PANCREATIC INSUFFICIENCY, GROWTH, AND NUTRITION IN INFANTS IDENTIFIED BY NEWBORN SCREENING AS HAVING CYSTIC-FIBROSIS

To evaluate the impact of early pancreatic insufficiently on growth and nutritional status in cystic fibrosis, we studied 49 infants identified by a newborn screening program. Pancreatic insufficiency, determined by increased 72-hour fecal fat excretion, was present in 59% (23/39) of infants at diagnosis (7.0 +/- 0.8 weeks; mean +/- SEM). Before initiation of pancreatic enzyme replacement, growth and nutritional status of pancreatic-insufficient (n = 16) and pancreatic-sufficient (n = 13) infants were compared. Pancreatic-insufficient infants gained less weight from birth to diagnosis (13.4 +/- 3.4 vs 22.3 +/- 4.0 gm/day; p = 0.05), had decreased triceps skin-fold thicknesses (4.5 +/- 0.3 vs 6.1 +/- 0.4 mm; p < 0.005), and had lower blood urea nitrogen (3.07 +/- 0.42 vs 4.62 +/- 0.65 mg/dl; p = 0.02) and albumin (2.99 +/- 0.14 vs 3.54 +/- 0.14 gm/dl; p < 0.01) levels despite higher gross calorie (154 +/- 8 vs 116 +/- 13 kcal/kg per day; p < 0.01) and protein intakes (2.81 +/- 0.21 vs 2.14 +/- 0.33 gm/kg per day; p = 0.03). Fecal nitrogen loss was correlated with fat loss (r = 0.79; p < 0.001). Fat malabsorption was present in 79% (30/38) and 92% (33/36) of infants tested at 6 months and 12 months of age, respectively, indicating that pancreatic insufficiency persists and increases in frequency throughout infancy. We conclude that pancreatic insufficiency is prevalent in young infants with cystic fibrosis and has a significant impact on growth and nutrition.