Background Many patients with cystic fibrosis are malnourished at the
time of diagnosis, Whether newborn screening and early treatment may p
revent the development of a nutritional deficiency is not known. Metho
ds We compared the nutritional status of patients with cystic fibrosis
identified by neonatal screening or by standard diagnostic methods. A
total of 650,341 newborn infants were screened by measuring immunorea
ctive trypsinogen on dried blood spots (from April 1985 through June 1
991) or by combining the trypsinogen test with DNA analysis (from July
1991 through June 1994). Of 325,171 infants assigned to an early-diag
nosis group, cystic fibrosis was diagnosed in 74 infants, including 5
with negative screening tests. Excluding infants with meconium ileus,
we evaluated nutritional status for up to 10 years by anthropometric a
nd biochemical methods in 56 of the infants who received an early diag
nosis and in 40 of the infants in whom the diagnosis was made by stand
ard methods (the control group). Pancreatic insufficiency was managed
with nutritional interventions that included high-calorie diets, pancr
eatic-enzyme therapy, and fat-soluble vitamin supplements. Results The
diagnosis of cystic fibrosis was confirmed by a positive sweat test a
t a younger age in the early-diagnosis group than in the control group
(mean age, 12 vs. 72 weeks). At the time of diagnosis, the early-diag
nosis group had significantly higher height and weight percentiles and
a higher head-circumference percentile (52nd, vs. 32nd in the control
group; P=0.003). The early-diagnosis group also had significantly hig
her anthropometric indexes during the follow-up period, especially the
children with pancreatic insufficiency and those who were homozygous
for the Delta F508 mutation. Conclusions Neonatal screening provides t
he opportunity to prevent malnutrition in infants with cystic fibrosis
. (C) 1997, Massachusetts Medical Society.