Sex Differences in Exercise-Induced Bronchoconstriction in Athletes: A Systematic Review and Meta-Analysis

The therapeutic role of inspiratory muscle training in the management of asthma: a narrative review

Asthma is a disorder of the airways characterized by chronic airway inflammation, hyperresponsiveness, and variable recurring airway obstruction. Treatment options for asthma include pharmacological strategies, whereas nonpharmacological strategies are limited. Established pharmacological approaches to treating asthma may cause unwanted side effects and do not always afford adequate protection against asthma, possibly because of an individual's variable response to medications. A potential nonpharmacological intervention that is most available and cost effective is inspiratory muscle training (IMT), which is a technique targeted at increasing the strength and endurance of the diaphragm and accessory muscles of inspiration. Studies examining the impact of IMT on asthma have reported increases in inspiratory muscle strength and a reduction in the perception of dyspnea and medication use. However, because of the limited number of studies and discordant methods between studies more evidence is required to elucidate in individuals with asthma the efficacy of IMT on inspiratory muscle endurance, exercise capacity, asthma control, symptoms, and quality of life as well as in adolescents with differing severities of asthma. Large randomized controlled trials would be a significant step forward in clarifying the effectiveness of IMT in individuals with asthma. Although IMT may have favorable effects on inspiratory muscle strength, dyspnea, and medication use, the current evidence that IMT is an effective treatment for asthma is inconclusive.

Rates of Reporting and Analyzing Patient Sex in Sports Medicine Research: A Systematic Review

BACKGROUND

Sex differences in sports medicine are well documented. However, no studies to date have reviewed the rate at which sex is reported and analyzed in the athlete-specific orthopaedic sports medicine literature.

PURPOSE

To determine the rates of reporting and analyzing patient sex in athlete-specific sports medicine literature.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

Articles published by the 3 journals of the AOSSM (American Journal of Sports Medicine [AJSM], Orthopaedic Journal of Sports Medicine, and Sports Health: A Multidisciplinary Approach) between 2017 and 2021 were considered for inclusion. Original sports medicine research studies that isolated athletes were included. Studies that isolated sports that are predominantly single sex at the college and/or professional levels (football, baseball, softball, and wrestling) were excluded.

RESULTS

Of the 5140 publications screened, 559 met the inclusion criteria. In total, 93.9% of all studies reported patient sex, and 34.7% of all studies analyzed patient sex. However, 143 studies only included males and 50 studies only included females (n = 193). When excluding these single-sex studies, analysis of the remaining 366 studies found that the rate of sex-specific analysis increased to 53.0%. Rates of reporting patient sex did not significantly differ by journal or by year. Similarly, rates of analyzing patient sex did not differ by year, but Sports Health analyzed sex the most frequently, and AJSM analyzed sex the least frequently (P = .002). Studies that isolated college (84.1%), youth (66.7%), or recreational (52.6%) athletes analyzed sex at or above the overall rate of 53.0%, but studies of elite athletes (35.7%) tended to analyze sex less frequently.

CONCLUSION

Patient sex is well reported in the athlete-specific sports medicine literature (93.9% of included studies reported sex), demonstrating that most studies include sex as a demographic variable. However, patient sex was analyzed only in 53.0% of studies that included both male and female patients. Given that athlete-specific sex differences are known to exist within the field of sports medicine, many studies that could benefit from using patient sex as a variable for analysis likely fail to do so.

A longitudinal study of exercise-induced bronchoconstriction and laryngeal obstruction in high school athletes

BACKGROUND

Exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO) are common in elite athletes. Knowledge of which factors are related to incident EIB and EILO is limited. The aim of this study was to explore the course of EIB and EILO in adolescent athletes over a 2 years period and baseline characteristics related to incident EIB.

METHODS

Questionnaire data on respiratory symptoms, asthma, and aeroallergy and results of objective EIB and EILO tests were collected from 58 participants (27 tested for EILO) at baseline and after 2 years (follow-up). Associations between incident EIB and baseline asthma-like symptoms, exercise-induced symptoms, fractional exhaled nitric oxide (FeNO), aeroallergy, and sex were assessed using logistic regression models.

RESULTS

Ten participants had incident EIB, and eight participants had persistent EIB. Five were EIB positive at baseline but negative at follow-up, while 35 participants were EIB negative at both time points. Having incident EIB was associated with reporting waking up with chest tightness (OR = 4.38; 95% CI: 1.06, 22.09). Reporting an increased number of asthma-like symptoms increased the likelihood of incident EIB (OR = 2.78; 95% CI: 1.16, 6.58). No associations were found between exercise-induced symptoms, FeNO, aeroallergy, or sex and incident EIB. Incident EILO was found in three and persistent EILO in two of the 27 participants tested.

