Effects of acute psychological stress induced in laboratory on physiological responses in asthma populations: A systematic review.

BACKGROUND: Psychological stress has long been suspected to have a deleterious effect on asthma, with acute psychological stress being associated with physiological responses in asthma patients.

OBJECTIVES: The purpose of this systematic review was to provide a narrative synthesis of the impact of acute laboratory psychological stress on physiological responses among asthma patients.

METHODS: An extensive search was conducted by two independent authors using Pubmed, PsycINFO, PsyArticles and the Cochrane Library electronic databases (up to September 2016). English and French articles which assessed physiological responses during or post-stress and compare them to baseline or pre-stress values were included.

RESULTS: Thirty-two studies met the inclusion criteria. Studies indicated that exposure to active stressors (e.g., arithmetic tasks) was associated with an increase in sympathetic nervous system (SNS) responses, cortisol, and inflammatory responses, but had little effect on the caliber of the bronchi. Exposure to passive stressors (e.g., watching stressful movies or pictures) was also associated with an increase in SNS responses and with mild bronchoconstriction. However, a paucity of data for passive stressors limited conclusions on other measures.

CONCLUSIONS: In patients with asthma, both active and passive stressors seem to be associated with an increased activation of the SNS. Passive stressors seem to have a more immediate, deleterious impact on the airways than active stressors, but the latter may be associated with delayed inflammatory driven an asthma exacerbation. Further studies are needed to understand the impact of acute stressors on the physiological mechanisms associated with asthma, particularly HPA and immune markers. Systematic review registration number: CRD42015026431.