Ren CL, Konstan MW, Rosenfeld M et al.; for the Investigators and Coordinators of the Epidemiologic Study of Cystic Fibrosis.
University of Rochester, Rochester, NY, USA.
Pediatr Pulmonol 2013 Oct 1; Epub ahead of print.
Paul Robinson’s review: Previous studies of non-cystic fibrosis (non-CF) children have documented associations between wheeze patterns in early life (≤6 years of age) and lung function. The TCRS (Tucson Children’s Respiratory Study) was a seminal longitudinal birth cohort studied throughout early childhood. It showed that those children with transient wheeze (within the first 3 years of life but not present at 6 years of age) had a lower lung function initially, some improvement thereafter, but a persistent lung function deficit at school entry. In contrast, those children with persistent wheeze since the early years of life were born with normal lung function, which then declined by 6 years of age (N Engl J Med 1995;332:133–8). Whether the same relationship is present in children with CF is unclear and was the focus of the present study of data from the ESCF (Epidemiological Study of CF), an observational study of CF patients in North America from 1994 to 2005. Subjects were eligible for this study if they had been reviewed by a physician during the first year of life and each subsequent year until 6 years of age, with at least one spirometry measurement at the age of 6 years or 7 years. The main outcomes of interest were lung function in CF children aged 6–8 years and, in those who also had later spirometry measures, at 8–9 years of age.
Of the 4480 children in the ESCF study who were born between 1994 and 1998, 1302 children fulfilled the inclusion criteria, of whom 833 also had spirometry data that were available at 8–9 years of age. The pattern of changes described in the TCRS birth cohort was mirrored in this CF cohort, although not all differences between groups reached statistical significance. Persistent wheeze in CF children (i.e. present during the first 3 years of life and also at aged 6 years) was associated with lower percent of predicted forced expiratory volume in 1s compared with those children who had never wheezed, with the latter group having the best lung function of the wheeze pattern groups.