REVIEW PERIODONTITIS AS A RISK FACTOR FOR DEMENTIA: A SYSTEMATIC REVIEW AND META-ANALYSIS

Introduction The association between periodontitis and dementia remains controversial. Therefore, we analyzed this association focusing on the severity of periodontitis and type of dementia. Methods We searched the PubMed, Embase, Web of Science, and gray literature (Open- Grey, ProQuest) databases from inception to June 30, 2021, and pooled the data for meta-analysis. Fixed- or random-effects models were employed to calculate odds ratios (ORs), hazard ratios (HRs), and 95% confidence intervals (CIs) to evaluate the strength of the associations between periodontitis and dementia. Results Thirteen case-control and 11 cohort studies were selected. The analysis of entire studies indicated an association between periodontitis and dementia, with an OR of 2.26 (95% CI, 1.65-3.09; P < .0001) and HR of 1.15 (95% CI, 1.04-1.27; P = .0006). According to periodontitis severity, the risk of dementia was significantly associated with severe periodontitis (OR = 2.85; 95% CI, 2.16-3.74; P = .038), but not with less-than-moderate periodontitis (OR = 0.94; 95% CI, 0.64-1.40; P = .66). In particular, patients with severe periodontitis had a 6.87- fold higher risk of Alzheimer's dementia (OR = 6.87; 95% CI, 2.55-18.54; P = .04) and 2.92-fold higher risk of cognitive impairment (OR = 2.92, 95% CI, 2.15-3.96; P = .36). Conclusions We found a strong association between periodontitis and dementia, with severe periodontitis identified as a potential risk factor for Alzheimer's dementia. Therefore, timely management of periodontitis to prevent its progression may help prevent dementia.