The pro-inflammatory cytokines, salivary cortisol and alpha-amylase are associated with generalized anxiety disorder (GAD) in patients with asthma

Generalized anxiety disorder (GAD) is common in patients with asthma. High levels of GAD may lead both to exacerbation of the condition and poor management. However, the physiological mechanisms of GAD in asthma patient is unclear. This study investigated the associations between the diurnal rhythm of sputum cytokines, salivary cortisol, α-amylase and GAD in asthma patients. Patients with co-morbid GAD and asthma showed higher sputum IL-1 AUC, sputum IL-6 AUC and sAA AUC. And there were positive correlations between Hamilton anxiety scale (HAMA) scores and sputum IL-1 AUC concentrations (r = 0.37, P = 0.002), HAMA scores and sputum IL-6 AUC (r = 0.56, P < 0.001), HAMA scores and sAA AUC (r = 0.75, P < 0.001). Also, there were positive correlations between Sputum IL-1 AUC and sAA AUC (r = 0.40, P < 0.001), between Sputum IL-6 AUC and sAA AUC. Stepwise multiple regression analyses showed the combination of sputum sAA AUC, IL-1 AUC, IL-6 AUC and cortisol AUC was the best predictor of HAMA scores (ΔR2 = 0.439, F(4,63) = 14.086, p < 0.001). Therefore, pro-inflammatory cytokines, salivary cortisol and alpha-amylase may all be involved in the occurrence of GAD in asthma patients.