title: Performance of HbA1c for the prediction of diabetes in a rural community in Korea.
abstract: OBJECTIVE
  To investigate the performance of HbA1c in predicting incident diabetes among Korean adults with normal fasting glucose and impaired fasting glucose levels.
  
  
  METHODS
  This study used data from the Korean Genome Epidemiology Study-Kangwha Study. A prospective analysis was carried out on 2079 people (820 men and 1259 women) who completed follow-up examinations up until 2013. Diabetes was defined as fasting blood glucose level ≥ 7.0 mmol/l, HbA1c level ≥ 48 mmol/mol (6.5%), or current treatment for diabetes. Areas under the receiver-operating characteristic curves were used to assess the different performances of HbA1c , glucose and insulin in predicting diabetes.
  
  
  RESULTS
  The median follow-up time was 3.97 years, during which 7.7% of men and 6.3% of women developed incident diabetes. The areas under the receiver-operating curves (95% CI) for diabetes prediction were 0.740 (0.692-0.787) for HbA1c , 0.716 (0.667-0.764) for glucose and 0.598 (0.549-0.648) for insulin. HbA1c showed better predictive power in people with impaired fasting glucose (area under the curve 0.753, 95% CI 0.685-0.821) than in those with normal glucose (area under the curve 0.648, 95% CI 0.577-0.719). An HbA1c threshold of 40 mmol/mol (5.8%) was found to have the highest predictive value for diabetes, with a relative risk of 6.30 (95% CI 3.49-11.35) in men and 3.52 (95% CI 2.06-6.03) in women after adjusting for age, waist circumference, triglycerides, hypertension, family history of diabetes, smoking, alcohol intake, exercise and baseline glucose level.
  
  
  CONCLUSIONS
  HbA1c can be used to identify people at high risk for the development of diabetes, especially in those with impaired fasting glucose levels.
authors.affiliation: Department of Public Health, Ajou University School of Medicine, Suwon, Korea.|Cardiovascular and Metabolic Disease Aetiology Research Centre, Ajou University School of Medicine, Suwon, Korea.
authors.forename: B M
authors.initials: BM
authors.lastname: Song
authors.affiliation: Cardiovascular and Metabolic Disease Aetiology Research Centre, Ajou University School of Medicine, Suwon, Korea.|Department of Preventive Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: H C
authors.initials: HC
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: J Y
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Cardiovascular and Metabolic Disease Aetiology Research Centre, Ajou University School of Medicine, Suwon, Korea.|Department of Preventive Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: J-M
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Cardiovascular and Metabolic Disease Aetiology Research Centre, Ajou University School of Medicine, Suwon, Korea.|Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Korea.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: I
authors.initials: I
authors.lastname: Suh
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000208:ethnology; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis*; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology / Q000208:ethnology; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012306:Risk; D012423:Rural Health / Q000208:ethnology; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; C517652:hemoglobin A1c protein, human