Results
We enrolled 57 patients with a mean age of 8.4 years, 59.6% were male. We identified 3 groups of children according with the presence of RI. Group 1 corresponded to 17 (29.8%) patients without RI, group 2 to 17 (29.8%) children in whom RI did not persist after the bronchodilator test, and group 3 to 23 (40.4%) children who had RI before and after the bronchodilator test. The demographic characteristics of the three groups were shown in Table 1. Groups 2 and 3 had lower birth weight and gestational age than group 1; although it was significantly between group 2 vs. 1. No significant differences were found in history of maternal asthma, prenatal or postnatal maternal smoking among groups. Lung function measured by spirometry and IOS was more altered in groups 2 and 3 than in the group 1. VEF1 and FEF25-75 were significantly lower in groups 2 and 3 than in group 1, and FVC was lower in the group 3 vs 1. In the IOS, R5, AX, Fres and DR5-R20 were significantly lower in the group 1 vs. 3. Also, R5 and DR5-R20 were lower in the group 2 vs. 3. In contrast, X5c was significantly higher in the groups 1 and 2 vs. 3, and in the group 2 vs. 3. Finally, RBD in X5c and D5-20 were significant lower in the group 1 vs. 2, and in group 2 vs 3 (Table 2).