Abstract
BACKGROUND: Changes in systemic inflammation, nutritional status and serum vitamin D level are important characteristics of asthma. However, role and importance of nutritional inflammatory indicators or serum vitamin D concentrations in predicting the prognosis of asthma remain unclear. The advanced lung cancer inflammation index (ALI), based on body mass index (BMI), serum albumin and neutrophil-lymphocyte ratio (NLR), is a comprehensive index to assess systemic inflammation and nutrition. This study aimed to evaluate their independent and combined predictive value of mortality in asthma patients. METHODS: This study analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2001-2018. Cox regression analysis was used to assess the independent or joint effect of ALI and serum vitamin D on mortality risks of asthma. Receiver operator characteristic curve analysis was used to compare the prognostic ability of ALI with its component factors, including NLR, albumin, neutrophil, lymphocyte and BMI. RESULTS: A total of 2870 eligible asthma patients were included. After adjustment, higher ALI correlated significantly with reduced all-cause and respiratory disease mortality (adjusted hazard ratio [aHR] = 0.64 and 0.34; P < 0.05). Meanwhile, vitamin D deficiency correlated significantly with increased all-cause and respiratory disease mortality (aHR = 2.06 and 2.73; P < 0.05). The area under the curve of ALI in predicting 1-year, 5-year or 10-year all-cause mortality surpassed that of its five component indices. Joint analyses showed that individuals with higher levels of ALI and vitamin D had the lowest risks of all-cause and respiratory disease mortality (aHR = 0.31 and 0.17; P < 0.05). CONCLUSIONS: ALI and serum vitamin D are robust independent and combined predictors of mortality in asthma patients. ALI offers superior predictive capability over its components, and sufficient vitamin D levels are beneficial for survival outcomes. The synergistic effect of high ALI and adequate vitamin D highlights the benefit of integrating both metrics into clinical practice for enhanced prognostic accuracy.