ABSTRACT Rationale Primary ciliary dyskinesia (PCD) is a phenotypically diverse disease; the impact of nutritional status on clinical trajectories in patients with PCD is not well defined. The aim of this study is to examine the impact of malnutrition on lung function in a pediatric cohort of patients with PCD. Methods This was a retrospective cohort study of pediatric patients with a confirmed diagnosis of PCD at the Hospital for Sick Children in Toronto, Canada between 2000 and 2022. Undernutrition was defined as a BMI‐ or weight‐for‐age z‐score < ‐1. Mixed effects linear regression models were used to assess the effect of undernutrition on FEV 1 z‐score (zFEV 1 ) over time. Results Ninety‐six patients with a median age at diagnosis of 7 years (IQR 3, 12) were included. Mean (SD) BMI‐for‐age z‐score at first encounter was 0.15 (1.51), and weight‐for‐age z‐score 0.00 (1.42). On a per visit basis, a BMIz or WFAz of < ‐1 was associated with a 0.21 lower zFEV 1 (95% CI −0.35, −0.08; p = 0.002). Patients who had at least one encounter with undernutrition had a zFEV 1 1.30 lower overall than patients who were consistently well‐nourished (95% CI: −1.72, −0.88; p < 0.001). There was no significant difference in the rate of FEV 1 decline or time to next exacerbation between the two groups. Conclusions In pediatric patients with PCD, undernutrition was associated with a significantly lower FEV 1 , both at individual encounters and when compared to consistently well‐nourished individuals. There was no significant difference in the rate of FEV 1 decline in patients who were undernourished.
McCoy et al. (Wed,) studied this question.