Evidence of diminished FEV1 and FVC in 6-year-olds followed in the European cystic fibrosis patient registry, 2007-2009

BackgroundMany infants with cystic fibrosis (CF) exhibit airway inflammation, gas trapping, bronchiectasis, and/or reduced flow, but by age 6 years have forced vital capacities (FVC) and expiratory volumes in 1 second (FEV1) within the variability range of the normal population. We sought evidence of diminished FVC and FEV1 in 6-year-olds with CF.MethodsGLI 2012 FVC and FEV1 Z-scores for 6-year-olds from the European CF Patient Registry were plotted against theoretical values from the Normal distribution.ResultsMean FVC and FEV1 Z-scores for 681 patients (322 females) were − 0.43 (SD = 1.41) and − 0.65 (1.40). Z-scores were consistently lower than expected for the normative population by quantile-quantile plot.ConclusionsDiminished FEV1, and to a lesser extent FVC, is found in a large majority of this population, consistent with an established body of evidence that loss of lung function begins early in life for most, if not all, children with CF.