Comparison of growth status of patients with cystic fibrosis between the United States and Canada

Background: Differences in growth status of patients with cystic fibrosis ( CF) between the United States and Canada were reported in the 1980s based o n analysis of data from 2 regional CF centers. Objective: We evaluated the current growth status of the entire CF populati on in the United States and Canada in view of recent advances in the treatm ent of CF. Design: Growth data from the 1992-1994 CF Patient Registries were analyzed. Results: Mean height and weight were at approximately the 30th percentile f or children with CF in the United States. Mean height and weight were 4-5 p ercentiles higher in children with CF in Canada than in those in the United States (P < 0.01), but percentages of ideal weight (104%) were similar in both populations. In adults with CF, mean height was similar at the 37th pe r centile; however, weight (26th compared with the 21st percentiles) and pe rcentage of ideal weight (93% compared with 90%) were significantly higher in Canada than in the United States. Differences related to sex and age wer e similar in both countries for all indexes, which showed a high prevalence of underweight in infants and in older patients, but little sex discrepanc y. Conclusion: We observed substantially smaller differences in the growth ind exes of CF patients between the United States and Canada compared with resu lts from the 1980s. These findings reflect significant improvements in the nutritional status of US patients in recent years. However, caution is requ ired in the direct comparison of mean percentiles from reports using differ ent growth standards because there are systematic differences in growth sta ndards, which affect, in particular, the comparison of growth in males and females.