Association between periodontal condition and blood pressure is confounded by smoking

To investigate the role of smoking as a confounding factor in the association between periodontal pocketing and blood pressure.

After restriction to 45-64-year-old subjects without hypertension, diabetes, rheumatic diseases, obesity and with no history of cardiovascular diseases or ongoing lipid-lowering medications, the study population consisted of 307 subjects of the Health 2000 Survey in Finland. Systolic and diastolic blood pressure and pulse pressure (mmHg) were used as outcome variables. Periodontal condition was measured by the number of teeth with ≥4 mm periodontal pockets. β-estimates and 95% confidence intervals (CI) were obtained from linear regression models. Analyses were made in the whole study population and stratified according to smoking habits/history.

The number of teeth with ≥4 mm periodontal pockets associated statistically significantly with systolic blood pressure and pulse pressure in the whole study population. Among never-smokers or daily smokers, there were no consistent nor statistically significant associations between the number of teeth with ≥4 mm periodontal pockets and systolic/diastolic blood pressure or pulse pressure.

Smoking appeared to confound the association between periodontal condition and blood pressure. Thorough control for the effect of smoking was not obtained using multivariate models.