Alzheimer's disease and periodontitis - an elusive link

Abstract

Alzheimer's disease is the preeminent cause and commonest form of dementia. It is clinically characterized by a progressive descent in the cognitive function, which commences with deterioration in memory. The exact etiology and pathophysiologic mechanism of Alzheimer's disease is still not fully understood. However it is hypothesized that, neuroinflammation plays a critical role in the pathogenesis of Alzheimer's disease. Alzheimer's disease is marked by salient inflammatory features, characterized by microglial activation and escalation in the levels of pro-inflammatory cytokines in the affected regions. Studies have suggested a probable role of systemic infection conducing to inflammatory status of the central nervous system. Periodontitis is common oral infection affiliated with gram negative, anaerobic bacteria, capable of orchestrating localized and systemic infections in the subject. Periodontitis is known to elicit a "low grade systemic inflammation" by release of pro-inflammatory cytokines into systemic circulation. This review elucidates the possible role of periodontitis in exacerbating Alzheimer's disease. Periodontitis may bear the potential to affect the onset and progression of Alzheimer's disease. Periodontitis shares the two important features of Alzheimer's disease namely oxidative damage and inflammation, which are exhibited in the brain pathology of Alzheimer's disease. Periodontitis can be treated and hence it is a modifiable risk factor for Alzheimer's disease.

Epidemiology of periodontal diseases in Indian population since last decade

“…Recent epidemiologic, microbiologic, and inflammatory findings strengthen this association. [ 23 ] The association of periodontitis and peptic ulcers appeared largely consistent for gastric and duodenal ulcers as well as H. pylori -positive and H. pylori -negative ulcers. These observed associations persisted even after adjusting for putative risk factors, including smoking, alcohol intake, and regular use of aspirin and nonsteroidal antiinflammatory drugs (NSAIDs).…”

Association of Periodontitis and Subsequent Depression

“…6 , 18 Periodontitis is a disease showing low-grade systemic inflammation and releasing proinflammatory cytokines, including IL-1β, IL-6, and TNF-α, into systemic circulation. 19 Furthermore, psychological stress in patients with periodontitis exhibited a disturbed HPA axis and related hypercortisolism, which affects immune dysfunction and neuroinflammation and may result in subsequent development of depression. 20 , 21 By contrast, proinflammatory cytokines could induce indoleamine 2,3-dioxygenase secretion reducing the availability of tryptophan and disturbing serotonin synthesis.…”

Identification of Key Genes Related with Alzheimer’s Disease Treatment Through Bioinformatics Analysis

“…AD, the dominant cause and common form of dementia, is featured by a gradual decent in cognition, which occurs with memory degradation (Gurav, 2014). Tg2576 mice are the common animal models of AD (Sooy et al, 2015).…”