Gender differences in the prevalence of airway hyperresponsiveness and asthma in athletes.

BACKGROUND: Although athletes have a high prevalence of airway hyperresponsiveness (AHR) and asthma, little is known about possible gender differences in regard to these features. We looked at the comparative prevalence of AHR, physician-diagnosed asthma and respiratory symptoms during exercise in female (F) and male (M) athletes. METHOD: A retrospective analysis was done on 2 groups of athletes: Group 1 (n=100) taking part in a study on the prevalence of AHR to methacholine (PC(20)<16mg/ml) and Group 2 (n=698), taking part in a provincial survey on the prevalence of physician-diagnosed asthma. Subjects from both groups filled the same questionnaire on respiratory symptoms during exercise (breathlessness, wheezing and chest tightness). RESULTS: In Group 1, prevalence of AHR was significantly higher in female (60%) compared with male (21.5%, p<0.0001) athletes despite a similar prevalence of physician-diagnosed asthma (F: 17.1%, M: 15.4%, p>0.05). Respiratory symptoms during exercise were more frequently reported in females (37.1%, M: 16.9%, p=0.02); however, when corrected for the PC(20), this difference became non-significant. In Group 2, the prevalence of physician-diagnosed asthma was not different between genders (F: 12.5%, M: 14%, p>0.05) but respiratory symptoms during exercise were more often reported in female (19.4%) than in male (12.2%, p=0.01) athletes. CONCLUSIONS: This analysis shows a higher prevalence of AHR and exercise-induced respiratory symptoms in female compared to male athletes, but a similar prevalence of physician-diagnosed asthma. This suggested that the increase in respiratory symptoms in female athletes failed to translate into a higher prevalence of physician-diagnosed asthma.

Lower airway inflammatory responses to high-intensity training in athletes.

PURPOSE: There is an increased prevalence of asthma and airway hyperresponsiveness in elite athletes, particularly in swimmers. High intensity exercise may induce airway inflammation and subsequent remodelling in these subjects. Our aim was to evaluate the effects of high-intensity training on induced-sputum cell populations in elite athletes. METHODS: Swimmers and runners with hyperresponsive airways (SH and RH), defined by a provocative concentration of methacholine inducing a 20% decrease in FEV1 (PC20) <16 mg/ml or with normoresponsive airways (PC20 > 16 mg/ml; SN, RN) to methacholine were enrolled. The mean PC20 was 2.27 mg/ml in SH (n=12), 32.2 in SN (n=10), 3.25 in RH (n=10) and 41.5 in RN (n=13). All athletes had two induced sputum analyses at one- to two-week intervals in random order: after a period of 72 hours without training, 24 hours after a training session. RESULTS: PC20 was unchanged after training. The median % neutrophils and eosinophils in groups SH, SN, RH, and RN, respectively, were 26.5-1.6, 8.6-0.3, 28.0-0.03 and 25.5-0.1 before and 45.0-0.5, 31.1-0.4, 54.0-0.6 and 48.3-0.3 after training. While the magnitude of the increase in neutrophils was similar for all groups, it reached statistical significance (pre-post-training) only in the SH group (P = 0.039). CONCLUSION: A one-hour session of high-intensity training was associated with an increase in airway neutrophils among hyperresponsive swimmer athletes, while airway responsiveness remained unchanged in all groups.

Comparative prevalence of asthma in different groups of athletes: a survey.

BACKGROUND: The type of air predominantly inhaled during training seems to play an important role in the development of airway hyperresponsiveness in athletes; however, this factor has not been evaluated for asthma. OBJECTIVE AND PATIENTS: To compare the prevalence of self-reported and/or physician-diagnosed asthma among four groups of athletes categorized according to the type of air predominantly inhaled during training: cold air (n=176), dry air (n=384), humid air (n=95), and mixed dry and humid air (n=43). METHOD: Self-administrated questionnaires were used. RESULTS: One hundred seven (15.3%) of the 698 athletes reported having asthma; of these 107 athletes, 92 had physician-diagnosed asthma. No significant differences were found for the prevalence of asthma: 15.9% (cold air), 15.4% (dry air), 12.6% (humid air) and 18.6% (mixed dry and humid air), respectively (P>0.05). Furthermore, no significant differences were observed among the groups for the prevalence of confirmed atopy, cold/flu or respiratory infections (all P>0.05), except for the prevalence of hay fever, which was significantly lower among athletes of the dry air group (P=0.04). Athletes having a first-degree relative with asthma did not have a higher prevalence of asthma than those who did not (P>0.05). CONCLUSION: The prevalence of asthma was not significantly different among the four groups of athletes and it was not associated with a family history of asthma.

Prevalence of respiratory symptoms in an athlete population.

This study aimed to look at the prevalence and type of respiratory symptoms experienced by athletes and to assess the possible influence on the perception of symptoms of training duration and environment. A group of 698 athletes (107 with diagnosed or self-reported asthma) filled out a questionnaire on their respiratory condition. They exercised either in cold air (n = 176), dry air (n = 384), humid air (n = 95) or mixed dry and humid air (n = 43). Past exercise-related symptoms reported by athletes were breathlessness (48.7%), phlegm production (22.8%), wheezing (15.6%), cough (15.2%), and chest tightness (7.4%). Only 25% of asthmatic athletes reported having current exercise-induced symptoms of breathlessness, 21.7%, wheezing and 17.4%, chest tightness; current exercise-induced symptoms of breathlessness, wheezing or chest tightness were also reported, respectively, in 38.9%, 3.6% and 2.7% of athletes without a diagnosis of asthma. The perception of exercise-induced symptoms was not influenced by the duration of training or environment. In conclusion, (1) a minority of asthmatic athletes report troublesome respiratory symptoms with exercise, (2) breathlessness is not more frequently reported in asthmatic athletes than in those without such diagnosis while cough and wheezing are more common in asthmatic subjects and (3) the prevalence of respiratory symptoms is independent of training environment and duration of training.

Are questionnaires on respiratory symptoms reliable predictors of airway hyperresponsiveness in athletes and sedentary subjects?

This study aimed at determining the frequency of respiratory symptoms in high-level athletes and whether respiratory questionnaires are reliable predictors of airway hyperresponsiveness (AHR) in this population compared with control subjects. One hundred high-level athletes exercising in different conditions of ambient air (dry, humid, cold or mixed dry and humid) and 50 sedentary control subjects answered four question sets on exercise-induced symptoms of postnasal drip (Q1), breathlessness, chest tightness and wheezing (Q2), and cough (Q3). Another question set (Q4) evaluated the self-description of nociceptive sensations associated with respiratory symptoms. Methacholine inhalation tests were performed in all subjects to obtain a 20% fall in forced expiratory volume in 1 second (PC20). AHR could be detected by questionnaires in 37 of 44 (84%) subjects with a PC20 < 8 mg/mL. Sensitivity to detect AHR varied between the different subgroups of athletes with each of the question sets; however, no significant differences in sensitivity were observed between the groups of athletes and controls except for Q3 (P=.007), in which athletes exercising in cold air reported more exercise-induced cough. Q2 had a better specificity (83%) than Q3 (77%) and Q4 (64%). Combined question sets revealed that three swimmers, two triathletes, and two controls, who answered negatively to all question sets, had a PC20 < 8 mg/mL. Questionnaires on symptoms and on associated nociceptive sensations may help to detect AHR as well in athletes and controls, although for some subgroups of athletes such as swimmers and triathletes and in some controls, false negative questionnaires can be observed and AHR underreported.