Basal levels of salivary chromogranin A, but not α‐amylase, are related to plasma norepinephrine in the morning

To evaluate the activity of sympatho–adrenomedullary (SAM) system, testing for salivary chromogranin A (CgA) and α‐amylase (sAA) has been receiving attention. We investigated the correlation between levels of plasma norepinephrine (NE) and salivary CgA or sAA. From 21 healthy males, blood and saliva samples were collected at 8:00, 10:30, 12:30 and 17:30. Levels of plasma NE, salivary CgA and sAA were determined at each sampling point. To avoid the influence of the salivary flow, resultant levels of salivary CgA and sAA were adjusted according to salivary flow rates and salivary protein, respectively. A significant correlation between plasma NE levels and salivary CgA/protein was detected in samples taken at 8:00 (p < 0.01). In samples taken at 10:30, 12:30 and 17:30, however, there was no such correlation. Meanwhile, no significant correlation between plasma NE levels and sAA/min was detected during the sampling period. These findings suggest that morning results for CgA may be useful as a predictor for SAM system activity.