CONCLUSION

Two in nine had incident EIB and one eighth had incident EILO, suggesting that recurrent testing for EIB and EILO may be relevant in young athletes. Particularly, EIB-negative athletes reporting multiple asthma-like symptoms could benefit from recurrent EIB testing.

Demographics, Treatment Patterns, and Morbidity in Patients with Exercise-Induced Bronchoconstriction: An Administrative Claims Data Analysis

PURPOSE

Exercise-induced bronchoconstriction (EIB) is generally treated with short-acting β2-agonists (SABA) before exercising, to prevent symptoms. Real-world data on treatments and outcomes for patients with EIB alone (EIBalone), or with asthma (EIBasthma), in the USA are limited. This study compared demographics, treatment patterns, morbidity, and costs of treating EIB between these two groups of patients.

PATIENTS AND METHODS

Administrative claims from US IBM® MarketScan® Research databases were analyzed retrospectively. Patients aged ≥4 years filling a SABA claim between 1/1/2011 and 12/31/2016 were evaluated. Patients were indexed on a random SABA claim and required to have 12 months' continuous eligibility pre- and post-index, ≥1 maintenance medication and/or SABA fill post-index, and were designated EIBalone or EIBasthma according to diagnostic codes (EIB only or EIB plus asthma, respectively). Descriptive statistics were used.

RESULTS

In total, 13,480 patients had EIBalone and 14,862 had EIBasthma. Compared with EIBasthma, the EIBalone group was older (mean[SD] 20.4[13.6] vs 17.8[13.6] years), had more females (60.7% vs 54.7%), and filled fewer SABA claims (1.9[1.4] vs 2.5[2.2]) (all p<0.001). A smaller proportion of patients in the EIBalone than EIBasthma group had maintenance therapy claims (79.9% vs 90.6%, p<0.001). The EIBalone group also had a lower proportion of patients with oral or injectable corticosteroid claims (29.4% vs 32.0%) and asthma and/or EIB-related emergency department (1.0% vs 13.0%) or outpatient visits (65.1% vs 72.3%; all p<0.0001). Annual days' supply of oral corticosteroids was similar between groups (mean[SD] EIBalone: 20.7[30.8] vs EIBasthma: 19.8[28] days).

CONCLUSION

Individuals with EIBalone or EIBasthma demonstrate considerable morbidity. New treatment paradigms may be needed to optimize outcomes for both patient groups.

The Specificities of Elite Female Athletes: A Multidisciplinary Approach

Female athletes have garnered considerable attention in the last few years as more and more women participate in sports events. However, despite the well-known repercussions of female sex hormones, few studies have investigated the specificities of elite female athletes. In this review, we present the current but still limited data on how normal menstrual phases, altered menstrual phases, and hormonal contraception affect both physical and cognitive performances in these elite athletes. To examine the implicated mechanisms, as well as the potential performances and health risks in this population, we then take a broader multidisciplinary approach and report on the causal/reciprocal relationships between hormonal status and mental and physical health in young (18-40 years) healthy females, both trained and untrained. We thus cover the research on both physiological and psychological variables, as well as on the Athlete Biological Passport used for anti-doping purposes. We consider the fairly frequent discrepancies and summarize the current knowledge in this new field of interest. Last, we conclude with some practical guidelines for eliciting improvements in physical and cognitive performance while minimizing the health risks for female athletes.

Sex and Gender Differences in Lung Disease

Sex differences in the anatomy and physiology of the respiratory system have been widely reported. These intrinsic sex differences have also been shown to modulate the pathophysiology, incidence, morbidity, and mortality of several lung diseases across the life span. In this chapter, we describe the epidemiology of sex differences in respiratory diseases including neonatal lung disease (respiratory distress syndrome, bronchopulmonary dysplasia) and pediatric and adult disease (including asthma, cystic fibrosis, idiopathic pulmonary fibrosis, chronic obstructive pulmonary disease, lung cancer, lymphangioleiomyomatosis, obstructive sleep apnea, pulmonary arterial hypertension, and respiratory viral infections such as respiratory syncytial virus, influenza, and SARS-CoV-2). We also discuss the current state of research on the mechanisms underlying the observed sex differences in lung disease susceptibility and severity and the importance of considering both sex and gender variables in research studies' design and analysis.

