title: Salivary alpha-amylase and cortisol responsiveness following electrically stimulated physical stress in bipolar disorder patients.
abstract: BACKGROUND
  Bipolar disorder (BP) is often associated with a change in hypothalamus- pituitary-adrenal axis function change due to chronic stress. Salivary α-amylase (sAA) levels increase in response to psychosocial stress and thus function as a marker of sympathoadrenal medullary system activity. However, sAA has been studied less often than salivary cortisol in BP patients.
  
  
  METHODS
  We measured Profile of Mood States and State-Trait Anxiety Inventory scores, heart rate variability, and salivary cortisol levels during electrical stimulation stress in 25 BP patients and 22 healthy volunteers.
  
  
  RESULTS
  Tension-anxiety, depression-dejection, anger-hostility, fatigue, and confusion scores in BP patients significantly increased compared with those of the healthy controls. In contrast, the vigor scores of BP patients significantly decreased compared with those of the healthy controls. Significant difference in the sAA levels was observed between BP patients and healthy controls. sAA of female patients was significantly higher than that of female healthy controls, and sAA in male patients tended to be higher than that of male healthy controls. No difference in salivary cortisol was observed between BP patients and the healthy controls. Only three time points were measured before and after the electrical stimulation stress. Furthermore, sAA secretion by BP patients increased before and after electrical stimulation.
  
  
  CONCLUSIONS
  These preliminary results suggest that sAA may be a useful biological marker for BP patients.
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Maruyama
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Ishitobi
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Aimi
authors.initials: A
authors.lastname: Kawano
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ando
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Ikeda
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Ayako
authors.initials: A
authors.lastname: Inoue
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Imanaga
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Shizuko
authors.initials: S
authors.lastname: Okamoto
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanehisa
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Taiga
authors.initials: T
authors.lastname: Ninomiya
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Jusen
authors.initials: J
authors.lastname: Tsuru
authors.affiliation: Department of Neuropsychiatry, Faculty of Medicine, Oita University, Hasama-Machi, Oita, Japan.
authors.forename: Jotaro
authors.initials: J
authors.lastname: Akiyoshi
keywords: HPA axis; SAM activity; bipolar disorder; cortisol; α-amylase