title: Effect of baseline HbA1c level on the development of diabetes by lifestyle intervention in primary healthcare settings: insights from subanalysis of the Japan Diabetes Prevention Program.
abstract: OBJECTIVE
  To determine the effects of a lifestyle intervention on the development of type 2 diabetes mellitus (T2DM) among participants with impaired glucose tolerance (IGT), in particular in the subgroup with baseline glycated hemoglobin (HbA1c) levels ≥5.7%, in primary healthcare settings.
  
  
  METHODS
  Randomized controlled trial.
  
  
  METHODS
  32 healthcare centers in Japan.
  
  
  METHODS
  Participants with IGT, aged 30-60 years, were randomly assigned to either an intensive lifestyle intervention group (ILG) or a usual care group (UCG).
  
  
  METHODS
  During the initial 6 months, participants in the ILG received four group sessions on healthy lifestyles by public health providers. An individual session was further conducted biannually during the 3 years. Participants in the UCG received usual care such as one group session on healthy lifestyles.
  
  
  METHODS
  The primary endpoint was the development of T2DM based on an oral glucose tolerance test.
  
  
  RESULTS
  The mean follow-up period was 2.3 years. The annual incidence of T2DM were 2.7 and 5.1/100 person-years of follow-up in the ILG (n=145) and UCG (n=149), respectively. The cumulative incidence of T2DM was significantly lower in the ILG than in the UCG among participants with HbA1c levels ≥5.7% (log-rank=3.52, p=0.06; Breslow=4.05, p=0.04; Tarone-Ware=3.79, p=0.05), while this was not found among participants with HbA1c levels <5.7%.
  
  
  CONCLUSIONS
  Intensive lifestyle intervention in primary healthcare setting is effective in preventing the development of T2DM in IGT participants with HbA1c levels ≥5.7%, relative to those with HbA1c levels <5.7%.
  
  
  BACKGROUND
  UMIN000003136.
authors.affiliation: Division of Preventive Medicine , Clinical Research Institute , National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Sakane
authors.affiliation: Department of General Medicine/Family & Community Medicine , Nagoya University Graduate School of Medicine , Nagoya , Japan.
authors.forename: Juichi
authors.initials: J
authors.lastname: Sato
authors.affiliation: Comprehensive Health Science Center, Aichi Health Promotion Foundation, Higashiura-cho , Aichi , Japan.
authors.forename: Kazuyo
authors.initials: K
authors.lastname: Tsushita
authors.affiliation: Diabetes Center, Tenri Yorozu-sodansho Hospital , Tenri , Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Tsujii
authors.affiliation: Division of Preventive Medicine , Clinical Research Institute , National Hospital Organization Kyoto Medical Center , Kyoto , Japan ; Department of Clinical Laboratory Medicine , Jichi Medical School , Tochigi , Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kotani
authors.affiliation: Division of Internal Medicine , Hananoki Hospital , Tochigi , Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Tominaga
authors.affiliation: Department of Diabetes and Metabolism , Marunouchi Hospital, The Institute for Adult Diseases, Asahi Life Foundation , Tokyo , Japan.
authors.forename: Shoji
authors.initials: S
authors.lastname: Kawazu
authors.affiliation: The Graduate Center of Human Sciences, Aichi Mizuho College, Nagoya , Japan.
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Division of Endocrinology , Clinical Research Institute, National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Usui
authors.affiliation: Graduate School of Public Policy, The University of Tokyo , Tokyo , Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Kamae
authors.affiliation: Obesity and Diabetes Center, Shimabara Hospital , Kyoto , Japan.
authors.forename: Toshihide
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Department of Medicine and Clinical Science , Graduate School of Medical Sciences, Kyusyu University , Fukuoka , Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kiyohara
authors.affiliation: Hirakata General Hospital for Developmental Disorders , Hirakata, Osaka , Japan.
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Sato
authors.affiliation: Division of Preventive Medicine , Clinical Research Institute , National Hospital Organization Kyoto Medical Center , Kyoto , Japan.
authors.forename: Kokoro
authors.initials: K
authors.lastname: Tsuzaki
authors.affiliation: Division of Preventive Medicine , Clinical Research Institute , National Hospital Organization Kyoto Medical Center , Kyoto , Japan ; Hyogo Health Service Association , Hyogo , Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: National Hospital Organization Kyoto Medical Center , Kyoto , Japan ; Takeda Hospital , Kyoto , Japan.
authors.forename: Hideshi
authors.initials: H
authors.lastname: Kuzuya
keywords: HbA1c; Impaired Glucose Tolerance; Intervention Groups; Type 2 Diabetes