title: Dietary carbohydrate intake, presence of obesity and the incident risk of type 2 diabetes in Japanese men.
abstract: OBJECTIVE
  The present cohort study assessed the risk among Japanese men for developing type 2 diabetes, based on the percentage of energy intake from carbohydrates and degree of obesity.
  
  
  METHODS
  The participants were 2,006 male factory employees, and the macronutrient intake of each patient was measured using a self-administered diet history questionnaire. The incidence of diabetes was determined in annual blood examinations over a 10-year period.
  
  
  RESULTS
  During the study, 232 participants developed diabetes. The crude incidence rates (/1,000 person-years) for different levels of carbohydrate intake as a percentage of calories consumed (<50.0, 50.0-57.4, 57.5-65.0, >65.0% of energy intake) were 16.5, 14.4, 12.7 and 17.6. Overall, carbohydrate intake was not associated with the risk of diabetes. However, there was significant interaction between carbohydrate intake and degree of obesity on the incidence of diabetes (P for interaction = 0.024). Higher carbohydrate intake was associated with elevated risk for diabetes among participants with a body mass index ≥25.0 kg/m(2) (P for trend = 0.034). For obese participants, the multivariate-adjusted hazard ratio for those with carbohydrate intakes >65% energy was 2.01 (95% confidence interval 1.08-3.71), which was significantly higher than that of participants with carbohydrate intakes 50.0-57.4% energy.
  
  
  CONCLUSIONS
  Higher carbohydrate intake was associated with higher risk of diabetes in obese participants, but not in non-obese participants. Obese participants with carbohydrate intakes >65% energy should reduce their intakes to levels within the desirable carbohydrate energy proportion for Japanese (50-65% energy) to prevent development of type 2 diabetes.
authors.affiliation: Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Sakurai
authors.affiliation: Department of Public Health Hokkaido University Graduate School of Medicine Sapporo Japan.
authors.forename: Koshi
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Department of Health Science Shiga University of Medical Science Otsu Japan.
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Miura
authors.affiliation: Department of Disease Control and Homeostasis Kanazawa University Graduate School of Medical Science Kanazawa Japan.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Takamura
authors.affiliation: Department of Food Science and Nutrition Graduate School of Human Life Science Osaka City University Osaka Japan.
authors.forename: Katsushi
authors.initials: K
authors.lastname: Yoshita
authors.affiliation: Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan.
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Nagasawa
authors.affiliation: Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Morikawa
authors.affiliation: Department of Social and Environmental Medicine Kanazawa Medical University Ishikawa Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Ishizaki
authors.affiliation: School of Health Sciences College of Medical Pharmaceutical and Health Sciences Kanazawa University Kanazawa Japan.
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Kido
authors.affiliation: Department of Human Science and Fundamental Nursing Toyama University Toyama Japan.
authors.forename: Yuchi
authors.initials: Y
authors.lastname: Naruse
authors.affiliation: Department of Community Health Nursing Kanazawa Medical University Ishikawa Japan.
authors.forename: Motoko
authors.initials: M
authors.lastname: Nakashima
authors.affiliation: Department of Occupation and Environmental Medicine Graduate School of Medicine Chiba University Chiba Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nogawa
authors.affiliation: Department of Occupation and Environmental Medicine Graduate School of Medicine Chiba University Chiba Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Suwazono
authors.affiliation: Department of Social and Preventive Epidemiology School of Public Health The University of Tokyo Tokyo Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.affiliation: Department of Epidemiology and Public Health Kanazawa Medical University Ishikawa Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nakagawa
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000453:epidemiology*; D004040:Dietary Carbohydrates; D002149:Energy Intake; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000453:epidemiology*; D012307:Risk Factors
chemical_list: D004040:Dietary Carbohydrates
keywords: Cohort study; Dietary carbohydrates; Incidence