title: Descriptive epidemiology of diabetes prevalence and HbA1c distributions based on a self-reported questionnaire and a health checkup in the JPHC diabetes study.
abstract: BACKGROUND
  The present study examined the prevalence of diabetes in Japan during the late 1990s and early 2000s using the Japan Public Health Center-based Prospective Diabetes cohort. We also investigated the distributions of HbA1c values in noncompliant diabetic participants in the cohort.
  
  
  METHODS
  A total of 28 183 registered inhabitants aged 46-75 years from 10 public health center areas were included in the initial survey. The 5-year follow-up survey included 20 129 participants. The prevalence of diabetes was estimated using both a self-reported questionnaire and laboratory measurements. Among the participants who reported the presence of diabetes on the questionnaire (self-reported diabetes), the distributions of HbA1c values were described according to their treatment status.
  
  
  RESULTS
  The age-standardized prevalence of diabetes in 55- to 74-year-old adults was 8.2% at the initial survey and 10.6% at the 5-year follow-up. At the initial survey, among participants with self-reported diabetes, the mean HbA1c values in the participants who had never and who had previously received diabetes treatment were 7.01% (standard deviation [SD] 1.56%) and 6.56% (SD 1.46%), respectively. Approximately 15% of the participants who had self-reported diabetes but had never received diabetes treatment had an HbA1c ≥ 8.4%.
  
  
  CONCLUSIONS
  The prevalence of diabetes increased in the JPHC cohort between the late 1990s and early 2000s. A certain proportion of participants who were aware of their diabetes but were not currently receiving treatment had poor diabetic control. Efforts to promote continuous medical attendance for diabetes care may be necessary.
authors.affiliation: Department of Diabetes Research, National Center for Global Health and Medicine.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kabeya
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kato
authors.forename: Akihiro
authors.initials: A
authors.lastname: Isogawa
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Yumi
authors.initials: Y
authors.lastname: Matsushita
authors.forename: Atsushi
authors.initials: A
authors.lastname: Goto
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iso
authors.forename: Manami
authors.initials: M
authors.lastname: Inoue
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mizoue
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
authors.forename: Takashi
authors.initials: T
authors.lastname: Kadowaki
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Noda
mesh_terms: D000368:Aged; D003920:Diabetes Mellitus / Q000453:epidemiology* / Q000378:metabolism* / Q000628:therapy; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance / Q000706:statistics & numerical data; D010808:Physical Examination; D015995:Prevalence; D011446:Prospective Studies; D057566:Self Report; D011795:Surveys and Questionnaires
chemical_list: D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human