title: Cutoff value of HbA1c for predicting diabetes and prediabetes in a Chinese high risk population aged over 45.
abstract: OBJECTIVE
  To evaluate the cutoff value of HbA1c for predicting diabetes and prediabetes in a Chinese high risk population aged over 45.
  
  
  METHODS
  A total of 619 people aged over 45 without diabetes were randomly recruited to complete Finnish Diabetes Risk Score (FINDRISC) questionnaire. 208 high-risk individuals (defined by Diabetes Risk Score >=9) had OGTT and HbA1c determined at the same time.
  
  
  RESULTS
  In a Chinese population aged over 45, the best cutoff value of HbA1c for detecting diabetes and prediabetes was 5.8% and 5.4% respectively. The area under the receiver operating characteristic (AUROC) curve of HbA1c for detecting diabetes was 0.85 (95% CI: 0.80-0.90) and prediabetes was 0.62 (95% CI: 0.54-0.70). The combined use of HbA1c and fasting blood glucose (FPG) had larger AUROC than HbA1c alone (0.88, 95%CI: 0.83-0.92 in detecting diabetes vs 0.75, 95% CI: 0.67-0.82 in prediabetes), and had a higher sensitivity in predicting diabetes and higher specificity and positive predictive value (PPV) in predicting prediabetes. However, the AUROC between HbA1c alone and combined use in predicting diabetes was not significantly different (p=0.173).
  
  
  CONCLUSIONS
  FINDRISC is feasible tool to screen people who are at high risk of diabetes. The cutoff values of HbA1c to diagnose diabetes and prediabetes in a Chinese high risk population aged over 45 were 5.8% and 5.4%, respectively. The sensitivity and specificity of HbA1c for detecting diabetes and prediabetes was relatively low, so that the combined use of HbA1c and FPG may be more effective in prediction.
authors.affiliation: Department of Endocrinology, Guangzhou Red Cross Hospital, Medical College of Jinan University, Guangzhou, Guangdong, China.
authors.forename: Ruyi
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Division of Endocrinology, Department of Internal Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Endocrinology, Southern Medical University, Zhujiang Hospital, Guangzhou, Guangdong, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Endocrinology, Southern Medical University, Zhujiang Hospital, Guangzhou, Guangdong, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Endocrinology, Southern Medical University, Zhujiang Hospital, Guangzhou, Guangdong, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Endocrinology, Southern Medical University, Zhujiang Hospital, Guangzhou, Guangdong, China.
authors.forename: Dehong
authors.initials: D
authors.lastname: Cai
authors.affiliation: Department of Endocrinology, Southern Medical University, Zhujiang Hospital, Guangzhou, Guangdong, China. Email: dehongcaizj@163.com.
authors.forename: Hua
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000368:Aged; D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis; D002681:China; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D011236:Prediabetic State / Q000097:blood; D011237:Predictive Value of Tests; D012372:ROC Curve; D018570:Risk Assessment / Q000379:methods; D012680:Sensitivity and Specificity
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin