Inhaled corticosteroid (ICS) is a potent anti-inflammatory agent that attenuates airway inflammation, improves asthma control, and lowers the risk of acute worsening. However, due to local and systemic side effects, and various other reasons, many patients wish to take as little medication as possible. Furthermore, some patients, especially those with obesity and type 2 low inflammation, tend to respond less to ICS treatment. As aerobic exercise improves asthma control, it could be a putative strategy to lower ICS dose without compromising asthma control. Although exercise is widely accepted as a supplementary treatment of asthma, its potential for reducing the need for ICS has yet to be evaluated.
In a recently published study in The Journal of Allergy and Clinical Immunology: In Practice, Pitzner-Fabricius et al. undertook a randomized controlled trial investigating the corticosteroid-sparing effect of 6 months of supervised high-intensity interval training (HIIT) 3-times a week using spinning-bikes. An additional 6 months of follow-up was included to evaluate the long-term effects of the exercise intervention.
A total of 150 untrained patients with symptomatic, persistent asthma, treated year-round with ICS, were included. Participants were randomly assigned to either an exercise group (n=102) or a control group (n=48), using asthma symptoms, level of blood eosinophilia and sex as stratification factors. A clinical assessment was performed by a blinded assessor at baseline and every second month. The patients in both groups had their asthma treatment adjusted (e.g., reduced, increased or no change) based on this assessment using a rigid, predefined algorithm. The main scope was to evaluate if exercise could reduce the dose of daily ICS, while the secondary outcomes focused on markers of disease control and physical activity.
Compared with the control group, the exercise group experienced a significant reduction in their daily use of ICS. After six months of HIIT, the reduction was 234ug, corresponding to a 24% reduction, and this was increased to 32% after the follow-up period. Importantly, this reduction was found without compromising markers of asthma control, including inflammatory markers, asthma symptoms, and exacerbations. The authors performed a subgroup analysis to identify patients with a large (two-step) reduction in asthma treatment based on baseline characteristics. This analysis showed that patients with uncontrolled asthma, based on either symptoms or an exacerbation requiring systemic steroid, and female patients with obesity were significantly more likely to be large responders when allocated to the exercise group. This knowledge could guide clinicians in identifying patients likely to benefit greatly from aerobic exercise. The authors conclude that their results add to the mounting data suggestive of exercise having a role in future asthma management beyond the general health benefits.
Dr. Sara Dever of Allergy & Asthma Care comments: "This study adds to the evidence that aerobic exercise can improve asthma control. Regular exercise is important for a wide range of health benefits, and it is becoming increasingly clear that improved asthma control is one of them."
