title: HbA1c and the diagnosis of diabetes and prediabetes in a middle-aged and elderly Han population from northwest China (HbA1c).
abstract: OBJECTIVE
  To identify the optimal threshold of HbA1c and to evaluate the predictive performance of HbA1c levels in diagnosing diabetes and prediabetes in a middle-aged and elderly Han Chinese population from northwest China.
  
  
  METHODS
  In all, 3354 participants aged ≥ 40 years with no history of diabetes from northwest China were enrolled in the present cross-sectional study. All subjects underwent a 75-g oral glucose tolerance test (OGTT), as well as HbA1c testing. HbA1c thresholds for diagnosing diabetes and prediabetes were identified by the highest sum of sensitivity and specificity of each cut-off point, and the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic accuracy of the HbA1c threshold.
  
  
  RESULTS
  The mean (± SD) age of the participants was 57 ± 8 years, and 70.75% were women. Based on results of the OGTT, 1347 (40.16%) subjects had impaired fasting glucose and/or impaired glucose tolerance, and 725 (21.62%) had diabetes. The area under the ROC curve for detecting undiagnosed diabetes and prediabetes by HbA1c levels was 0.810 (95% confidence interval [CI] 0.796-0.823) and 0.732 (95% CI 0.717-0.747), respectively. HbA1c threshold of 6.4% and 6.1% produced the highest sum of sensitivity (60.00% and 61.49%) and specificity (87.33% and 73.24%) for diagnosing diabetes and prediabetes, respectively.
  
  
  CONCLUSIONS
  HbA1c is an effective and convenient method for diagnosing diabetes and prediabetes. HbA1c thresholds of 6.4% and 6.1% may be used as diagnostic criteria for diabetes and prediabetes, respectively, in the Han Chinese population living in northwest China.
authors: Department of Diabetes, Karamay People's Hospital, Karamay, Xinjiang Uygur Autonomous Region, China. niuyoumou@sohu.com
authors: Shengli
authors: S
authors: Wu
authors: Fengshou
authors: F
authors: Yi
authors: Chao
authors: C
authors: Zhou
authors: Mintao
authors: M
authors: Zhang
authors: Yujing
authors: Y
authors: Zhu
authors: Yilihamu
authors: Y
authors: Tuniyazi
authors: Lijuan
authors: L
authors: Huang
authors: Xuefang
authors: X
authors: Huang
authors: Fugang
authors: F
authors: Wang
authors: Yufang
authors: Y
authors: Bi
authors: Guang
authors: G
authors: Ning
mesh_terms: D000368:Aged; D044466:Asian People; D001786:Blood Glucose / Q000378:metabolism; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology; D005215:Fasting / Q000097:blood; D005260:Female; D005843:Geography; D018149:Glucose Intolerance / Q000097:blood / Q000175:diagnosis / Q000208:ethnology; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000097:blood* / Q000175:diagnosis / Q000208:ethnology; D011237:Predictive Value of Tests; D012372:ROC Curve; D012016:Reference Values
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin
keywords: HbA1c threshold; diabetes; prediabetes; 糖尿病，糖化血红蛋白A1c诊断切点，糖尿病前期