While the positive effects of pulmonary rehabilitation (PR) are known, the effect of PR exercise on biobehavioral outcomes related to stress (cortisol) and immune function (IgA) has not been described. This study provides the initial evaluation of the effect PR exercise on stress and mucosal immunity in PR patients.
Purpose:
To describe changes in the biobehavioral outcomes related to stress and mucosal immunity during a single exercise session of PR in patients participating in PR.
Methods:
A total of 29 subjects (17 males, 12 females) with COPD (n = 25; FEV1 % predicted 43.9 +/- 18.4; FEV1/FVC ratio 49.4 +/- 13.6) and pulmonary fibrosis(n = 4; FVC predicted 77.2 +/- 23.2; FEV1 % predicted 88.2 +/- 25.6; FEV1/FVC ratio 82.5 +/- 4.5) were enrolled. Subjects were excluded for corticosteroid or antibiotic use within the past month. Baseline demographics, PFT, height, weight and hip-waist measurements were collected. Saliva samples via passive drool were collected for salivary cortisol and IgA pre- and post-exercise.
Results:
All subjects were at completion of the formal program or in maintenance program, indicating acclimation to exercise. No significant differences were seen between time of PR session (P = 0.131). The cortisol and IgA data was found to be non-normal, so the Wilcoxon Signed Ranks test for related samples was used. A significant reduction was seen in Cortisol (Z = -3.144, P = 0.002) from pre- to post-exercise. However, no significant change was seen for IgA (Z = -1.373, P = 0.17), but the direction of change was inverse to cortisol, as expected. BMI was not significantly correlated with pre-cortisol (P = 0.061) or post-cortisol (P = 0.064). Waist -hip ratio also was not significantly correlated with pre-cortisol (P = 0.171) or post-cortisol (P = 0.171).
Conclusion:
These findings support that a single session of PR significantly impacts both salivary cortisol in PR participants who have consistently participated in formal and maintenance PR. The direction of the change seen in cortisol and IgA were consistent with those seen in persons acclimated to exercise.