Asthma and wheezing among Norwegian elite athletes.
ABSTRACT The objectives were to estimate the prevalence of self-reports of asthma and wheezing among Norwegian elite athletes compared with the general population and to estimate the associations between asthma and types of sports, exercise and team level.
The study population included all Norwegian elite athletes on the national junior and senior teams in 1997 (N = 1620) and a random sample from the general population (N = 1680). The surveys included items for asthma, respiratory symptoms, the history of participation in sports, sports events, and exercise and team level. The associations between the exposure variables and the outcomes adjusting for potential confounding factors were estimated using logistic regression. Crude (c) and adjusted odds ratio (aOR) with 95% confidence interval (CI) are presented.
The prevalence of asthma was greater among athletes (10.0%) compared with that in the general population (6.9%) and remained so after controlling for confounders, aOR = 1.5 (95%CI 1.1-2.1). The risk of asthma was highest in sports requiring strength and endurance. This was the case for comparisons between athletes and the general population, aOR = 3.5 (1.6-7.6) for strength and aOR = 2.2 (1.4-3.5) for endurance sports. Comparisons within the sample of athletes using technical sports as the reference category revealed similar results, aOR = 3.0 (1.1-8.0) and aOR = 2.0 (1.0-4.3), respectively. Furthermore, asthma was more common among female than male athletes (aOR 1.7 (1.1-2.7)). Training more than 20 h x wk(-1) was associated with asthma when compared with levels of training less than 10 h x wk(-1) (aOR 1.9 (1.0-4.1)).
These results indicate that asthma is more common among athletes compared with the general population. Asthma among athletes may define a subgroup of asthma cases for whom etiology is related to extensive exercise.
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ABSTRACT: Asthma is often reported by elite athletes, especially endurance athletes. The aim of this article is to review current knowledge of mechanisms and management of exercise-induced asthma (EIA) in adult elite athletes. The mechanisms underlying EIA is incompletely understood, but the two prevailing hypotheses are the hyper-osmolarity and the thermal hypothesis. Both hypotheses consider inflammation and activation of mast cells as being crucial for the development of EIA, although the assumed mechanisms triggering the inflammatory response differ. Objective testing is of utmost importance in the diagnosis of EIA in elite athletes. Management of EIA can be divided into pharmacologic and non-pharmacologic treatment. The basic principles for the treatment of EIA in elite athletes should be as for any asthmatic individual, including use of inhaled corticosteroids (ICS), β(2)-agonists, and leukotriene antagonists. However, evidence suggests that daily use of β(2)-agonists might lead to the development of tolerance. ICS therapy is, due to its anti-inflammatory effects, the recommended primary therapy for EIA also in elite athletes. All doctors treating individuals with asthma, especially elite athletes, should remain updated on doping aspects of asthma therapy. Non-pharmacologic management of EIA in elite athletes includes physical warm-up, which takes advantage of the refractory period following an attack of EIA, whereas high intake of antioxidants may reduce airway inflammation. Wearing heat masks, specially designed for outdoor winter athletes, might protect against bronchoconstriction triggered by inhalation of cold and dry air. EIA in elite athletes should be managed as in any individual with asthma, but the risk of developing tolerance to bronchodilators as well as doping aspects should always be taken into account.Journal of Asthma 04/2012; 49(5):480-6. · 1.85 Impact Factor
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ABSTRACT: Asthma prevalence in athletes is variable, depending on the sport and training conditions. To investigate the prevalence of obstructive airflow limitation, asthma control and lung volume differences in a control group and five groups of collegiate athletes--outdoor field, indoor court, endurance, combat sports and swimming. Three hundred and five athletes completed a respiratory questionnaire and performed spirometry during normal training conditions, to determine FEV1, FVC and PEFR pre- and at 5, 10 and 15 minutes post-exercise. Between and within group analysis was carried out using single factor and repeated measures ANOVA. Previous diagnosis of asthma was reported by 24%, outdoor field sports 4.9%, indoor court sports 2.3%, endurance events 2.6%, combat sports 3%, swimming 6.9% and controls 4.3%. Mean FEV1 and FVC data, expressed as percentage of predicted, were greatest in swimming and lowest in controls. Swimming showed a significant rise in FEV1 post-exercise, indoor court and endurance sports demonstrated no change and outdoor field, combat and control groups showed a fall in FEV1 post-exercise. Warm humid training conditions appear protective against exercise-induced asthma. The greatest reductions in lung volumes occurred following high intensity exercise under cool conditions in the poorly aerobically conditioned.Irish Journal of Medical Science 04/2012; 171(4):202-5. · 0.51 Impact Factor
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ABSTRACT: β(2) -adrenergic receptor (β(2) -AR) agonists have been used as ergogenics by athletes involved in training for strength and power in order to increase the muscle mass. Even though anabolic effects of β(2) -AR activation are highly recognized, less is known about the impact of β(2) -AR in endurance capacity. We presently used mice lacking β(2) -AR [β(2) -knockout (β(2) KO)] to investigate the role of β(2) -AR on exercise capacity and skeletal muscle metabolism and phenotype. β(2) KO mice and their wild-type controls (WT) were studied. Exercise tolerance, skeletal muscle fiber typing, capillary-to-fiber ratio, citrate synthase activity and glycogen content were evaluated. When compared with WT, β(2) KO mice displayed increased exercise capacity (61%) associated with higher percentage of oxidative fibers (21% and 129% of increase in soleus and plantaris muscles, respectively) and capillarity (31% and 20% of increase in soleus and plantaris muscles, respectively). In addition, β(2) KO mice presented increased skeletal muscle citrate synthase activity (10%) and succinate dehydrogenase staining. Likewise, glycogen content (53%) and periodic acid-Schiff staining (glycogen staining) were also increased in β(2) KO skeletal muscle. Altogether, these data provide evidence that disruption of β(2) -AR improves oxidative metabolism in skeletal muscle of β(2) KO mice and this is associated with increased exercise capacity.Scandinavian Journal of Medicine and Science in Sports 08/2012; · 3.21 Impact Factor