Influence of the way of reporting alpha-Amylase values in saliva in different naturalistic situations: A pilot study

• Published in: PloS one Vol. 12; no. 6; p. e0180100
• Main Authors: Contreras-Aguilar, María Dolores, Escribano, Damián, Martínez-Subiela, Silvia, Martínez-Miró, Silvia, Rubio, Mónica, Tvarijonaviciute, Asta, Tecles, Fernando, Cerón, Jose J
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.06.2017; Public Library of Science (PLoS)
• Subjects: Adolescent; Amylases; Analysis; Assaying; Biology and Life Sciences; Enzyme Assays - methods; Female; Flow velocity; Fluoroimmunoassay - methods; Humans; Interdisciplinary aspects; Laboratories; Male; Medicine and Health Sciences; Methods; Monte Carlo simulation; Physical Sciences; Pilot Projects; Proteins; Research and Analysis Methods; Research Design; Saliva; Salivary alpha-Amylases - analysis; Social Sciences; Stress concentration; Stress response; Stress, Physiological - physiology; Stress, Psychological - metabolism; Students; Young Adult; α-Amylase; Spain
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0180100

The objective of this pilot study was to compare the different ways of measuring salivary alpha-amylase (sAA, enzymatic vs. concentration) and to evaluate the influence that the different ways of reporting the results can have in sAA interpretation. For this purpose, sAA was measured by direct quantification and also by an enzymatic assay in three different naturalistic situations, a physical stressor (situation 1) and two mental stressors of different intensity (situations 2 and 3). The results were expressed in three different ways (without correction, multiplied by flow rate and divided by protein concentration). sAA concentration and activity increased just after situations 1 and 3. When values were multiplied by the flow rate, significant changes after situation 1 were detected only for sAA activity but not for sAA concentration, being these changes of lower significance and magnitude that those observed for sAA activity without any correction. In addition, a significant increase in sAA activity was found at T+15 in situation 2. In situation 3 the significant decrease in sAA at T+15 disappeared. When values were divided by protein concentration, there were no significant changes in situations 1 or 3, but a decrease in situation 2 at T+0 and an increase at T+15. sAA activity and concentration showed a significant correlation in all situations. This pilot study points out that the way of expressing sAA can influence the results obtained in different stress models and also their interpretation. Therefore, how sAA is reported and the factors involved in the different ways of expressing sAA, should be taken into consideration for an objective interpretation of sAA values.