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

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. 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. 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). 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. ClinicalTrials.gov identifier NCT03934034, Registration date May 1, 2019.