title: Accuracy of glycated haemoglobin in screening for pre-diabetes in Asian Indians--a community survey: the Chandigarh Urban Diabetes Study (CUDS).
abstract: OBJECTIVE
  To compare American Diabetes Association and International Expert Committee recommended cut-off values of HbA(1c) for detecting the presence of pre-diabetes against plasma glucose values obtained from oral glucose tolerance tests in Asian Indians.
  
  
  METHODS
  A cross-sectional randomly sampled population survey involving 2368 adults, aged ≥ 20 years. HbA(1c) was measured on a Bio-Rad 10 system in 1972 subjects.
  
  
  RESULTS
  Of the 1972 subjects studied, 329 were detected to have pre-diabetes based on isolated impaired fasting glucose in 125 subjects (6.3%), isolated impaired glucose tolerance in 141 subjects (7.1%) and the presence of both in 63 subjects (3.2%). The HbA(1c) cut-off of 34 mmol/mol (5.7%), as recommended by the American Diabetes Association for detecting the presence of pre-diabetes, showed sensitivity of 62%, specificity 77%, with a positive predictive value of 34.7%, a negative predictive value of 89.5% and accuracy of 67.8%; whereas the HbA(1c) cut-off recommended by the International Expert Committee of 42 mmol/mol (6%) had a sensitivity of 36%, specificity of 90%, positive predictive value of 42.7%, negative predictive of 85.4% and an accuracy of 77%. However, both these HbA(1c) cut-offs underdiagnosed the presence of pre-diabetes in 38 and 64% of these subjects, respectively.
  
  
  CONCLUSIONS
  The American Diabetes Association and the International Expert Committee recommended HbA(1c) cut-off values and oral glucose tolerance tests identify different pre-diabetes cohorts. Long-term prospective studies are required to define the usefulness of one over the other.
authors.affiliation: Department of Endocrinology, Postgraduate Institute of Medical Education and Research, Chandigarh, India. anilbhansali_endocrine@rediffmail.com
authors.forename: A
authors.initials: A
authors.lastname: Bhansali
authors.forename: R
authors.initials: R
authors.lastname: Walia
authors.forename: P
authors.initials: P
authors.lastname: Ravi Kumar
authors.forename: M
authors.initials: M
authors.lastname: Ravi Kiran
authors.forename: G
authors.initials: G
authors.lastname: Shanmugasundar
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D003153:Community Health Services; D003430:Cross-Sectional Studies; D005215:Fasting / Q000097:blood*; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008403:Mass Screening; D011236:Prediabetic State / Q000097:blood* / Q000453:epidemiology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D044465:White People / Q000706:statistics & numerical data
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human