Salivary thiocyanate levels among tobacco users, non-users, and passive smokers: A biochemical study

BACKGROUND an‎d AIM: The prevalence of tobacco use and its associated mortality is increasing worldwide. Biomarkers in saliva, such as thiocyanate levels, have been shown to be a suitable indicator for smoking. The present study is conducted to determine the thiocyanate levels in saliva and compare them among tobacco (smoking and smokeless) users, passive smokers, and non-smokers. METHODS: A cross-sectional comparative study was conducted on 100 patients attending a dental college in South India. The patients were inquired about their tobacco habits and were divided into 4 groups: smokers (25), passive smokers (25), smokeless tobacco users (25), non-users (25). Saliva samples were collected from subjects in sterile containers, and thiocyanate levels were estimated. The results were tabulated and analyzed using SPSS software. Kruskal-Wallis test was used for the intergroup comparison of salivary thiocyanate levels. Mann-Whitney U test was used for the pairwise group comparison. If P < 0.0500, the results were reported to be statistically significant. RESULTS: The results of the study showed that the salivary thiocyanate level was 79.46 ± 7.80, 50.16 ± 6.87, 50.16 ± 13.83, and 36.61 ± 5.84 mmol/l among smokers, passive smokers, smokeless tobacco users, and non-users, respectively. There was a statistically significant difference in salivary thiocyanate levels among various groups (P ≤ 0.0001). All pairwise comparisons showed statistical significance (P ≤ 0.0001) except the comparison between the passive smokers and smokeless tobacco users groups (P = 0.9200). CONCLUSION: Salivary thiocyanate may be a diagnostic biomarker for differentiating tobacco users from the non-users.