A six-month study of growth and energy expenditure in children with cysticfibrosis taking a pulmonary inhalation medication (rhDNase)

Objective: To characterize the effects of recombinant human deoxyribonuclea se (rhDNase) on growth velocity, body composition, resting energy expenditu re (REE) and food intake in children with cystic fibrosis (CF). Methods: A prospective, six-month pilot study was conducted in twenty-one s ubjects with CF (twelve male, nine female, ages 11.5+/-3.1 years) measured at baseline, two and six months post-baseline. Repeated measures ANOVA was used to examine the change in variables across time. Results: The majority (75%) of subjects had minimal lung disease at baselin e (FEV1: 80%-119% predicted). As expected for growing children, weight and height gains (1.6 kg and 2.5 cm) were observed between baseline and six mon ths (p=0.0001). No change was observed in weight z-scores from six months p rior to initiation of rhDNase therapy to six months post, though a signific ant decline (p=0.049) in Ht z-score was observed over this twelve-month per iod. Triceps skinfolds and mid-arm muscle circumference increased from base line to six months (p<0.01); respective z-scores remained stable. Energy in take remained constant during the period it was studied from baseline to tw o months of therapy: 120%+/-27% RDA. REE, though slightly elevated compared to healthy children (baseline 106%+/-8% predicted), remained stable throug hout the study and at a level which may be expected for children with minim al lung disease. A trend (p=0.057) towards a decrease in the number of subj ects requiring hospitalization for pulmonary exacerbations during the trial period was observed. Conclusions: In summary, these pilot data from younger children with milder CF-related lung disease do not confirm anecdotal reports of improved rate of weight gain, caloric intake or decreases in the elevated REE. Future res earch might focus on documentation of the possible nutritional effects of r hDNase in clinical trials of children with more severe lung disease.