Research Paper Volume 13, Issue 18 pp 22571—22587
Helicobacter pylori infection and risk for developing dementia: an evidence-based meta-analysis of case-control and cohort studies
- 1 Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
- 2 Beijing University of Traditional Chinese Medicine, Beijing, China
- 3 Wangjing Hospital, China Academy of Chinese Medical Sciences, Beijing, China
Received: May 2, 2021 Accepted: August 23, 2021 Published: September 24, 2021https://doi.org/10.18632/aging.203571
How to Cite
Copyright: © 2021 Liu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Background: Infection with multiple pathogens may play a key role in the pathogenesis of dementia. Whether Helicobacter pylori (H. pylori) infection is associated causally with dementia is controversial.
Objective: We conduct a meta-analysis of case-control and cohort studies on the association between H. pylori infection and the risk for all-cause and Alzheimer’s disease (AD) dementia.
Methods: Two independent reviewers searched the PubMed, Cochrane Library, and Embase databases with English language restrictions from the date of conception to September 18, 2020. The primary analysis was as follows: the exposure variable was H. pylori infection, and the outcome was incident all-cause and AD dementia. Pooled odds ratios (OR), relative risk (RR), and corresponding 95% confidence intervals (CI) were obtained using the fixed-or random-effect model. Forest plots were generated to summarize the results.
Results: Ten studies involving 96,561 participants were included in the meta-analysis: 5 case-control studies and 5 cohort studies. The overall pooled cohort studies showed a significant positive association between H. pylori infection and all-cause dementia with pooled RR of 1.36 (95% CI, 1.11-1.67). There was no association between H. pylori infection and risk for developing AD: RR of 1.33 (95% CI, 0.86-2.05) in cohort studies, and OR of 1.72 (95% CI, 0.97-3.04) in case-control studies. Significant heterogeneity was showed in each comparison group.
Conclusion: This meta-analysis supports a positive association between H. pylori infection and the risk of all-cause dementia, but not AD dementia. Due to the interference of confounding factors, randomized controlled trials are needed to prove their causality.
Aβ: β-amyloid; AD: Alzheimer’s disease; H. pylori: Helicobacter pylori; RR: relative risk; HR: hazard ratio; OR: odds ratio; CIs: 95% confidence intervals.