Effects of exercise training and montelukast in children with mild asthma.

PURPOSE: Data from the general population suggest that habitual exercise decreases bronchial responsiveness, but the possible role of exercise in asthmatics is undefined. The leukotriene receptor antagonist montelukast decreases bronchial responsiveness and exercise-induced symptoms in asthmatic children. This randomized study in children with mild asthma evaluated the combined effects of aerobic training for 12 wk and montelukast or placebo on bronchial responsiveness (BHR) to methacholine, exercise-induced bronchoconstriction (EIB), inflammatory markers in exhaled breath condensate (EBC), and asthma exacerbations. METHODS: Fifty children (mean age +/- SD: 10.2 +/- 2.4 yr) with mild stable asthma were randomly assigned to placebo (N = 25) or montelukast (N = 25). Before and after training, we assessed BHR and EIB and markers of airway inflammation-that is, exhaled nitric oxide (eNO), pH, and cysteinyl-leukotriene concentration-in EBC. RESULTS: Training increased maximal workload and peak minute ventilation. After training, the methacholine dose causing a 20% fall in FEV1 (PD20) increased in both groups. A decreased slope of FEV1 decline at increasing methacholine dose was found only in montelukast-treated children. EIB prevalence halved after training in both groups (EIB + children, placebo group: 10 pretraining, 4 posttraining; EIB + children, montelukast group: 8 pretraining, 5 posttraining; P < 0.05 by chi on all children). Resting eNO was unaffected, whereas the pH of EBC decreased after training in both groups. Cysteinyl-leukotriene concentrations were low in most children at both times. During training, montelukast-treated children showed fewer asthma exacerbations compared with the same period of the previous year. CONCLUSIONS: In children with mild stable asthma, exercise training decreased bronchial responsiveness to methacholine. Montelukast also decreased bronchial reactivity (FEV1 slope) and protected against exacerbations, suggesting a beneficial synergistic action of these two interventions in mild asthma.

Deep inspiration-induced changes in lung volume decrease with severity of asthma.

We have previously reported that the magnitude of deep inspiration (DI)-induced bronchodilation is only slightly reduced in mild asthmatics, compared to healthy subjects. The aim of this study was to evaluate whether increased severity of asthma is associated with impairment in the ability of DI to induce changes in lung volume. Thirty-six consecutive asthmatics recruited from the Pulmonary and the Allergy Outpatient Clinics of the Institute of Respiratory Diseases of the University of Palermo were divided into 3 groups: Intermittent (I), Mild Persistent (MP) and Moderate-Severe (MS), based on GINA guidelines. Single dose methacholine (Mch) bronchoprovocations were performed in the absence of DI, to induce at least 15% reduction in inspiratory vital capacity (IVC) from baseline. The post-Mch IVC was followed by 4 consecutive DI and by another IVC, to determine the bronchodilatory effect of DI. The bronchodilatory effect of DI was found to significantly decrease with increasing severity of asthma (I: 68+/-5.4%, MP: 45+/-7.2%, MS: 4+/-15.6%; ANOVA: P<0.0001). Bronchodilation by DI, but not FEV(1) or FEV(1)/FVC, was also inversely correlated to symptom scores (r=-0.42, P=0.01) and to weekly salbutamol usage (r=-0.47, P=0.004). These observations provide support to the hypothesis that the attenuation of the bronchodilatory effect of DI contributes to the severity of the clinical manifestations of asthma.