Periodontitis Increases the Risk of a First Myocardial Infarction: A Report From the PAROKRANK Study.

BACKGROUND: The relationship between periodontitis (PD) and cardiovascular disease is debated. PD is common in patients with cardiovascular disease. It has been postulated that PD could be causally related to the risk for cardiovascular disease, a hypothesis tested in the Periodontitis and Its Relation to Coronary Artery Disease (PAROKRANK) study. METHODS AND RESULTS: Eight hundred five patients (<75 years of age) with a first myocardial infarction (MI) and 805 age- (mean 62±8), sex- (male 81%), and area-matched controls without MI underwent standardized dental examination including panoramic x-ray. The periodontal status was defined as healthy (≥80% remaining bone) or as mild-moderate (from 79% to 66%) or severe PD (<66%). Great efforts were made to collect information on possibly related confounders (≈100 variables). Statistical comparisons included the Student pairwise t test and the McNemar test in 2×2 contingency tables. Contingency tables exceeding 2×2 with ranked alternatives were tested by Wilcoxon signed rank test. Odds ratios (95% confidence intervals) were calculated by conditional logistic regression. PD was more common (43%) in patients than in controls (33%; P<0.001). There was an increased risk for MI among those with PD (odds ratio, 1.49; 95% confidence interval, 1.21-1.83), which remained significant (odds ratio, 1.28; 95% confidence interval, 1.03-1.60) after adjusting for variables that differed between patients and controls (smoking habits, diabetes mellitus, years of education, and marital status). CONCLUSIONS: In this large case-control study of PD, verified by radiographic bone loss and with a careful consideration of potential confounders, the risk of a first MI was significantly increased in patients with PD even after adjustment for confounding factors. These findings strengthen the possibility of an independent relationship between PD and MI.

Do genetic factors explain the association between poor oral health and cardiovascular disease? A prospective study among Swedish twins.

Epidemiologic studies suggest positive associations between poor oral health and cardiovascular disease. The authors undertook a prospective study among 15,273 Swedish twins (1963-2000) to examine whether genetic factors underlying the 2 diseases could explain previous associations. They estimated hazard ratios and 95% confidence intervals controlling for individual factors and stratifying on twin pairs to control for familial effects. Quantitative genetic analyses estimated genetic correlations between oral diseases and cardiovascular disease outcomes. Tooth loss (hazard ratio (HR) = 1.2, 95% confidence interval (CI): 1.1, 1.4) and periodontal disease (HR = 1.3, 95% CI: 1.0, 1.4) were associated with small excess risks of cardiovascular disease; periodontal disease was also associated with coronary heart disease (HR = 1.4, 95% CI: 1.1, 1.6). Adjustment for genetic factors in co-twin analyses did not appreciably change estimates. In contrast, tooth loss was more strongly associated with coronary heart disease in twin models (HR = 2.1, 95% CI: 1.2, 3.8) compared with adjusting for individual factors alone (HR = 1.3, 95% CI: 1.1, 1.4). There was evidence of shared genetic factors between cardiovascular disease and tooth loss (r(G) = 0.18) and periodontal disease (r(G) = 0.29). Oral disease was associated with excess cardiovascular disease risk, independent of genetic factors. There appear to be common pathogenetic mechanisms between poor oral health and cardiovascular disease.