Cross-sectional associations of oral health measures with cognitive function in late middle-aged adults

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.