Association of Alzheimer’s disease and periodontitis - a systematic review and meta-analysis of evidence from observational studies

The relationship between periodontitis (or periodontal disease) with Alzheimer’s disease has been reported by various primary sources in the past decade, but not with a solid secondary research statement. A systematic review and meta-analysis was conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and registered (Reference number: CRD42020185264) with PROSPERO (International prospective register for systematic reviews). A literature search was conducted on specific databases for suitable articles in English language. Out of 612 studies selected, 41 underwent full-text analysis; five studies were eligible for systematic review, and 3 for meta-analysis. Meta-analysis was performed with tests for sensitivity and statistical heterogeneity followed by calculation of summary effect measures in terms of odds ratio (OR) and 95% confidence interval (CI). The results of this review showed a significant association between periodontitis and Alzheimer’s disease in the meta-analysis [OR 1.67 (1.21–2.32)].