Estimation of salivary lactate dehydrogenase in oral squamous cell carcinoma, oral leukoplakia, and smokers.

Abstract

Lactate dehydrogenase (LDH) is an enzyme seen within every cell during their normal metabolic function. It is always confined within the cell cytoplasm and it becomes extracellular only when a cell dies. The extracellular presence of LDH is related to cell necrosis and tissue breakdown. Therefore, we designed a study to estimate and compare LDH levels in the saliva of patients with oral cancer, oral leukoplakia (OL), and smokers without lesions and in controls. A total of 81 subjects of both genders, between the ages of 20 and 70 years, were included in the study. The study group was divided into four: group I-controls (n = 20), Group II-smokers (n = 20), Group III-subjects with OL (n = 20), and Group IV-subjects with oral squamous cell carcinoma (OSCC) (n = 21). Five milliliters of unstimulated salivary sample was collected from each participant, and salivary LDH level was measured. The obtained values were tabulated and statistically analyzed. P < 0.05 was considered to be statistically significant. The difference in LDH levels among the four groups was found to "BE" statistically significant. LDH values showed a marked increase in the leukoplakia group (49.79 ± 19.88 IU/L) and OSCC group (106.97 ± 32.75 IU/L) when compared to controls and smokers. We found that salivary LDH was increased in patients with leukoplakia and OSCC. Smoking alone did not produce any alterations in salivary LDH. It is possible that salivary LDH could be a potential biomarker to identify early premalignant or malignant changes in smokers.