Study on Helicobacter pylori Infection and Alzheimer's Disease Risk

A comprehensive population-based study conducted over nearly three decades has shed light on a potential link between clinically apparent Helicobacter pylori infection (CAHPI) and the risk of developing Alzheimer's disease (AD). This study was published in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association journal. The study, utilizing the United Kingdom's Clinical Practice Research Datalink (UK CPRD), aimed to investigate whether there exists an association between CAHPI and the onset of AD in individuals aged 50 years and above.

The study involved a vast cohort of over 4 million dementia-free subjects. Through a nested case-control approach, researchers matched each newly diagnosed case of AD with 40 controls. The analysis used conditional logistic regression to estimate the odds ratios (ORs) and their 95% confidence intervals (CIs) for AD risk associated with CAHPI compared to no CAHPI, specifically considering a time frame of two or more years preceding the index date. Additionally, salmonellosis served as a negative control exposure for comparative purposes.

The findings unveiled a noteworthy association between CAHPI and an increased risk of AD, with the OR for AD risk being 1.11 (95% CI, 1.01–1.21) when compared to individuals without CAHPI. Intriguingly, salmonellosis did not exhibit any significant association with the risk of AD, as indicated by an OR of 1.03 (95% CI, 0.82–1.29).

Key Highlights from the Study

• CAHPI was linked to an 11% heightened risk of developing AD among individuals aged 50 years and above.
• The risk of AD peaked at 24% approximately a decade after the onset of CAHPI.
• The study noted no substantial effect modification by age or sex, suggesting a consistent association across demographic groups.
• Rigorous sensitivity analyses aimed at addressing potential biases consistently supported the association between CAHPI and AD risk.

This comprehensive investigation provides compelling evidence suggesting a moderate association between clinically apparent Helicobacter pylori infection and the risk of developing Alzheimer's disease. However, the study authors caution that further research is needed to establish a causal relationship and unravel the underlying mechanisms driving this association.

Reference

Douros, A., Ante, Z., Fallone, C. A., Azoulay, L., Renoux, C., Suissa, S., & Brassard, P. Clinically apparent Helicobacter pylori infection and the risk of incident Alzheimer’s disease: A population‐based nested case‐control study. Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, 2023. https://doi.org/10.1002/alz.13561