Clinical Significance of Salivary Alpha-amylase Activity in Patients With Parkinson's Disease

Salivary alpha-amylase (sAA) is known as a stress indicator for the general adult population. However, its clinical significance has not been established in patients with neurodegenerative diseases. The subjects consisted of the PD group (n = 146), the control (C) group (n = 109) and the age-matched control (AC) group (n = 79). We explored what clinical indicators are associated with sAA in patients with Parkinson's disease (PD). Results of factor analysis and stepwise multiple linear regression analysis demonstrated that NRS remained as the only factor related to sAA (p < 0.05). However, sAA was strictly related to age in the two control groups (p < 0.01). There was no significant difference in sAA between the PD and AC groups (p < 0.05). The results indicated that sAA could be an indicator of mental stress in patients with PD. In contrast, in the C group, sAA seemed to be mainly influenced by sympathetic tone associated with ageing.