title: Utility of glycosylated haemoglobin in diagnosing diabetes in an
  urban Sri Lankan community
abstract: American Diabetes Association (ADA) has
  officially endorsed glycosylated haemoglobin (HbA1c) as a
  diagnostic tool. The recommended cut-off for diagnosing
  diabetes is  6.5%.
  
  
  
  To compare use of HbA1c and fasting plasma
  glucose (FPG) to diagnose diabetes in an urban Sri Lankan
  community.
  
  
  
  This cross-sectional study is based on baseline
  data from a prospective study on non-communicable
  diseases in randomly selected individuals aged 35-64 years
  in a selected community. HbA1c was measured by National
  Glycohaemoglobin Standardization Program certified Bio
  Rad Variant HbA1c HPLC method. Diagnostic performance
  of HbA1c was evaluated in those without previous diabetes.
  Receiver Operating Characteristic Curve was used to identify
  optimum HbA1c threshold.
  
  
  
  We studied 2516 individuals with no previous history
  of diabetes. Of these 53.8% were women. Mean age was
  52 ± 7.9 years. FPG was 7mmol/l in 245 (9.7%). HbA1c
  was  6.5% in 173 (6.9%). Concordance between FPG and
  HbA1c was 95% (both criteria positive: 5.8%; both criteria
  negative: 89.2%). Compared to FPG, HbA1c cut-off of 6.5%
  had specificity of 98.9% (95% CI 98.3-99.3) and sensitivity
  of 60% (95% CI 53.6-66.2). Positive and negative predictive
  values were 85% (95% CI 78.8-89.9) and 95.8% (95%
  CI 94.9-96.6), respectively. Compared to FPG, optimum
  HbA1c threshold for diagnosing diabetes was 5.9%
  (sensitivity: 84%; specificity: 88.8%; area under the curve:
  0.91).
  
  
  
  In the study population, detection of diabetes
  with ADA recommended HbA1ccriterion was 29% less than
  with FPG criterion. Compared to FPG, HbA1c had high
  specificity but sensitivity was low. Further research is needed
  to refine the optimum HbA1c threshold in Sri Lankans.
authors.affiliation: Faculty of Medicine, University of Kelaniya, Ragama, Sri Lanka. nirmalawijekoon@yahoo.co.uk
authors.forename: C N
authors.initials: CN
authors.lastname: Wijekoon
authors.forename: A
authors.initials: A
authors.lastname: Pathmeswaran
authors.forename: S
authors.initials: S
authors.lastname: Chackrewarthy
authors.forename: N
authors.initials: N
authors.lastname: Kato
authors.forename: A R
authors.initials: AR
authors.lastname: Wickremasinghe