Lung function and nutritional status in children with cystic fibrosis and primary ciliary dyskinesia

Abstract

Introduction: Cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) both cause recurrent pulmonary infections resulting in bronchiectasis. CF is considered the more severe condition. Nutritional status is fundamental to outcome in CF but there is little evidence about its importance in PCD.

Aim: To compare BMI and lung function of pancreatic sufficient (PS) and insufficient (PI) CF children to those with PCD.

Methods: Cross sectional data (2015) from 204 CF (189 PI, 15 PS) and 46 PCD children, obtained at annual review at our Paediatric Respiratory Centre were compared.

Results: Age, sex and mean BMI centile were comparable across the three groups. Mean age (SD) at diagnosis was significantly older in the PCD compared to the PI-CF cohort (4.8yrs (4.6) vs 0.6yrs (1.3) P<0.001). While FEV₁% did not vary significantly with BMI centile in PS-CF, a lower BMI centile was associated with a lower FEV₁% in both PI-CF and PCD cohorts, even when adjusted by age. FEV₁ declined similarly in the PS-CF and PCD groups with increasing age although the rate of decline was greater in the PI-CF cohort. Of note, the mean (SD) FEV₁% was significantly lower in the PCD cohort than both PI-CF and PS-CF children (73.8% (19.4), 84.9% (21.2), 96.1% (15.9) P<0.05 respectively).

Conclusion: Similar to PI-CF, a lower BMI centile was associated with a lower FEV₁% in our PCD cohort. Whilst a greater decline in FEV₁% with increasing age was observed in the PI-CF patients, the mean FEV₁% in the PCD patients was significantly lower and they were significantly older at diagnosis. Optimising nutritional status and earlier diagnosis might be of importance in improving lung function amongst PCD patients.