〈Originals〉The association between anxiety and a decline in saliva cortisol during interview stress in adult patients with asthma

[Abstract] The relationship between anxiety and asthma is currently being intensively studied. It has been demonstrated that there is reduced responsiveness of the hypothalamus-pituitaryadrenal (HPA) axis to psychosocial stress in an animal model of asthma. Our objectives were to identify the associations between anxiety and the decline of saliva cortisol during stress in adult patients with asthma. Saliva cortisol was sampled before and up to 30 min following stress induced by interviews in 30 adult patients with asthma, excluding known psychiatric patients. Anxiety was measured using the anxiety subscale of the Hospital Anxiety and Depression (HAD) scale. For interview stress, patients also completed the Asthma Control Test (ACT), theState/Trait Anxiety Inventory (STAI) for anxiety rating, and the 2006 questionnaire edited in a guideline for the diagnosis and treatment of psychosomatic diseases for diagnosing psychosomatic illness as asthma. The saliva cortisol levels were quantified by enzyme immunoassay. Clinically relevant anxiety (HADS score of 8) was indicated in 9 patients (30％) and depression in 4 (13％). Five patients (16.7％) had clinically significant state-anxiety scores of> 52, and seven patients (23.3％) had clinically significant trait-anxiety scores of> 55. Eight patients (26.7％) had been diagnosed as having psychosomatic asthma. The characteristics were similar between patients with and without anxiety, with the exception of age (P < 0.01) and ACT score (P <0.01). The changes in the ratio [(after stress-before stress)/before stress] of saliva cortisol were lower in patients with anxiety than in those without anxiety (-0.3±0.9 vs. 0.1+1.9, P < 0.05). In asthmatic patients with anxiety, there was a smaller interview stressinduced deterioration of saliva cortisol, which was consistent with reduced HPA axis activity