State cigarette excise tax, secondhand smoke exposure, and periodontitis in US nonsmokers

Objectives: We assessed the relationship of state cigarette excise tax with cigarette sales, secondhand smoke (SHS) exposure, and periodontitis among US lifetime nonsmokers. Methods: Cigarette excise tax and per capita sales data from 1983 to 1998 were obtained for 50 states and the District of Columbia. Periodontal data were analyzed for 3137 adults in 28 states from 3 National Health and Nutrition Examination Survey cycles (1999-2004). Measures of periodontal pocket depth and attachment level were used to classify people with moderate or severe periodontitis. SHS exposure was classified according to gender- or race/ethnicity-specific thresholds of serum cotinine concentration. Statistical analysis adjusted for the complex survey design. Results: For each additional $0.10 in excise tax, predicted sales decreased by 0.74 packs per person per month and adjusted odds of moderate or severe periodontitis decreased 22% (odds ratio [OR] = 0.78; 95% confidence interval [CI] = 0.62, 0.97). For each pack sold per person per month, adjusted odds of SHS exposure increased 28% (95% CI = 1.17, 1.40) and adjusted odds of periodontitis increased 15% (95% CI = 1.03, 1.29). Odds of periodontitis for those exposed to SHS were elevated 2-fold relative to those who were unexposed (OR = 2.03; 95% CI = 1.30, 3.20). Conclusions: Cigarette excise tax may protect nonsmokers against periodontitis.