Comparative and synergistic effects of fish oil supplementation and a leukotriene receptor antagonist on exercise-induced bronchoconstriction and airway inflammation in subjects with asthma

Introduction. The relationship of fish oil supplementation with available pharmacotherapy for treating exercise-induced bronchoconstriction (EIB) has yet to be examined. The primary aim of this study was to determine the comparative and synergistic effects of fish oil supplementation and montelukast (SingulairRTM) on airway inflammation and the severity of EIB. The secondary and tertiary aims of this study were to examine a variety of methods for assessing airway inflammation and its relationship to the severity of EIB.;Methods. Twenty asthmatic subjects with EIB were assigned to receive 1 of 2 treatment regimens for a period of 3 weeks. The regimens consisted of (1) active montelukast and fish oil placebo each day (n=10) or (2) placebo montelukast and active fish oil (n=10). Following the 3 week period both groups (n=20) received active montelukast and active fish oil for a further 3 weeks. Subjects underwent a eucapnic voluntary hyperventilation (EVH) challenge at the beginning of the study and at the end of each supplementation period. Pulmonary function, exhaled nitric oxide (FENO), exhaled breath condensate (EBC), and urine were collected pre- and post-EVH challenge.;Results. All three treatments significantly reduced (p<0.05) the post-exercise fall in pulmonary function and attenuated airway inflammation as demonstrated by a significant reduction (p<0.05) in pre- and post-EVH inflammatory mediator production, and as shown by a significant increase (p<0.05) in airway pH. Inflammatory mediators in EBC and urine were shown to significantly increase (p<0.05) from pre- to post-EVH challenge. In addition, FENO and EBC pH were found to be significantly correlated (p<0.05) to the severity of EIB.;Conclusion. Fish oil is as effective as montelukast in suppressing EIB and airway inflammation in asthmatic individuals. However, the combination of the two treatments was not more effective than either treatment alone. In addition, this study has also shown that EBC is a non-invasive technique that can be used to detect changes in inflammatory mediator production in response to an EVH challenge, and that EBC pH and FENO may be useful biomarkers for assessing airway inflammation and predicting the severity of the EIB response.