Influence of saliva flow rate stimulated by gum-chewing on salivary concentrations of catecholamine metabolites

► Change in saliva flow rate may affect the accuracy of salivary HVA and MHPG assays. ► Variation in their salivary concentrations due to gum-chewing was measured using LC/ESI-MS/MS. ► Salivary concentrations significantly decreased when salivation was stimulated. ► Stimulated saliva should be used with caution in the measurement of the catecholamine metabolites.