Background: Data on biological variation in saliva samples are quite limited. This study aimed to obtain well-defined biological variation data for seven common clinical chemistry analytes and Trolox equivalent antioxidant capacity (TEAC) in saliva.
Methods: Unstimulated whole saliva and blood samples were collected from thirty-two healthy volunteers of both genders without any history of disease or metabolic syndrome under standard conditions at six different times within three weeks. The seven clinical chemistry analytes and TEAC, analyzed by photometric methods using automated analyzers, were planned for biological variation analysis. The components of nested analysis of variance were used to perform the biological variation data analysis.
Results: The within-subject and between-subject biological variations (CVG and CVI, respectively) for unstimulated whole saliva samples, respectively, were determined to be 19.3% and 25.1% for α-amylase, 25.1% and 51.1% for aspartate aminotransferase, 31.0% and 22.3% for lactate dehydrogenase, 19.0% and 20.8% for uric acid, 16.6% and 23.4% for total calcium, 12.9% and 13.7% for inorganic phosphate, 13.1% and 19.7% for total protein, and 14.9% and 20.0% for TEAC. In addition, the CVI and CVG were 3.4% and 6.3% for serum TEAC.
Conclusions: Considering the evidence that saliva samples can be used to diagnose and monitor oral or non-oral diseases, these biological variation data will contribute to how to use subject-based reference values or population-based reference intervals of these analytes and TEAC.