Abstract
BACKGROUND: Nutritional status has been increasingly recognized as an important determinant of outcomes in nontuberculous mycobacterial pulmonary disease (NTM-PD), but its predictive value for sputum culture conversion remains unclear. METHODS: This retrospective cohort study included 416 patients with NTM-PD between January 2016 and September 2024. Patients were categorized based on nutritional status and sputum culture conversion. Logistic regression was used to identify independent predictors, and a combined predictive model was evaluated using ROC curves. Kaplan-Meier analysis assessed time to culture conversion. Internal validation was performed using bootstrap resampling. RESULTS: Among 416 patients, 109 (26.2%) achieved sputum culture conversion. Malnourished patients had significantly lower conversion rates. Multivariable analysis showed age (OR=1.048, 95% CI: 1.012-1.085), BMI (OR=0.746, 95% CI: 0.668-0.835), hemoglobin (OR=0.936, 95% CI: 0.906-0.967), and total protein (OR=0.920, 95% CI: 0.853-0.992) were independent predictors. The combined model demonstrated strong predictive performance (AUC=0.925, sensitivity=89.3%, specificity=78.0%). CONCLUSION: Nutritional status is significantly associated with sputum culture conversion in NTM-PD. A combined model incorporating nutritional indicators may assist in risk stratification, although further validation is required.