BACKGROUND: Metabolic dysfunction is associated with respiratory diseases, and the triglyceride-glucose (TyG) index is an important indicator of metabolic dysfunction. OBJECTIVES: The purpose of this study was to explore the possible relationship between TyG and asthma exacerbation, while also investigating potential subgroup differences in this relationship. METHODS: Data from the 2009-2018 National Health and Nutrition Examination Survey (NHANES) were included. Multifactorial logistic regression, subgroup analysis, smoothed curve fitting, and threshold effect analysis models were used to explore the relationship between TyG and asthma exacerbations. RESULTS: A total of 964 participants were included in the analysis (34.13 % male, 65.87 % female, 45.4 % Non-Hispanic White, 25.3 % Non-Hispanic Black), with a mean age of 50.57 ± 17.32 years. We found a nonlinear positive relationship between TyG and asthma exacerbation, which was maintained in all three models. In the fully adjusted model, the risk of asthma exacerbation increased by 25 % with each unit increase in the patient's TyG level (OR:1.25, 95 %CI: 1.21-1.30). Subgroup analysis showed significant associations between TyG and asthma exacerbations among females, as well as in individuals aged 20-59, body mass index (BMI) <
25 or BMI≥30. Furthermore, a U-shaped relationship between TyG and asthma exacerbation was identified in males using smoothed curve fitting, with an inflection point at the TyG level of 9.15. CONCLUSIONS: We found a nonlinear positive association between TyG and asthma exacerbation. Our study highlights the potential clinical value of TyG in managing asthma exacerbations, particularly emphasizing the need for gender-specific risk management strategies.