title: The relationship between glycosylated haemoglobin (HbA1c) and measures of insulin resistance across a range of glucose tolerance.
abstract: OBJECTIVE
  This study aimed to assess the correlation between HbA1c and insulin resistance as measured by a variety of different indices in subjects from across the glycaemic spectrum.
  
  
  METHODS
  Subjects with normal glucose tolerance (NGT; n = 24), impaired fasting glucose (IFG; n = 12), impaired glucose tolerance (IGT; n = 12), and type 2 diabetes (DM; n = 13) were studied. All had specimens taken in the context of a standard oral glucose tolerance test at their first visit and had the insulin sensitivity parameter (Si) determined by frequently-sampled intravenous glucose tolerance test at a second visit.
  
  
  RESULTS
  HbA1c was more strongly associated with Si in NGT (r = - 0.65) than in IFG (r = - 0.48). Compared to other indices of insulin resistance HbA1c has minimal overlap in values (0.0%) between NGT and subjects with type 2 diabetes.
  
  
  CONCLUSIONS
  HbA1c can be used as a simple and reliable marker of insulin resistance in NGT adults with relatively high insulin sensitivity.
authors.affiliation: Department of Pathology, King Khalid National Guard Hospital, Jeddah, Saudi Arabia. boraiaa@ngha.med.sa
authors.forename: Anwar
authors.initials: A
authors.lastname: Borai
authors.forename: Callum
authors.initials: C
authors.lastname: Livingstone
authors.forename: Fatima
authors.initials: F
authors.lastname: Abdelaal
authors.forename: Ali
authors.initials: A
authors.lastname: Bawazeer
authors.forename: Vuyolethu
authors.initials: V
authors.lastname: Keti
authors.forename: Gordon
authors.initials: G
authors.lastname: Ferns
mesh_terms: D000328:Adult; D000368:Aged; D005215:Fasting / Q000097:blood; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D006442:Glycated Hemoglobin