J‐shaped associations between thiocyanate and periodontitis: A cross‐sectional study from NHANES 2009–2014

Abstract Background This study aims to assess the associations between exposures to thiocyanate and the risk of periodontitis among US adults. Methods We conducted a cross‐sectional study using data from the National Health and Nutrition Examination Survey (NHANES) 2009–2014. We categorized periodontitis according to the 2017 classification scheme. Restricted cubic spline analysis and weighted multivariable logistic regression were employed to examine the relationship between thiocyanate exposure and periodontitis. Results A total of 3319 participants were included in our study. We observed a J‐shaped association between thiocyanate exposure and periodontitis, with an inflection point at 3.32. Before the inflection point, we noted a negative trend in the relationship between thiocyanate and periodontitis (odds ratio [OR] = 0.89, 95% CI: 0.73–1.08), particularly among smokers (OR = 0.31, 95% CI: 0.08–1.18). After the inflection point, we found a positive association (OR = 1.21, 95% CI: 1.03–1.42), particularly among non‐obese individuals (OR = 1.42, 95% CI: 1.16–1.75) and non‐hypertensive individuals (OR = 1.34, 95% CI: 1.12–1.61). Conclusion A J‐shaped relationship exists between thiocyanate exposure and periodontitis, indicating its complex role, and further prospective trials are necessary to confirm these findings. Plain language summary Thiocyanate, a compound prevalent in both the environment and dietary sources, can impact health through mechanisms that are either protective or detrimental. This study sought to investigate the specific relationship between thiocyanate exposure and periodontitis utilizing data from the National Health and Nutrition Examination Survey (NHANES). The findings reveal that both insufficient and excessive levels of thiocyanate exposure are linked to an increased risk of periodontitis, underscoring the critical importance of maintaining an optimal range of thiocyanate exposure for periodontal health.