Association between nutritional status and clinical characteristics in nontuberculous mycobacterial pulmonary disease: preliminary results from the NTM-KOREA cohort

BACKGROUND: Evidence on the association between nutritional status and clinical characteristics in nontuberculous mycobacterial pulmonary disease (NTM-PD) remains limited. We investigated this association and its impact on longitudinal outcomes in a nationwide cohort. METHODS: We analysed 627 patients from the NTM-KOREA cohort study who had initiated antibiotic therapy for NTM-PD. Baseline nutritional status was assessed using the Prognostic Nutritional Index (PNI) and Mini Nutritional Assessment Short Form (MNA-SF) tools. Clinical characteristics, physical function, and health-related quality of life (HRQOL) using Quality of Life Questionnaire–Bronchiectasis (QOL-B) were evaluated. Longitudinal analyses were performed at 6 and 12 months after therapy initiation. RESULTS: In the baseline anlysis group (N = 627; mean age: 64.3 ± 9.7 years; females: 73.7%), 112 (17.9%) patients were classified as malnourished according to the PNI, and MNA-SF identified 319 (50.9%) patients at risk and 40 (6.4%) as malnourished. Multivariable regression analysis revealed that the PNI-defined malnutrition group was associated with increased odds (odds ratio [95% confidence interval]) of having dyspnoea (2.37 [1.34 to 4.11]), acid-fast bacilli smear positivity (2.26 [1.44 to 3.57]), and cavitary lesions (2.03 [1.25 to 3.37]). This group was also associated with higher BACES (body mass index, age, cavity, erythrocyte sedimentation rate, and sex) scores (β = 0.9), shorter 6-min walking distance (β = -42.1 m), and lower QOL-B scores across physical functioning (β = -10.6), role functioning (β = -7.4), and respiratory symptoms (β = -8.0) (all P < 0.001). In the longitudinal anlysis group (n = 457), poor nutritional status reduced the likelihood of 6-month respiratory symptom improvement (0.44 [0.22 to 0.87]). In the treatment outcome analysis group (n = 119), MNA-defined malnutrition was significantly associated with an increased risk of premature treatment discontinuation within 1 year (26.41 [2.82 to 633.89]). CONCLUSIONS: Baseline nutritional status was closely associated with disease severity and HRQOL in NTM-PD. Preliminary longitudinal data suggested that malnutrition may negatively impact symptomatic improvement and treatment adherence, highlighting the need for routine nutritional assessment. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT03934034, Registration date May 1, 2019.