Good aerobic fitness could prevent asthma exacerbation in adolescents during the cold seasons

Background: Adolescents with asthma can experience higher asthma exacerbation (AE) during the cold seasons. Also, improvement in exercise capacity reduces airway inflammation and corticosteroids consumption and improves asthma symptoms. Aim: To evaluate if aerobic fitness is associated with AE during the cold seasons. Method: Observational cohort study that included adolescents with asthma aging between 12 and 18 years. Subjects had asthma diagnosis in accordance with the Global Initiative for Asthma guideline and were under optimized pharmacological treatment for, at least, six months. Exercise capacity was evaluated by a cardiopulmonary exercise testing using an incremental ramp protocol (20W/min) and subjects with VO2peak >83% were considered with good aerobic fitness according to the European Respiratory Society guideline. After that, subjects were followed during 12 months and daily life physical activity (DLPA) and AE were evaluated monthly. DLPA was evaluated by a triaxial accelerometer in 6 consecutive days. AE was defined as worsening of asthma requiring an increase in inhaled corticosteroids consumption. Results: Forty-one adolescents were evaluated and 22 (54%) had good aerobic fitness. No difference in the AE was observed between subjects with good or low aerobic fitness (respectively, 18.2% vs 31.6%, p=0.31). Also, subjects that experienced AE 10 (24%) presented a similar number of steps per day and aerobic fitness than those that did not present AE (respectively, 7,827±3,803 vs 8,905±4,546 steps and 86±16% vs 87±16% VO2peak, p>0.05). Conclusion: Good aerobic fitness is not associated with a reduction in exacerbation during the cold seasons in adolescents with asthma.