Does Helicobacter pylori Infection Increase Incidence of Dementia? The Personnes Agees QUID Study

Objectives To determine whether Helicobacter pylori infection was associated with dementia and risk of developing dementia in a longitudinal population-based cohort of elderly adults living in the community. Design Prospective community-based cohort study. Setting The population-based Personnes Agees QUID (PAQUID) Study. Participants Six hundred three noninstitutionalized individuals aged 65 and older living in the southwest of France followed from 1989 to 2008. Measurements A descriptive and comparative analysis including dementia prevalence, according to H. pylori status (serology), was made at baseline. Cox proportional hazard models were used to study the risk of developing dementia according to H. pylori status assessed on sera samples from elderly adults initially free of dementia and followed for 20 years. A neurologist diagnosed dementia according to Diagnostic and Statistical Manual of Mental Disorders Third Edition criteria. Results At baseline, 391 (64.8%) subjects (348 women, mean age 73.9 +/- 6.5) were seropositive for H. pylori. Dementia prevalence was higher in the infected group (5.4% vs 1.4%, P = .02). After 20 years of follow-up, 148 incident cases of dementia were diagnosed. After controlling for age, sex, educational level, apolipoprotein E4 status, cardiovascular risk factors, and Mini-Mental State Examination score, H. pylori infection was determined to be a risk factor for developing dementia (hazard ratio = 1.46, P = .04). Conclusion This longitudinal population-based study provides additional epidemiological support to the hypothesis of an association between dementia and H. pylori infection, which may enhance neurodegeneration.