Smoking induced heavy metals and periodontitis: findings from the Korea National Health and Nutrition Examination Surveys 2008-2010

Aim: Exposure to hazardous heavy metals such as cadmium and lead may contribute to increased oxidative stress and inflammation in the periodontal tissue. We aimed to evaluate the association between serum cadmium and lead levels and periodontitis. Materials & Methods: Pooled cross-sectional data from the Korea National Health and Nutrition Examination Surveys 2008-2010 were used. Periodontitis was defined as WHO community periodontal index. Active smokers were defined as self-reported current smokers or those with measured urine cotinine 164ng/ml measurements. Serum cadmium and lead levels were measured using graphite furnace atomic absorption spectrometry. Multiple logistic regression analysis was used to estimate the odds ratios (OR) for periodontitis. Results: The mean cadmium and lead levels were significantly higher in the periodontitis group compared with control population. A progressive increase in serum heavy metals were found as the number of sextants with periodontitis. The ORs for periodontitis were significantly associated with serum cadmium (OR = 1.37; 95% CI 1.00-1.87) and lead levels (OR = 1.60; 95% CI 1.15-2.21). The association between periodontitis and smoking was attenuated after adjusting for serum cadmium concentration. Conclusions: We demonstrated a significant association between periodontitis and serum cadmium and lead concentrations. Cadmium appeared to partially mediate the association between smoking and periodontitis.