Aerobic fitness is associated with lower risk of hospitalization in children with cystic fibrosis

Abstract

Children with cystic fibrosis (CF) often have to be hospitalized because of acute exacerbation of their respiratory symptoms. Given the fact that improved peak oxygen uptake (VO2peak) is positively associated with lung function and overall health in children with CF, this study examined the association between VO2peak and the need for hospitalization in a cohort of pediatric CF patients. In a 3-year study, 77 CF children with mild-to-moderately severe CF (forced expiratory volume in 1 sec [FEV1] ≥ 50%) underwent a maximal exercise test to determine VO2peak. Anthropometric, lung function and muscle strength measurements were also conducted and dates of hospitalization were recorded for the study period. Associations were then determined between the variables recorded and hospitalization by univariate and multivariate Cox proportional hazards regression analyses. VO2peak was 38.6 ± 6.7 ml kg−1 min−1 for boys and 31.9 ± 6.9 ml kg−1 min−1 for girls. In multivariate analyses, VO2peak was the only variable significantly associated with time to hospitalization (hazard ratio 0.91, P = 0.03). A significant association was detected between greater aerobic fitness, and lower risk of hospitalization. Because hospitalization due to respiratory exacerbation is a powerful prognostic factor, our findings provide further support for the importance of aerobic fitness evaluation in the management of children with mild-to-moderately severe CF.