title: Are the glycemic and insulinemic index values of carbohydrate foods similar in healthy control, hyperinsulinemic and type 2 diabetic patients?
abstract: OBJECTIVE
  a criticism of glycemic index (GI) is that it does not indicate the insulin response of foods (insulinemic index, II). However, it is unknown if the GI and II values of foods are equivalent in all subjects, a necessary criterion for clinical utility. We compared GI and II values in non-diabetic subjects with fasting-serum-insulin (FSI) <40 pmol/l (healthy control) or with FSI ≥ 40 pmol/l (hyper[I]) and subjects with type 2 diabetes (T2DM), and to see whether GI and II were related to the serum-glucose concentrations, insulin sensitivity, β-cell function and hepatic insulin extraction (HIE) of the subjects.
  
  
  METHODS
  Serum-glucose, -insulin and -C-peptide responses after 50 g available-carbohydrate portions of glucose (tested three times by each subject), sucrose, instant mashed-potato, white-bread, polished-rice and pearled-barley were measured in healthy control (n=9), hyper[I] (n=12) and T2DM (n=10) subjects.
  
  
  RESULTS
  Food GI values did not differ significantly among the three subject groups, whereas II values were higher in T2DM (100±7) than healthy controls (78±5) and hyper[I] subjects (70±5) (mean±s.e.m., P=0.05). II was inversely associated with insulin sensitivity (r=-0.66, P<0.0001) and positively related to fasting- and postprandial-glucose (both r=0.68, P<0.0001) and HIE (r=0.62, P=0.0002). In contrast, GI was not related to any of the biomarkers (P>0.05).
  
  
  CONCLUSIONS
  The GI is a valid property of foods because its value is similar in healthy control, hyper [I] and T2DM subjects, and is independent of subjects' metabolic status. However, II may depend upon the glycaemic control, insulin sensitivity and HIE of the subjects.
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Ontario, Canada.
authors.forename: X
authors.initials: X
authors.lastname: Lan-Pidhainy
authors.forename: T M S
authors.initials: TM
authors.lastname: Wolever
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D004040:Dietary Carbohydrates / Q000097:blood*; D005260:Female; D038321:Glycemic Index; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood*; D007328:Insulin / Q000097:blood*; D007333:Insulin Resistance; D008875:Middle Aged; D019518:Postprandial Period; D012016:Reference Values; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D007328:Insulin