Utility of glycated hemoglobin in diagnosing type 2 diabetes mellitus: a community-based study

J Clin Endocrinol Metab. 2010 Jun;95(6):2832-5. doi: 10.1210/jc.2009-2433. Epub 2010 Apr 6.


Context: Although glycated hemoglobin (HbA1c) has recently been incorporated as a diagnostic test by the American Diabetes Association, its validity needs to be established in Asian Indians in a community setting.

Objective: The objective of the study was to assess the validity of HbA1c as a screening and diagnostic test in individuals with newly detected diabetes mellitus.

Design and setting: Community based randomized cross sectional study in urban Chandigarh, a city in north India, from April 2008 to August 2009.

Subjects: Subjects included 1972 subjects aged 20 yr or older.

Intervention: Intervention included an oral glucose tolerance test and glycated hemoglobin in all the subjects.

Main outcome measures: Utility of HbA1c as a diagnostic method in newly detected diabetes mellitus subjects was evaluated.

Results: Using World Health Organization criteria for diagnosis of diabetes mellitus, 134 (6.7%) had newly detected diabetes mellitus, 192 (9.7%) known diabetes mellitus, 329 (16.6%) prediabetes, and 1317 (69.4%) were normal of 1972 people screened. Using only the ADA criteria, 38% people were underdiagnosed. An HbA1c level of 6.1% had an optimal sensitivity and specificity of 81% for diagnosing diabetes. A HbA1c level of 6.5% (+/-2 SD) and 7% (+/-2.7 SD) had sensitivity and specificity of 65 and 88% and 42 and 92%, respectively, with corresponding positive predictive value and negative predictive value of 75.2 and 96.5% and 90.4 and 94.4%, respectively, for diagnosis of newly detected diabetes mellitus.

Conclusion: A HbA1c cut point of 6.1% has an optimal sensitivity and specificity of 81% and can be used as a screening test, and a cut point of 6.5% has optimal specificity of 88% for diagnosis of diabetes.

Publication types

  • Randomized Controlled Trial
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Anthropometry
  • Biomarkers
  • Chromatography, High Pressure Liquid
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / diagnosis*
  • Diabetes Mellitus, Type 2 / epidemiology
  • Female
  • Glycated Hemoglobin A / analysis*
  • Humans
  • India / epidemiology
  • Male
  • Middle Aged
  • Prediabetic State / blood
  • Prediabetic State / diagnosis
  • Predictive Value of Tests
  • ROC Curve
  • Reproducibility of Results


  • Biomarkers
  • Glycated Hemoglobin A