Recovery of Birth WeightzScore Within 2 Years of Diagnosis Is Positively Associated With Pulmonary Status at 6 Years of Age in Children With Cystic Fibrosis

Abstract

Objective-We recently reported that 60% of newly diagnosed CF children who had pancreatic insufficiency (PI) responded to treatment initiation and achieved catch-up weight gain to a level comparable to their birth weight Z-score within 2 years of diagnosis ("responders"), while the remaining 40% failed to do so ("non-responders"). The present study examined the impact of this early weight recovery on subsequent growth pattern and pulmonary status at age 6 years.Patients and Methods-Sixty-three children with CF who had PI but no meconium ileus, and were enrolled in the Wisconsin CF Neonatal Screening Project, were studied. "Responders" were defined by a recovery of weight Z-score comparable to that at birth within 2 years of diagnosis. During ages 2-6, growth was evaluated with the combination of height and body mass index. Pulmonary status was evaluated by symptoms, spirometry, quantitative chest radiography and respiratory microbiology.Results-The majority (71%) of the responders maintained their early weight recovery through age 6 years while only 32% of the non-responders achieved substantial growth improvement during age 2 to 6 years. Proportionately fewer responders reported cough symptoms (10% daytime cough, p =0.02; 22% nighttime cough, p=0.05) compared to non-responders (41% daytime cough, 45% nighttime cough) at age 6. Percent predicted FEV 1 (%FEV 1 ) at age 6 was 11% higher in responders (99.5 ± 13.9%) compared to non-responders (88.3 ± 18.5%), p = 0.015. Responders had significantly better Brasfield (20.1 ± 1.4, p = 0.01) and Wisconsin chest radiographic scores (8.3 ± 3.3, p = 0.04) compared to non-responders (Brasfield 18.9 ± 1.8, Wisconsin 12.3 ± 8.3). Respiratory microbiology was not significantly different. Multiple regression analyses indicated that the positive association between responder and %FEV 1 at age 6 years remained statistically significant after controlling for infections with Pseudomonas aeruginosa and Staphlococcus aureus and chest radiographic scores. Growth patterns during 2-6 years of age were not associated with pulmonary measures at age 6. A complete list of the researchers who have participated in this project is provided in the acknowledgement. NIH Public Access Author ManuscriptPediatrics. Author manuscript; available in PMC 2010 February 1. Conclusion-CF patients with PI who achieved early growth recovery within 2 years of diagnosis had fewer cough symptoms, higher lung function and better chest radiography scores at 6 years of age. KeywordsCystic Fibrosis; Growth; Malnutrition; Height; Weight; Body mass index; Pulmonary function; Chest radiograph; Newborn screening Cystic fibrosis (CF) is a life-threatening, genetic disorder that is generally characterized by intestinal malabsorption, impaired growth and lung disease. Malnutrition is prevalent (1-5), as indicated by the observation that nearly half of newly diagnosed CF children have a height or weight below the 5 th percentile (3), and is associated with poor clinical outcomes (1,6-10). Therefore, optimizing nutr...

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