Abstract
BACKGROUND: Asthma prevalence is associated with metabolic score for visceral fat (METS-VF) and weight-adjusted waist index (WWI). Nonetheless, whether their associations with all-cause mortality differ in magnitude or predictive accuracy, especially in asthma patients, has not been empirically established. METHODS: Our study examines data derived from the National Health and Nutrition Examination Survey (NHANES) database, spanning the years 1999 to 2018, and encompasses a sample of 1,260 adult asthma patients. To examine the relationship between METS-VF and WWI in predicting all-cause mortality among asthma patients, we utilized multivariable Cox proportional hazards regression analysis, Kaplan-Meier survival curves, restricted cubic spline models, as well as receiver operating characteristic (ROC) curves. RESULTS: Within a median follow-up duration of 95 months, 188 all-cause deaths were recorded. An increase of 1 unit in METS-VF was associated with a hazard ratio (HR) of 2.01 for all-cause mortality, whereas for WWI, the HR was 1.46. Additionally, restricted cubic spline analyses showed no statistically significant non-linear relationships between the two indicators and all-cause mortality. In weighted multivariable Cox regression models, HRs were notably elevated in the highest METS-VF and WWI groups compared to the reference groups. The time-dependent ROC curves demonstrated that WWI had slightly higher AUC values than METS-VF in predicting all-cause mortality (5-year: 0.829 vs. 0.819; 10-year: 0.861 vs. 0.860; 15-year: 0.866 vs. 0.864). CONCLUSION: Elevated levels of METS-VF and WWI are positively associated with an increased risk of all-cause mortality among asthma patients. Additionally, METS-VF exhibited relatively lower discriminatory ability for predicting all-cause mortality compared to WWI. Notably, this study did not account for potential confounding by asthma severity markers (e.g., lung function, medication use), which may influence mortality risk. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12890-025-03951-z.