Asthma, atopy, and exercise: Sex differences in exercise-induced bronchoconstriction

Asthma is a chronic inflammatory lung disease affecting approximately 7.7% of the US population. Sex differences in the prevalence, incidence, and severity of asthma have been widely described throughout the lifespan, showing higher rates in boys than girls before puberty, but a reversed pattern in adults. Asthma is often associated with atopy, i.e. the tendency to develop allergic diseases, and can be worsened by environmental stimuli and/or exercise. While not exclusive to patients with asthma, exercise-induced bronchoconstriction (EIB) is a common complication of athletes and individuals who exercise regularly. Currently, there is limited research on sex differences in EIB and its relationship with atopy and asthma in men and women. In this minireview, we summarize the available literature on this topic. Overall, the collective knowledge supports the notion that physiological changes triggered during exercise affect males and females differently, suggesting an interaction among sex, exercise, sex hormones, and atopic status in the course of EIB pathophysiology. Understanding these differences is important to provide personalized management plans to men and women who exercise regularly and suffer from underlying asthma and/or atopy.

Validity and repeatability of the Pediatric Allergy Questionnaire for Athletes (AQUAped) for the screening of atopy

BACKGROUND

High atopy prevalence has been reported in athletes. Having an age-specific questionnaire for predicting atopy is important for an optimal management of young athletes. The study objectives were as follows: (i) developing a scoring system for the Pediatric Allergy Questionnaire for Athletes (AQUAped); (ii) identifying the optimal age target within the range 7-14 years; (iii) assessing AQUAped validity and repeatability in the identified target population.

METHODS

A total of 133 young athletes (age 7-14 years) were recruited. Following a screening visit, the participants filled AQUAped at baseline (T0) and after 7 days (T1), concomitantly undergoing skin prick testing. Using atopy as the gold standard (positivity to ≥1 aeroallergen), the 12 core items were scored based on their likelihood ratios, and a total score was calculated. The optimal cut-off was identified based on the Youden's criterion. The repeatability of AQUAped was assessed through the intra-cluster correlation coefficient (ICC). The optimal age target was identified as the largest age range associated with an acceptable cross-validated area under the receiver operating characteristic curve (AUC ≥ 0.70) and an excellent ICC (≥0.75).

RESULTS

Forty (30%) children were atopic; the optimal age target was 10-14 years (cross-validated AUC = 0.70, ICC = 0.81). AQUAped total score ranged from -26 to 75, and only 5% of non-atopic children had AQUAped ≥ 24. AQUAped ≥ 2 had 82% specificity, 60% sensitivity, and 74% overall accuracy.

CONCLUSION

Developing and testing a scoring system for AQUAped showed that it is a valid and reliable tool for the screening of atopy in young athletes aged 10-14 years.

Exercise-induced bronchoconstriction and bronchodilation: investigating the effects of age, sex, airflow limitation and FEV1

Exercise-induced bronchoconstriction (EIBc) is a recognised response to exercise in asthmatic subjects and athletes but is less well understood in an unselected broad population. Exercise-induced bronchodilation (EIBd) has received even less attention. The objective of this study was to investigate the effects of age, sex, forced expiratory volume in 1 s (FEV₁) and airflow limitation (FEV₁/forced vital capacity (FVC) <0.7) on the prevalence of EIBc and EIBd.This was a retrospective study based on incremental cardiopulmonary exercise testing on cycle ergometry to symptom limitation performed between 1988 and 2012. FEV₁ was measured before and 10 min after exercise. EIBc was defined as a percentage fall in FEV₁ post-exercise below the 5th percentile, while EIBd was defined as a percentage increase in FEV₁ above the 95th percentile.35 258 subjects aged 6-95 years were included in the study (mean age 53 years, 60% male) and 10.3% had airflow limitation (FEV₁/FVC <0.7). The lowest 5% of subjects demonstrated a ≥7.6% fall in FEV₁ post-exercise (EIBc), while the highest 5% demonstrated a >11% increase in FEV₁ post-exercise (EIBd). The probability of both EIBc and EIBd increased with age and was highest in females across all ages (OR 1.76, 95% CI 1.60-1.94; p<0.0001). The probability of EIBc increased as FEV₁ % pred declined (<40%: OR 4.38, 95% CI 3.04-6.31; p<0.0001), with a >2-fold increased likelihood in females (OR 2.31, 95% CI 1.71-3.11; p<0.0001), with a trend with airflow limitation (p=0.06). The probability of EIBd increased as FEV₁ % pred declined, in the presence of airflow limitation (OR 1.55, 95% CI 1.24-1.95; p=0.0001), but sex had no effect.EIBc and EIBd can be demonstrated at the population level, and are influenced by age, sex, FEV₁ % pred and airflow limitation.