title: HbA(1c) values for defining diabetes and impaired fasting glucose in Asian Indians.
abstract: OBJECTIVE
  To determine the glycosylated haemoglobin (HbA(1c)) cut-points for diabetes and impaired fasting glucose (IFG) among Asian Indians.
  
  
  METHODS
  Participants (n=525) were a random sample selected from the India Health Study. Based on history and fasting plasma glucose (FPG), participants were classified into known diabetes, newly diagnosed diabetes (NDD), impaired fasting glucose (IFG) [ADA and WHO criteria] or normal fasting glucose (NFG). Receiver Operating Characteristic curves were used to identify the optimum sensitivity and specificity for defining HbA(1c) cut-points for NDD and IFG against the FPG criteria.
  
  
  RESULTS
  There were 64 participants with a known history of diabetes. Of the remaining 461, IFG was present in 44.7% (ADA) and 18.2% (WHO), and 10.4% were NDD. Mean HbA(1c) were 5.4 (±0.04)% for NFG; 5.7 (±0.06)% among IFG-ADA, 5.8 (±0.09)% among IFG-WHO; 7.5 (±0.33)% for NDD and 8.4 (±0.32)% for known diabetes. Optimal HbA(1c) cut-point for NDD was 5.8% (sensitivity=75%, specificity=75.5%, AUC=0.819). Cut-point for IFG (ADA) was 5.5% (sensitivity=59.7%, specificity=59.9%, AUC=0.628) and for IFG (WHO) was 5.6% (sensitivity=60.7%, specificity=65.1%, AUC=0.671).
  
  
  CONCLUSIONS
  In this study population from north and south regions of India, the HbA(1c) cut-point that defines NDD (≥5.8%) was much lower than that proposed by an international expert committee and the American Diabetes Association (≥6.5%). A cut-point of ≥5.5% or ≥5.6% defined IFG, and was slightly lower than the ≥5.7% for high risk proposed, but accuracy was less than 70%.
authors.affiliation: Fogarty International Centre & Centre of Excellence-Centre for cArdiometabolic Risk Reduction in South Asia, Public Health Foundation of India, New Delhi 122002, India. dr.manisha.das@gmail.com
authors.forename: Manisha
authors.initials: M
authors.lastname: Nair
authors.forename: Dorairaj
authors.initials: D
authors.lastname: Prabhakaran
authors.forename: K M Venkat
authors.initials: KM
authors.lastname: Narayan
authors.forename: Rashmi
authors.initials: R
authors.lastname: Sinha
authors.forename: Ramakrishnan
authors.initials: R
authors.lastname: Lakshmy
authors.forename: Niveditha
authors.initials: N
authors.lastname: Devasenapathy
authors.forename: Carrie R
authors.initials: CR
authors.lastname: Daniel
authors.forename: Ruby
authors.initials: R
authors.lastname: Gupta
authors.forename: Preethi S
authors.initials: PS
authors.lastname: George
authors.forename: Aleyamma
authors.initials: A
authors.lastname: Mathew
authors.forename: Nikhil
authors.initials: N
authors.lastname: Tandon
authors.forename: K Srinath
authors.initials: KS
authors.lastname: Reddy
mesh_terms: D000704:Analysis of Variance; D044466:Asian People / Q000706:statistics & numerical data*; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis*; D003920:Diabetes Mellitus / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology*; D005215:Fasting / Q000097:blood; D005260:Female; D018149:Glucose Intolerance / Q000097:blood / Q000175:diagnosis* / Q000208:ethnology*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006306:Health Surveys; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015995:Prevalence; D012372:ROC Curve
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human