BackgroundThe Triglyceride and Glucose (TyG) index has been found to have a strong correlation with the recurrence of acute ischemic stroke (AIS) and poor patient outcomes. Nevertheless, the relationship between the TyG index and early neurological deterioration (END) has not been fully explored. Therefore, the present study aims to investigate the potential association between the TyG index and END.MethodsA retrospective analysis of 2129 patients diagnosed with AIS between January 2019 and December 2022 at the Second Affiliated Hospital of Harbin Medical University. Patients were divided into END and non-END groups based on changes in National Institutes of Health Stroke Scale scores within 7 days of admission, and the differences in the indicators between the two groups were examined using univariate analysis. The patients were then divided into three groups based on the tertile of the TyG index (T1: TyG index < 8.662; T2: 8.662 ≤ TyG index < 9.401; T3: TyG index ≥ 9.401), and logistic regression analysis was used to examine the association between the TyG index and END. Finally, the predictive ability of the TyG index was evaluated using the receiver operating characteristic (ROC) curve.ResultsA total of 724 patients experienced END. The results of the analysis showed that the TyG index was significantly higher in the END group compared to the non-END group. Furthermore, the TyG index was found to be an independent risk factor for the development of END (OR, 1.561; 95% 1.166–2.090,P= 0.003). After adjusting for confounders, the risk of END was 3.953 (95% CI 2.793–5.595;P< 0.001) and 5.906 (95% CI 3.676–9.488;P< 0.001) times higher in the T2 and T3 groups, respectively, in contrast to the T1 group. The area under the ROC curve of the TyG index was 0.711 (0.688–0.733), indicating an excellent predictive indicator.ConclusionsOur study uncovered that higher TyG index levels were associated with END development in AIS patients.