cost-effective tool for predicting DM in ADPKD patients. Its ability to detect diabetes risk before hyperglycemia highlights its potential for early intervention strategies. Prospective studies are needed to validate these findings and explore the role of the TyG index in clinical practice.