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

AbstractBackgroundMany infants with cystic fibrosis (CF) exhibit airway inflammation, gas trapping, bronchiectasis, and/or reduced flow, but by age 6years have forced vital capacities (FVC) and expiratory volumes in 1second (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