Mediating role of systemic inflammation in the association between heavy metals exposure and periodontitis risk

Abstract

BackgroundThis study evaluated the mediating role of systemic inflammation in the association between exposure to heavy metals and periodontitis in a nationwide sample of adults.MethodsPooled cross‐sectional data from the National Health and Nutrition Examination Survey (NHANES 2009‐2014) were used (n = 8993). Periodontitis was defined by a full‐mouth examination and classified as no/mild and moderate/severe (mod/sev) groups. Blood and urinary heavy metal levels were investigated, including cadmium (Cd), lead (Pb), and mercury (Hg). In addition, systemic inflammation was assessed using circulatory leukocyte counts and C‐reactive protein (CRP) levels.ResultsMultivariable logistic regression analysis revealed the positive associations of blood and urinary levels of Cd and Pb with mod/sev periodontitis. In contrast,blood Hg levels did not show a significant association. The odds of having periodontitis were 1.233 and 1.311 times higher for each one‐unit increment in Ln‐transformed blood Cd (95% confidence interval [CI]: 1.109–1.371) and Pb (95% CI: 1.170‐1.470), respectively. Mediation analysis suggested a 6.3% to 11.5% contribution of leucocyte counts in the association of blood Cd and Pb levels with periodontitis. Sensitivity analyses for urinary Cd levels yielded consistent mediating effects. However, no significant mediating effect of CRP was detected.ConclusionHigher exposures to Cd and Pb were positively associated with periodontitis risk. These associations might be partially mediated by the elevated levels of leukocytes rather than CRP. Further longitudinal studies are needed to elucidate the discordant results of the systemic inflammatory biomarkers.

Association between blood ethylene oxide levels and periodontitis risk: a population-based study

“…Although NHANES analytical protocol recommended combine different cycles to recruit more participants and improve the stability of data estimates, we only select NHANES 2013–2014 because only this cycle documented full information on both HbEO and periodontitis ( 53 ). Although the association between ethylene oxide exposure and periodontitis could be affected by other environmental pollutant exposure, such as heavy metals and multiple polyaromatic hydrocarbons ( 54 , 55 ), we could not consider these above due to limited participant number. And we did not classify the severity of periodontitis in our statistical analysis due to limited number of participants.…”

Association of individual and combined exposures of 10 metals with periodontitis: Results from a large population‐based study

“…[41][42][43] Prior evidence based on population studies has demonstrated a correlation between cadmium metabolite levels and periodontitis. 12,[44][45][46] Furthermore, an animal study conducted experimentally has identified a significant influence of cadmium on periodontal bone, thereby suggesting its potential contribution to periodontal disease in humans. 15 Given that periodontitis is a disease with a cumulative effect on alveolar bone loss, we cannot rule out the hypothesis of a possible existing accidental association based on the cumulative effects of both factors, which needs to be further explored in the future.…”

“…Firstly, in this study, three main models (multiple logistic regression, BKMR and WQS) were used to explore the association between blood metals and periodontitis, which make the results more comprehensive. Second, while a recent study touched on a similar topic, 46 it primarily focused on the individual analysis of three metals. In contrast, our research incorporated a broader range of metals (10 types) and employed two statistical methods to assess the combined effects of these metallic elements, emphasizing the role of metal mixtures.…”