Helicobacter pylori seropositivity and its association with incident all‐cause and Alzheimer's disease dementia in large national surveys

Introduction Infectious agents were recently implicated in Alzheimer's disease (AD) and etiology of other dementias, notably Helicobacter pylori . Methods We tested associations of H. pylori seropositivity with incident all‐cause and AD dementia and with AD‐related mortality among US adults in a retrospective cohort study. Data from the National Health and Nutrition Surveys III, phase 1 (1988–1991) and 1999–2000 linked with Medicare and National Death Index registries, were used (baseline age ≥45 y, follow‐up to 2013, N pooled = 5927). Results A positive association between H. pylori seropositivity and AD mortality was found in men (hazard ratio adj, pooled = 4.33, 95% confidence interval: 1.51–12.41, P = .006), which was replicated for incident AD and all‐cause dementia, with hazard ratio adj, pooled = 1.45 (95% confidence interval: 1.03–2.04, P = .035) and hazard ratio adj, III = 1.44 (95% confidence interval: 1.05–1.98, P = .022), respectively. These associations were also positive among higher socioeconomic status groups. Discussion In sum, H. pylori seropositivity's direct association with AD mortality, all‐cause dementia, and AD dementia was restricted to men and to higher socioeconomic status groups.