Is Periodontal Disease a Partial Mediator of the Association Between Depressive Symptoms And Cardiovascular Disease?

Abstract

Epidemiological studies suggest that depression may be an independent risk factor for cardiovascular disease (CVD). Although several possible mediators of this association have been proposed, the precise mechanisms are yet unknown. Accordingly, we examined periodontal disease as a novel mediator of the depression-CVD association, given its separate links with both depression and CVD. Data from the National Health and Nutrition Examination Survey (NHANES) I and its Epidemiologic Follow-up Study (NHEFS) were analyzed. Participants were 3,346 individuals aged 25-74 years free of CVD at baseline (53% female, 16% non-white). Depression was assessed by the, depressed mood subscale of the General Well-Being Schedule Based on the Russell Periodontal Index, periodontal disease (43%) was defined as the presence of four or more periodontal pockets identified by a licensed dentist during an examination. The primary outcome was incident CVD (n=727, 22%), defined as nonfatal or fatal coronary artery disease or cerebrovascular disease, identified during the follow-up period by interviews and death certificate records. All analyses were adjusted for demographic and cardiovascular risk factors. Logistic regression analyses revealed no association between the GWBS depressed mood score and periodontal disease (OR=1.05, 95% CI: 0.96-1.14, p=.24). Cox proportional hazard models revealed that both periodontal disease (HR=1.24, 95% CI: 1.06-1.46, p=.009) and depressed mood (HR=1.08, 95% CI: 1.01-1.17, p=.03) were significant predictors of incident CVD. However, Sobel analyses found that periodontal disease was not a partial mediator of the depressed mood-incident CVD association (t=1.01, p=.31). Overall, these mediation results suggest that (a) both periodontal disease and depressed mood are independent predictors of incident CVD and that (b) the effect of depressive symptoms on incident CVD is not mediated by periodontal disease.