Asthma in Competitive Cross-Country Skiers: A Systematic Review and Meta-analysis

Abstract

Introduction In cross-country skiing, the repetitive ventilation of large amounts of cold and dry air strains the airways. The aim of this systematic review was to establish an overview of the current literature on asthma in cross-country skiers, biathletes and ski-orienteers. Methods Six databases were searched on August 29, 2019. The search yielded 2161 articles. Thirty articles fulfilled the search criteria and were pooled together for a qualitative synthesis. Eight articles were included in the meta-analysis on the prevalence of asthma and the use of asthma medication. Results According to the meta-analysis, the prevalence of self-reported physician-diagnosed asthma in skiers was 21% (95% CI 14–28%). The onset age of asthma was higher in skiers than in non-skiers with asthma. The prevalence of asthma medication use was on average 23% (CI 95% 19–26%). Several studies reported that asthma was underdiagnosed in skiers, as previously healthy skiers without a prior asthma diagnosis or medication use were frequently found to fulfill diagnostic criteria for asthma according to lung function tests. Studies using bronchial biopsy demonstrated that eosinophilic asthma is not detected in skiers with asthma as often as it is in non-skiers with asthma and that there are signs of airway inflammation even in non-asthmatic skiers. Conclusion Our findings suggest that the accuracy and coverage of diagnosing asthma in skiers has improved over the recent decades. However, the optimal treatment and natural course of asthma in this population remain unclear. Future research should investigate how the intensity of training, airway infections and their treatment affect the development of asthma among skiers. PRD registration number CRD42017070940.

Effort-induced bronchospasm in athletes: modern views on pathogenesis and diagnosis in high-school teenagers

“…Thus, certain signs peculiar to the bronchial mucous membrane inflammatory process in athletes engaged in winter sports were revealed. Similar conclusions were reached by the authors of the research studying the level of macrophages and white blood cells in the material obtained in bronchoalveolar lavage (BAL), which resulted in a significant increase in the number of these cells in healthy athletes after intensive training under low-temperature conditions [31]. During the prospective clinical study, an advanced local inflammatory process in intensively training swimmers was revealed on the background of initially moderately infiltrated bronchial mucous membrane with eosinophils and lymphocytes [32].…”

Higher prevalence but later age at onset of asthma in cross‐country skiers compared with general population

“…asthma, asthma control, cross-country skiing, onset age of asthma, respiratory health cross-country skiers is reported to be found more often as neutrophilic than eosinophilic compared with asthma in the general population, 2 suggesting a difference in the underlying causes of asthma in these populations.…”

“…The prevalence of the use of asthma medication in cross-country skiers has varied between 18% and 36% and was approximately 21% in our recent meta-analysis. 2 However, there is lack of knowledge on how the use of asthma medication compares between skiers and nonskiers and whether the typical use of bronchodilators in skiers is on demand for symptoms or pre-emptively before exercise.…”

A heat and moisture-exchanging mask impairs self-paced maximal running performance in a sub-zero environment

“…Strategies to decrease the incidence of cold-induced airway obstructions could play a key role in improving the lung function of athletes, but it is important that any preventive strategy does not interfere with the potential to achieve optimal performance. The prevalence of asthma in cross-country skiers has been estimated at 23%, but may vary depending on the diagnostic criteria used (Mäki-Heikkilä et al 2020). In Sweden, the prevalence of self-reported, physician-diagnosed asthma has been recently reported at 9% (Borna et al 2019).…”

“…The prevalence of asthma in cross-country skiers has been estimated at 23%, but may vary depending on the diagnostic criteria used (Mäki-Heikkilä et al 2020 ). In Sweden, the prevalence of self-reported, physician-diagnosed asthma has been recently reported at 9% (Borna et al 2019 ).…”