Evaluation of salivary alkaline phosphatase levels in tobacco users to determine its role as a biomarker in oral potentially malignant disorders

BACKGROUND: Elevated salivary alkaline phosphatase (S-ALP) levels have been observed in oral squamous cell carcinoma, but its status in tobacco users and in individuals with oral potentially malignant disorders (OPMDs) is less explored. AIMS AND OBJECTIVES: The aims and objectives were to estimate and compare the levels of S-ALP among tobacco users, nonusers and in individuals with OPMD. MATERIALS AND METHODS: The study population comprised 42 individuals, categorized into four groups with/without tobacco usage habit and with/without lesion. 5 ml of unstimulated saliva sample was collected, centrifuged at 3000 rpm for 15 min and supernatant separated. S-ALP was estimated in the supernatant by using kinetic photometric method in an automatic analyzer. RESULTS: Data obtained were subjected to statistical analysis. The mean S-ALP was 18.00 IU/L for normal individuals without tobacco usage, 4.60 IU/L for smokers without lesion, 7.50 IU/L for tobacco chewers without any lesion and 64.90 IU/L for individuals with OPMD. The mean difference between the groups was statistically significant (P < 0.001) using Kruskal–Wallis’ ANOVA. No statistically significant difference (P > 0.05) was obtained in the S-ALP levels between tobacco users and nonusers and between smokers and tobacco chewers, using Mann–Whitney U-test. S-ALP levels in individuals with OPMD were statistically significantly higher (P < 0.001) than those without lesions, with or without tobacco usage habit, using Mann–Whitney U-test. CONCLUSION: We conclude that S-ALP could be used as a reliable noninvasive biomarker in monitoring OPMD.