Five-year follow-up study of the association between periodontal disease and myocardial infarction among Japanese male workers: MY Health Up Study.

BACKGROUND: An association between chronic oral infections and coronary heart disease has been suggested. METHODS: The study participants were male employees aged 36-59 years. Data were extracted from the MY Health Up Study, comprising a baseline questionnaire survey and succeeding annual health examinations for financial firm workers in Japan. Using a self-administered questionnaire at baseline, participants' oral status was classified into three types of periodontal indicators: (i) periodontal score, (ii) periodontitis and (iii) tooth loss (<5 and >/=5 teeth). An incidence of myocardial infarction (MI) was determined by annual health examination records. RESULTS: Of the 4037 candidates for follow-up in the baseline year of 2004, 3081 males were eligible for the analysis, 17 of whom experienced MI in the subsequent 5 years. The periodontal score model was associated with an increase in developing MI [odds ratio (OR) = 2.11, 95% confidence interval (CI) = 1.29-3.44], after adjusting for other confounding variables. The periodontitis (OR = 2.26, 95% CI = 0.84-6.02) and tooth loss (OR = 1.97, 95% CI = 0.71-5.45) models showed similar trends, although the difference was not significant. CONCLUSIONS: Periodontal disease may be a mild but independent risk factor for MI among Japanese male workers.