Effect of Pharmacological Treatment on Exercise-Induced Bronchoconstriction and Allergic Inflammatory Response in Endurance Athletes

Abstract

Background: Endurance athletes (EA) with lung disease and allergic inflammation have worse performance.

Purpose: To examine whether pharmacological treatment can reduce airway disorders such as exercise-induced bronchoconstriction (EIB) and allergic inflammatory response (AIR) in EA.

Study design: Prospective, controlled clinical trial.

Methods: EA who were marathon runners underwent eucapnic voluntary hyperventilation (EVH) for screening assessment. EA who fulfilled the criteria for an EIB+ after an EVH were included in the treatment group (EIB+; n=13), and those who did not were included in the control group (CON; n=18). The athletes were assessed before and 30 days after the intervention. Outcomes included cardiopulmonary exercise testing, lung function, allergic symptoms (allergic questionnaire for athletes [AQUA©]), AIR (T helper [Th]-1, Th2, and Th17 lymphocytes in cell cultures), inflammatory mediator expression, salivary immunoglobulin (Ig)A, blood cortisol, blood IgE levels, and airway inflammation (fraction exhaled nitric oxide [FeNO]). Both groups were advised to keep the same training routine, and only the EIB+ received pharmacological treatment with inhaled corticosteroids (400-800 mcg/day) and long-acting bronchodilators (12 mcg/day). The CON and EIB+ groups underwent the same assessments after the intervention and were compared pre- and post-intervention, and effect sizes were calculated.

Results: EIB+ (males, age 28.1±7.4 years, BMI 20.3±1.0 kg/m2) CON (males, age 29.8±6.5 years, BMI 20.5±1.6 kg/m2) participated. At baseline, the O2 peak, lung function, allergic symptoms, IgE, IgA, FeNO levels, and AIR were not significancly different between groups (p>0.05). After pharmacological treatment, only the EIB+ group showed a decrease in EIB (p<0.001) and an increase in VO2peak compared to baseline (p<0.05). However, no difference was observed in the expression of inflammatory mediators (p>0.05).

Conclusion: Pharmacological treatment reduces EIB and increases the aerobic perforance/fitness in endurance athletes. These benefits occur without modification of the AIR.

Level of evidence: Level II- Prospective Comparative Study.

Keywords: allergy; lung; marathon; running; triathlon.

Figure 1.. Changes induced by intervention.

Data are presented as average and standard deviation (SD). CON = control group; EIB+ = exercise-induced bronchoconstriction plus pharmacological treatment; Forced Expiratory FEV1 = Volume Exhaled in the first second; % = percentage; EVH = Eucapnic voluntary hyperpnea. Figure 1A shows the change in FEV1 in % after the EVH in the Treatment (EIB+, square in white, n = 13) and Control group (CON, triangle in black, n = 18) at the baseline. Figure 1B shows the change in FEV1 (%) in the EIB+ before (black square) and after (white square) pharmacological treatment. *p<0.05 when compared EIB+ with CON. #p<0.05 when compared EIB+ at baseline and after pharmacological treatment.

Figure 2.. Changes in the airways after intervention.

CON = control group; EIB+ = exercise-induced bronchoconstriction plus pharmacological treatment; % = percentage; FEV1 = volume in the first second. Data are presented as % of athletes presenting EIB (drop ≥10% in FEV1) before (black) and after (grey) 30 days of pharmacological treatment in the EIB+ (n = 13).