Respiratory Medicine, cilt.258, 2026 (SCI-Expanded, Scopus)
Background: Malnutrition is a recognized but insufficiently investigated concern in children with childhood interstitial lung diseases (chILD). The relationship between nutritional status and pulmonary function in this population remains poorly understood. This study aimed to evaluate the frequency and impact of malnutrition in chILD and to identify associated clinical factors. Methods: We analyzed baseline and follow-up data from the chILD-EU registry, including anthropometric measurements, disease severity scores, pulmonary function tests, and treatment information. Malnutrition was defined as a weight-for-age (WFA) z-score < −2. Multivariable linear regression models were used to assess the association between malnutrition and lung function after adjustment for potential confounders. Longitudinal mixed-effects models were applied to evaluate the relationship between time-varying nutritional status and lung function over time. Results: A total of 3351 visits from 766 children were analyzed. At baseline, 38.9% of children were malnourished. Children with malnutrition had significantly lower lung function compared with those without malnutrition (both p < 0.001). In multivariable analyses adjusting for age, sex, prematurity, diagnostic category, and disease severity, malnutrition remained independently associated with reduced lung function (zFEV1 β = −0.83, p = 0.007; zFVC β = −1.35, p < 0.001). In longitudinal mixed-effects models including baseline and follow-up visits, improvements in WFA z-scores were associated with improved lung function over time (zFEV1 β = 0.33, p < 0.001; zFVC β = 0.37, p < 0.001). Conclusion: Malnutrition is common among children with chILD and is independently associated with impaired lung function and greater disease severity. Improvements in nutritional status are associated with improved pulmonary outcomes during follow-up, highlighting the importance of routine nutritional monitoring and multidisciplinary care.