title: Association between Helicobacter pylori infection and dementia.
abstract: Dementia is the severe loss of global cognitive ability in a previously healthy person. This study examined the relationship between Helicobacter pylori infection (HP-I) and non-Alzheimer's dementia (non-AD) using a nationwide population-based dataset. The International Classification of Diseases, Ninth Revision (ICD-9) codes for dementia were used to define dementia patients; in addition, we examined the association of dementia with other comorbidities. Patients aged ≥40years with newly diagnosed HP-I (ICD-9 code 041.86) during 1998-2010 were identified as the HP-I cohort. The comparison cohort consisted of people aged ≥40years without HP-I (non-HP-I) randomly selected from the database at a ratio of 1:4 in the same time period. The controls were frequency matched according to the age (every 5years), sex, and index year of patients in the HP-I cohort. Follow-up was performed for all patients until the date of dementia diagnosis (ICD-9 codes 290.0-290.4, 294.1, 331.0-331.2), date of withdrawal from the Taiwanese National Health Insurance program, date of death, or until December 31 2010. Compared with patients without HP-I, HP-I patients were 1.60-fold (95% confidence interval [CI] 1.32-1.95) more likely to develop non-AD. There was no statistical association between HP-I and AD. The adjusted hazard ratio of dementia increased from 1.48 (95% CI 1.22-1.79) for patients who had HP-I once to 2.19 (95% CI 1.13-4.25) for patients who had HP-I two or more times. Our study revealed that HP-I may be a critical risk factor for the development of non-AD. Further investigation, including clinical trials, to examine the microbe-dementia connection may provide further proof of the association between HP-I and dementia.
authors.affiliation: Department of Neurology, China Medical University Hospital, Taichung, Taiwan; Graduate Institute of Clinical Medicine Science and School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Wei-Shih
authors.initials: WS
authors.lastname: Huang
authors.affiliation: Molecular and Genomic Epidemiology Center, China Medical University Hospital, China Medical University, Taichung, Taiwan.
authors.forename: Tse-Yen
authors.initials: TY
authors.lastname: Yang
authors.affiliation: Department of Computer Science and Information Engineering, Asia University, Taichung, Taiwan.
authors.forename: Wei-Chih
authors.initials: WC
authors.lastname: Shen
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Cheng-Li
authors.initials: CL
authors.lastname: Lin
authors.affiliation: Department of Nuclear Medicine, E-DA Hospital, Kaohsiung, Taiwan.
authors.forename: Ming-Chia
authors.initials: MC
authors.lastname: Lin
authors.affiliation: Graduate Institute of Clinical Medicine Science and School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan. Electronic address: d10040@mail.cmuh.org.tw.
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Kao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003704:Dementia / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori; D006801:Humans; D015994:Incidence; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology
keywords: Cohort study; Dementia; Helicobacter pylori