Affiliations: [a] Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, NY, USA | [b] Department of Epidemiology and Health Promotion, New York University College of Dentistry, New York, NY, USA | [c] Copenhagen Gerontological Oral Health Research Center, School of Dentistry, University of Copenhagen, Copenhagen N, Denmark | [d] Department of Public Health and Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark | [e] Department of Public Health, University of Copenhagen, Danish Aging Research Centre, University of Aarhus, Odense and Copenhagen, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
Correspondence:
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Correspondence to: Angela Ruth Kamer, DDS, MS, Ph.D., NYU College of Dentistry, Department of Periodontology and Implant Dentistry, 345 East 24th Street, New York, NY 10010, USA. Tel.: +212 998 9868; Fax: +212 995 4603; E-mail: ark5@nyu.edu.
Abstract: Inflammation plays a significant role in Alzheimer's disease (AD) pathogenesis. Studies have shown that systemic, peripheral infections affect AD patients. Cognitive dysfunction is a consistent finding in AD and periodontal disease is a chronic, peripheral infection often resulting in tooth loss. We hypothesized that older adults with periodontal inflammation (PI) or many missing teeth would show impaired cognition compared to subjects without PI or with few missing teeth, and among subjects with PI, those with many missing teeth would show impaired cognition compared to those with few missing teeth. The effect of PI/tooth loss on cognitive function [measured by Digit Symbol (DST) and Block Design (BDT) tests] was assessed in 70-year old Danish subjects. We found: 1) subjects with PI obtained lower mean DST scores compared to subjects without PI (p < 0.05); 2) subjects with many missing teeth had lower mean DST and BDT scores compared to subjects with few missing teeth (p < 0.05); 3) the association of PI with DST and BDT scores was dependant on the number of missing teeth (interaction: p = 0.03 and p = 0.06); and 4) education and previous cognitive scores (age 50) were important covariates. Subjects with PI had significantly lower adjusted mean DST scores compared to subjects without PI. However for adjusted BDT, the significance held only for subjects with few missing teeth. No difference in the adjusted DST and BDT scores was seen between subjects with many missing teeth compared to those with few missing teeth. These results support the hypothesis that PI may affect cognition.
