Infants with flow limitation at 4 weeks: outcome at 6 and 11 years.
Within a longitudinal study of lung function in 243 infants, we identified a group of 23 individuals with flow limitation in tidal expiration. In infancy, flow-limited children have reduced lung function and increased airway responsiveness (AR), and at 2 years of age they are diagnosed with asthma more frequently. We hypothesized that these observations would persist throughout childhood. Data from ages 3 to 11 years were analyzed. Only at 4 years of age did the flow-limited group have increased wheeze compared with other cohort members (odds ratio, 4.25; 95% confidence interval [CI], 1.11 to 16.2; p = 0.04; n = 114). At 6 years of age, 117 cohort members were seen. The flow-limited group (n = 14) had greater AR (p = 0.009) and reduced mean FEV(1) (131 ml; 95% CI, 16 to 246; p = 0.03) and FEF(25-75) (0.28 L/second; 95% CI, 0.05 to 0.52; p = 0.02). At 11 years of age, 183 children were seen and the flow-limited group (n = 18) had greater AR (p = 0.02) and a trend toward reduced mean FEF(25-75) (0.24 L/second; 95% CI, -0.02 to 0.49; p = 0.08). Atopy and parental asthma were not increased in the flow-limited group. We suggest that the physiologic abnormality that causes flow limitation in early infancy may identify an at-risk group, different from asthma, who have reduced lung function and increased airway responsiveness in later life.
Turner
Stephen W
SW
University Department of Paediatrics, Princess Margaret Hospital for Children, Perth, Western Australia, Australia.
Palmer
Lyle J
LJ
Rye
Peter J
PJ
Gibson
Neil A
NA
Judge
Parveenjeet K
PK
Young
Sally
S
Landau
Louis I
LI
Le Souëf
Peter N
PN
D002648:Child; D004804:Eosinophils; D005540:Forced Expiratory Flow Rates; D005541:Forced Expiratory Volume; D006801:Humans; D007231:Infant, Newborn; D007958:Leukocyte Count; D008137:Longitudinal Studies; D015999:Multivariate Analysis; D012123:Pulmonary Ventilation; D012044:Regression Analysis; D012130:Respiratory Hypersensitivity / Q000453:epidemiology / Q000503:physiopathology*; D018709:Statistics, Nonparametric; D014904:Western Australia / Q000453:epidemiology