title: Hyperglycemia increases risk of gastric cancer posed by Helicobacter pylori infection: a population-based cohort study.
abstract: OBJECTIVE
  Although diabetes mellitus and hyperglycemia are considered to be possible risk factors for various types of malignancy, the epidemiologic evidence concerning gastric cancer is scarce. The aim of this study was to evaluate the impact of hemoglobin A1c (HbA1c) levels on gastric cancer occurrence and their interaction with Helicobacter pylori infection.
  
  
  METHODS
  A total of 2603 Japanese subjects aged>or=40 years were stratified into 4 groups according to baseline HbA1c levels (<or=4.9%, 5.0%-5.9%, 6.0%-6.9%, and >or=7.0%) and followed up prospectively for 14 years.
  
  
  RESULTS
  During the follow-up, 97 subjects developed gastric cancer. The age- and sex-adjusted incidence of gastric cancer significantly increased in the 6.0%-6.9% (5.1 per 1000 person-years; P<.05) and >or=7.0% groups (5.5 per 1000 person-years; P<.05) compared with the 5.0%-5.9% group (2.5 per 1000 person-years), whereas it was slightly but not significantly high in the <or=4.9% group (3.6 per 1000 person-years). This association remained substantially unchanged even after adjusting for the confounding factors including Helicobacter pylori seropositivity, (multivariate-adjusted hazard ratio [HR], 2.13; 95% confidence interval [CI]: 1.30-3.47 for the 6.0%-6.9% group and HR, 2.69; 95% CI: 1.24-5.85 for the >or=7.0% group). Among subjects who had both high HbA1c levels (>or=6.0%) and Helicobacter pylori infection, the risk of gastric cancer was dramatically elevated (interaction term, P=.004).
  
  
  CONCLUSIONS
  Our findings suggest that casual hyperglycemia is a risk factor for gastric cancer and is a possible cofactor increasing the risk posed by Helicobacter pylori infection.
authors.affiliation: Department of Environmental Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. fumikeda@envmed.med.kyushu-u.ac.jp
authors.forename: Fumie
authors.initials: F
authors.lastname: Ikeda
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Doi
authors.forename: Koji
authors.initials: K
authors.lastname: Yonemoto
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Ninomiya
authors.forename: Michiaki
authors.initials: M
authors.lastname: Kubo
authors.forename: Kentaro
authors.initials: K
authors.lastname: Shikata
authors.forename: Jun
authors.initials: J
authors.lastname: Hata
authors.forename: Yumihiro
authors.initials: Y
authors.lastname: Tanizaki
authors.forename: Takayuki
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Iida
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kiyohara
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000150:complications*; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000382:microbiology*
chemical_list: D006442:Glycated Hemoglobin