Abstract
Background: Salivary diagnostics promise an easily accessible, non-invasive approach for analyzing and monitoring various oral diseases including cancer. Objectives: This study was undertaken to establish the baseline salivary lactate dehydrogenase (LDH) levels in healthy controls and to discern the effect of smokeless tobacco (SLT) on the diagnostic efficacy of salivary LDH. Materials and Methods: Thirty-seven systemically and periodontally healthy individuals in the age group of 19-27 years without any deleterious habit and oral lesion participated in this study. After explaining the procedure to the participants, unstimulated whole saliva was collected by spit method under sterile conditions. Baseline LDH activity was measured spectrophotometrically. After evaluating baseline activity, 1 ml of saliva was mixed with 1 g of SLT and incubated at 37°C. LDH activity was measured at different time intervals. Results: The median value of baseline LDH levels at rest was 338 IU/L. The gender-based variation in LDH activity was found to be non-significant. Exposure of whole saliva to SLT resulted in an initial increase followed by reduction in the LDH activity. Conclusion: This study provides additional rationale for the use of salivary LDH as a biomarker to investigate the aggressiveness and biological nature of oral pathological conditions. Interpretation of changes in salivary LDH activity should be done with caution in individuals habituated to tobacco use.