Associations between salivary alpha-amylase and catecholamines - A multilevel modeling approach

Data from two studies were analyzed. In Study 1, 13 men were examined in a randomized repeated within-subjects double-blind study with yohimbine/placebo. In Study 2, 30 men were randomized in a repeated within-subjects design to psychosocial stress/rest. Associations of repeatedly assessed sAA, norepinephrine, and epinephrine in blood were analyzed using multilevel modeling. Over the time course, sAA was significantly associated with the catecholamines (Study 1: R2 = .43, Study 2: R2 = .09) and both served as mediators of sAA increases. Additional exploratory analyses suggest stronger associations during challenge/stress than during placebo/rest. These findings further support sAA as marker of sympathetic activity.