Association between periodontitis and cognitive impairment among Korean elders

Abstract

Objectives: The association between cognitive impairment and periodontitis remains controversial. No study has yet reported on the link between periodontitis and cognitive functioning in Korean elderly population. Hence, this study aims to investigate the association between periodontitis and cognitive impairment among Korean elders. Methods: This study was set in the Yangpyeong cardiovascular cohort (YCC), a part of the Korean Genome Epidemiologic Study (KoGES), Yangpyeong, South Korea. This study is a cross-sectional study with age and sex matched case-control selection. From the YCC, 65 cognitive impairment cases and 124 normal controls (aged 60 or more) participated in this study. Alveolar bone loss was assessed on dental panoramic radiographs to categorize the cumulative history of periodontitis (HOP). HOP was dichotomized as non severe versus severe periodontitis (≥2 interproximal sites with RABL ≥6mm) and categoraized into three groups according to severity of periodontitis: normal, moderate periodontitis (≥2 interproximal sites with RABL ≥4mm) and severe periodontitis (≥2 interproximal sites with RABL≥6mm). Mini-Mental State Examination (MMSE) test was used to categorize the participants as either normal or cognitively impaired. For analysis, age-and sex-matched conditional logistic regression models were used. Confounders considered in the analysis include: age, sex, drinking, smoking, exercise, total cholesterol, total protein, body mass index defined obesity, fasting plasma glucose, intima-media thickness, hypertension medication and depression. Results: Participants with HOP were more likely to have cognitive impairment (odds ratio [OR] = 2.14, 95% confidence interval [CI] =1.04-4.41) than those without HOP. Interaction effect of smoking and exercise on periodontitis highlighted the link. Conclusion: Periodontitis was independently associated with cognitive impairment after controlling for various confounders. Further longitudinal research is needed to determine whether periodontitis plays a role in cognitive decline among older adults.