Summary background: There is very limited information on how the risk of persistent asthma in recurrent wheezing (RW) infants modifies their lung function early in life. The aim of this study is to compare lung function of RW infants and young children with a positive or negative asthma predictive index (API), an index previously used to anticipate asthma persistence into childhood and adolescence.
Methods: Two groups of RW infants and young children were recruited in two centres in Spain (Palma de Mallorca and Murcia). Lung function was measured according to the thoracho-abdominal compression technique (RCT), and values of the maximal flow at functional residual capacity (V'FRC) were expressed as Z-scores. Other variables included in the study, as independent factors, were: gender, age, length, weight, and parental smoking habits together with information regarding API.
Results: Expressed as mean +/- SD, API+ RW infants (n = 50; age in months 11.9 +/- 4.9) had a lower V'FRC Z-score than API- RW ones (n = 41; age in months 12.3 +/- 6.2; -2.01 +/- 0.79 vs. -1.64 +/- 0.77, P = 0.026, respectively). Centre and tobacco exposition did not have an effect on lung function.
Conclusion: Among RW infants and young children, those having a positive API have a significant lower lung function as measured by V'FRC at an early age.