Association Between Periodontitis and Amyloid β Peptide in Elderly People With and Without Cognitive Impairment

Evidence that periodontal disease is a possible risk factor for cognitive impairment may be explained by the inflammatory hypothesis. The aim of this study is to determine whether periodontitis is related to the amyloid β (Aβ) load in blood and the role of any such relationship in the association between Aβ and cognitive impairment.

A case-control study was performed in elderly people diagnosed with cognitive impairment with or without dementia (cases group) and cognitively healthy elderly people (control group); data were collected on the medical and dental history of participants, and blood samples were drawn to determine Aβ levels using enzyme-linked immunosorbent assay.

The study included 166 patients and 122 control participants. Higher blood Aβ_1-42 levels (P = 0.01) and higher Aβ_42:40 ratio (P = 0.06) were observed in participants with severe attachment loss than in other participants. Periodontitis was a significant interaction variable, given that the association between Aβ_1-42 and Aβ_1-40 and cognitive impairment was only observed in patients with severe periodontitis. According to these data, periodontitis may be a modulating variable of the association between Aβ and cognitive impairment.

Plasma Aβ_1-42 levels are higher in individuals who have severe periodontal disease. The presence of periodontitis may modify the association between Aβ and cognitive impairment.