title: Psychosocial factors are independent risk factors for the development of Type 2 diabetes in Japanese workers with impaired fasting glucose and/or impaired glucose tolerance.
abstract: OBJECTIVE
  We prospectively studied Japanese workers with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and analysed possible risk factors for diabetes, including psychosocial factors such as stress.
  
  
  METHODS
  The participants were 128 male Japanese company employees (mean age, 49.3 +/- 5.9 years) with IFG and/or IGT diagnosed by oral glucose tolerance test (OGTT). Participants were prospectively studied for 5 years with annual OGTTs. The Kaplan-Meier method and Cox's proportional hazard model were used to analyse the incidence of diabetes and the factors affecting glucose tolerance, including anthropometric, biochemical and social-psychological factors.
  
  
  RESULTS
  Of 128 participants, 36 (28.1%) developed diabetes and 39 (30.5%) returned to normal glucose tolerance (NGT) during a mean follow-up of 3.2 years. Independent risk factors for diabetes were night duty [hazard ratio (HR) = 5.48, P = 0.002], higher fasting plasma glucose (FPG) levels within 6.1-6.9 mmol/l (HR = 1.05, P = 0.031), stress (HR = 3.81, P = 0.037) and administrative position (HR = 12.70, P = 0.045), while independent factors associated with recovery were lower FPG levels (HR = 0.94, P = 0.017), being a white-collar worker (HR = 0.34, P = 0.033), non-smoking (HR = 0.31, P = 0.040) and lower serum alanine aminotransferase (ALT) levels (HR = 0.97, P = 0.042).
  
  
  CONCLUSIONS
  In addition to FPG levels at baseline, psychosocial factors (night duty, stress and administrative position) are risk factors for Type 2 diabetes, while being a white-collar worker, a non-smoker and lower serum ALT levels are factors associated with return to NGT in Japanese workers with IFG and/or IGT.
authors.affiliation: Department of Diabetes and Metabolism, Iwate Medical University, Morioka, Iwate, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Toshihiro
authors.forename: K
authors.initials: K
authors.lastname: Saito
authors.forename: S
authors.initials: S
authors.lastname: Takikawa
authors.forename: N
authors.initials: N
authors.lastname: Takebe
authors.forename: T
authors.initials: T
authors.lastname: Onoda
authors.forename: J
authors.initials: J
authors.lastname: Satoh
mesh_terms: D000328:Adult; D016009:Chi-Square Distribution; D003924:Diabetes Mellitus, Type 2 / Q000523:psychology*; D018450:Disease Progression; D018149:Glucose Intolerance / Q000523:psychology*; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011236:Prediabetic State / Q000523:psychology*; D011446:Prospective Studies; D011584:Psychology; D012307:Risk Factors; D012907:Smoking; D013315:Stress, Psychological