Is there a relationship between periodontitis and Alzheimer's disease? Systematic review and comparative analysis

Abstract

Background: Alzheimer's disease is a neurodegenerative disease with unknown cause, being the first cause of dementia affecting 24 million people, which is set to double by 2040. Periodontitis is a multifactorial, inflammatory and chronic disease that causes the loss of the tooth's support system; being the number one cause of tooth loss in adults. Both diseases are highly prevalent, making them an important public health issue. New studies have shown that there might be a relation between them.Method: Systematic review and comparative analysis of studies through a bibliographic search that included clinical trials, case-control and cohort studies in humans, with objective tests for the diagnosis of both diseases. Excluding: descriptive studies or studies that didn't focus on Alzheimer's; studies that didn't diagnose periodontitis clinically; sigle case studies; based on patients with syndromes; or evaluated exclusively the quality of life of the patients. From the 473 articles found only 9 fulfilled the inclusion and exclusion criteria.Result: Out of the 9 articles selected, 7 found a statistically significant difference between people with Alzheimer's and without it in relation to periodontitis (Choi S et al, Ide M et al, de Suza T et al, Martande SS et al, Holmer J et al, Cestari JA at al, Aragón F et al). Chen CK et al didn't find a statistical significance at the beginning (p=0.0547) but did in the 10 years follow-up (p=0.00264). Tiisanoja A et al didn't find a statistic significance (RR=1.54; IC=0.52-4.56). However, when subjecting the article's results to CI for the proportion analysis we discovered that only one study found this difference significant out of the 6 included. Conclusion:The most common oral problems in patients with Alzheimer's were gingivitis, periodontitis, tooth loss, candidiasis, calculus. Although there seems to be a relationship between the two, further studies with larger populations and a better screening process for participants, are needed in order to truly assess whether there is a causal relationship between the two pathologies or not. One of the greatest limitations we encountered was the lack of homogeneity between the studies statistical tools, making it impossible to do a meta-analysis.

Relationship between periodontal diseases and non-specific inflammatory bowel diseases – an overview. Part I

“…According to the classification introduced in 2017 by the American Academy of Periodontology and the European Federation of Periodontology, periodontal diseases may be divided into 4 groups: 1) healthy periodontium, and diseases and changes in the gums; 2) periodontitis; 3) other disease states that may predispose to periodontal disease; 4) diseases and changes in the tissues around implants [16]. Periodontitis is closely related with several systemic diseases, including: atherosclerosis [17], diabetes [18], rheumatoid arthritis [19], and Alzheimer's disease [20].…”

The effect of the “Oral-Gut” axis on periodontitis in inflammatory bowel disease: A review of microbe and immune mechanism associations

“…There is a growing body of research showing that the health of oral tissues interacts with systemic health (Taylor et al, 2000;Genco and Sanz, 2020;Kapila, 2021;Larvin et al, 2022;Teles et al, 2022). Notably, periodontitis is closely associated with several systemic diseases, including atherosclerotic cardiovascular disease (Beck et al, 2001;Van Dyke et al, 2021;Isola et al, 2022), diabetes (Chapple et al, 2013;Genco and Borgnakke, 2020;Nibali et al, 2022), adverse pregnancy outcomes such as miscarriage and preterm delivery (Canakci et al, 2004;Sanz et al, 2013;Miranda-Rius et al, 2021), rheumatoid arthritis (Bartold and Lopez-Oliva, 2020;Möller et al, 2020;Gonzaĺez-Febles and Sanz, 2021), Alzheimer's disease (Pizza, 2019;Kamer et al, 2020;Torrealba-Garcıá et al, 2021) and inflammatory bowel disease (Cai et al, 2021;Imai et al, 2021;Zhang et al, 2021a;Baima et al, 2022).…”