NYU dental researchers have found evidence that periodontal disease may increase the risk of cognitive dysfunction that is a consistent finding in Alzheimer's disease.
The study offers fresh evidence that periodontal inflammation may contribute to brain inflammation, neurodegeneration, and Alzheimer's disease.
The research team, led by Dr. Angela R. Kamer, Associate Professor of Periodontology & Implant Dentistry, examined data derived from 152 elderly subjects. "The research suggests that elderly subjects with periodontal inflammation are at an increased risk of lower cognitive function compared to subjects with little or no periodontal inflammation, and these results hold true even after considering the subjects' cognition 20 years ago," said Dr. Kamer.
Dr. Kamer's study, conducted in collaboration with Dr. Douglas E. Morse, Associate Professor of Epidemiology & Health Promotion at the NYU College of Dentistry, and a team of researchers in Denmark, builds on a 2008 study by Dr. Kamer which found that subjects with Alzheimer's disease had a significantly higher level of antibodies and inflammatory molecules associated with periodontal disease in their plasma compared to healthy people.
The findings are based on an analysis of longitudinal data on periodontal inflammation and cognitive function from the Glostrup Aging Study, which gathered medical, psychological, oral health, and social data on Danish men and women over a 20-year period ending in 1984, when the subjects were all 70 years of age. The findings were presented at the 2010 annual meeting of the International Association for Dental Research in Barcelona, Spain.
Dr. Kamer's team compared cognitive function at ages 50 and 70, using the Digit Symbol Test, or DST, a part of the standard measurement of adult IQ. The DST assesses how quickly subjects can link a series of digits, such as 2, 3, 4, to a corresponding list of digit-symbol pairs, such as 1/-,2/- ... 7/Λ,8/X,9/=.
Dr. Kamer found that periodontal inflammation at age 70 was strongly associated with lower DST scores at age 70. Subjects with periodontal inflammation were nine times more likely to test in the lower range of the DST compared to subjects with little or no periodontal inflammation.
This strong association held true even in those subjects who had other risk factors linked to lower DST scores, including obesity, education, hypertension, cardiac ischemia, and cigarette smoking. The strong association also held true in those subjects who already had a low DST score at age 50.
Dr. Kamer plans to conduct a follow-up study involving a larger, more ethnically diverse group of subjects, to further examine the connection between periodontal disease and low cognition.
In addition to Dr. Morse, Dr. Kamer's coinvestigators included Dr. Poul Holm-Pedersen, Professor and Director of the Gerontology & Oral Health Research Center; Dr. Erik Lykke Mortensen, Professor of Psychology; and Dr. Birita Ellefsen, Assistant Professor of Gerontology & Oral Health, all at University of Copenhagen in Denmark; and Dr. Kirsten Avlund, Professor of Social Medicine at the Institute of Public Health in Copenhagen.