Association between triglyceride-glucose (TyG) index and diabetic foot ulcers in adult inpatients with type 2 diabetes at hospital admission

Introduction Diabetic foot ulcers (DFUs) are among the most serious complications of diabetes mellitus. Over the last years, the triglyceride-glucose (TyG) index has emerged as a surrogate marker of insulin resistance. We previously conducted a retrospective study on Albanian adult inpatients with type 2 diabetes (T2D), in which we showed that circulating triglycerides and fasting plasma glucose at hospital admission were among the most relevant independent variables associated with an increased risk of DFU in this population. Materials and methods The present dual-center, retrospective case-control study assessed the relationship between the TyG index and the presence of DFU in a cohort of 497 adult inpatients (295 males; 202 females) with T2D, who were consecutively admitted to two Hospitals during different periods between 2014 and 2023. Patients with DFUs served as cases (DFU group; n=106), while patients without DFUs served as controls (non-DFU group; n=391). Results Mean TyG index values were significantly higher in the DFU group than in the non-DFU group (5.02 ± 0.15 vs. 4.98 ± 0.09; p<0.001). Mean TyG-body mass index (BMI) index (TyG-BMI index) values were also significantly higher in the DFU group than in the non-DFU group (133.7 ± 23.5 vs. 126 ± 20.0; p=0.004). Based on the receiver operating characteristic (ROC) curve analysis, the TyG index showed a significant discriminative ability for the prediction of DFU (AUC = 0.61; 95% CI: 0.54-0.68; p<0.001), with a sensitivity of 38% and a specificity of 92% at the cut-off point of >5.08. In the multivariate logistic regression models, the TyG index was independently associated with the presence of DFU at hospital admission: odds ratio (OR) = 2.18; 95% confidence interval (CI): 1.68-2.83; p<0.0001 [model 2]; OR = 1.86; 95% CI: 1.27-2.71; p=0.001 [model 3]. Conclusions In conclusion, our study suggests that the TyG index may represent a valid prognostic biomarker among adult inpatients with T2D. Large prospective studies are needed to better clarify the predictive value of the TyG index for DFU, as well as its role as a marker of DFU severity among adult inpatients and outpatients with T2D.