Tooth loss, periodontal disease, and cognitive decline in the Atherosclerosis Risk in Communities (ARIC) study.

OBJECTIVE: The purpose of this prospective study was to investigate whether poor oral health predicted 8-year cognitive function change in predominantly late middle adults in the Atherosclerosis Risk in Communities (ARIC) study. METHODS: Participants included a subset of ARIC participants aged 52-75 years at 1996-1998 from two study sites: Forsyth County NC and Jackson MS. All subjects completed cognitive function assessments both in 1996-1998 and 2004-2006, and the same subjects received a dental examination at the initial visit. Cognitive assessment consisted of delayed word recall (DWR), digit symbol substitution (DSS), and word fluency (WF) tests. In the analysis, cognitive function for 911 dentally screened participants was evaluated, and 558 of 785 dentate participants received comprehensive oral examinations, including periodontal probing. Measures of oral health included dental status, number of teeth, and periodontal disease classified by the biofilm-gingival interface (BGI) index. The generalized estimating equations (GEE) method was used to analyze repeated measures of cognitive scores with adjustment for socio-demographic characteristics and cardiovascular risk factors. RESULTS: Of 911 study participants, 13.8% were edentulous. About 13% of dentally examined participants had periodontal pockets (≥ 4 mm) with severe bleeding. At the follow-up visit, DWR and WF scores were lower in edentulous compared to dentate people, whereas other oral health measures were not associated with cognitive function. Mean values declined over time for all three cognitive measures, although poor oral health conditions were not associated with greater degree of decline in cognitive function. CONCLUSIONS: In these late middle-aged adults, complete tooth loss was significantly associated with lower cognitive performance. However, neither edentulism, number of teeth, nor periodontal disease predicted greater subsequent cognitive decline.

Cross-sectional associations of oral health measures with cognitive function in late middle-aged adults: a community-based study.

BACKGROUND: It has not been established to what extent oral health is associated with cognitive function in late middle-aged adults. In this study, which is part of the national Atherosclerosis Risk in Communities (ARIC) study, the authors investigated whether tooth loss and periodontitis are associated with lower cognitive function. METHODS: The authors analyzed ARIC data measuring cognitive function in 11,097 participants from 1996 through 1998 according to tests of delayed word recall, digit-symbol substitution (DSS) and word fluency; 9,874 participants answered dental screening questions. Of the 8,554 dentate participants, 5,942 received oral examinations. The authors used measures of dental status, number of teeth and periodontitis (classified according to the Biofilm-Gingival Interface Index) in multiple linear regression models to estimate these factors' cross-sectional association with cognitive scores, adjusting for sociodemographic factors, cigarette smoking, alcohol use and diabetes. RESULTS: Approximately 13 percent of participants were edentulous. Of the dentate participants, 27.3 percent had fewer than 20 teeth and 12.4 percent had pocket depth of 4 millimeters or more with severe bleeding. Compared with dentate participants, edentulous participants had lower scores for all cognitive tests. Among the dentate participants, having fewer teeth and gingival bleeding were associated with lower DSS and word fluency test scores, although periodontal pocket depth was not. CONCLUSIONS: In this cohort, edentulism was correlated with lower cognitive status. Tooth loss and gingival bleeding were markers of poorer executive function among dentate people. Practical Implications. The association of lower cognitive scores with edentulism suggests that past oral diseases may be a risk indicator for cognitive decline, whereas the association with gingival inflammation indicates a possible effect of cognitive decline on oral health. Practitioners should be aware that both current and historical markers of oral disease might be associated with decline in cognitive function, even in adults of late middle age.