The association between poor dental health and depression: findings from a large-scale, population-based study (the NHANES study).

Objective: To examine the relationship of poor dental health and depression, controlling for markers of inflammation (C-reactive protein; CRP) and adiposity (body mass index; BMI).
Method: Data from two National Health and Nutrition Examination Surveys (2005-2008) were utilized (n=10214). Dental health was assessed using the Oral Health Questionnaire (OHQ). Depression was measured using the Patient Health Questionnaire-9 (PHQ-9), where cases were identified using a cut off score of 10 or above. Logistic regression was applied to measure magnitude of associations, controlling for a range of covariates including CRP and BMI.
Results: After adjustment for covariates, a significant dose-response relationship between number of oral health conditions and likelihood of PHQ-9 defined depression was observed. Compared with individuals without an oral health condition, adjusted odds ratio (95% confidence interval) for depression in those with two, four and six conditions were 1.60 (1.08-2.38), 2.13 (1.46-3.11) and 3.94 (2.72-5.72), respectively. Level of CRP and being underweight or obese were associated with being depressed.
Conclusions: A positive association exists between poor dental health and depression that is independent of CRP and BMI.
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