Physical exercise, systemic inflammation and adult-onset asthma: a 12-year follow-up study

Objective: Physical exercise in treatment of asthma is scarcely studied with no clear exercise guidelines for asthmatics. We aimed to investigate the associations between physical exercise frequency, systemic inflammation and asthma control. This has not been previously studied in adult-onset asthma.

Methods: This study is part of Seinäjoki Adult Asthma Study (SAAS), where 203 patients with adult-onset asthma were evaluated in 2012-2013. Exercise frequency was recorded with a structured lifestyle questionnaire. Study population was divided into two categories by exercise frequency: Low-frequency group exercised ≤2 times/week and high frequency group >2 times/week. Blood inflammatory markers were measured and IL-6 > 1.55 pg/ml and hs-CRP > 4.12 mg/l indicated systemic inflammation.

Results: High-exercise frequency group had lower levels of hs-CRP (p = 0.007), IL-6 (p = 0.015), suPAR (p = 0.008) and adipsin (p = 0.031) and higher levels of adiponectin (p = 0.010) than low-exercise frequency group. In logistic multivariate regression models, higher-exercise frequency lowered odds for elevated hs-CRP (OR = 0.37, 95% CI 0.15-0.94) and IL-6 levels (OR = 0.43, 95% CI 0.20-0.91), after adjusting for possible confounding factors. There was no difference in lung function tests, asthma control test or airways questionnaire 20 scores between the exercise frequency groups. However, differences were found in single symptom questions; high-exercise frequency group had less symptoms during light housework and laughing but experienced more limitation of activity in self-reports.

Conclusions: Higher-exercise frequency is associated with lower level of systemic inflammation in patients with adult-onset asthma but no clear association was found to asthma outcomes. Exercise frequency may be associated with lesser amount of some individual asthma symptoms.