title: Insulin administration and rate of glucose appearance in people with type 1 diabetes.
abstract: OBJECTIVE
  To assess whether prandial insulin, in addition to basal insulin, has an effect on the rate of glucose appearance from a meal in people with type 1 diabetes.
  
  
  METHODS
  The rate of glucose appearance from a mixed meal (Ra(meal)) was investigated in six adult (aged 24 +/- 2 years), lean (BMI 23.6 +/- 1.5 kg/m(2)) subjects with well-controlled type 1 diabetes (duration 7.9 +/- 6.9 years, A1C 7.6 +/- 0.9%) with/without prandial insulin. Actrapid was infused to maintain euglycemia before meals were consumed. Subjects consumed two identical meals on separate occasions, and Ra(meal) was measured using a dual isotope method. [6,6-(2)H(2)]glucose was incorporated into the meal (0.081 g/kg body wt), and a primed constant/variable rate infusion of [1,2,3,4,5,6,6-(2)H(2)]glucose was administered. In the tests with prandial insulin, an additional bolus dose of Actrapid was given 20 min before the meal at 0.1 units/kg body wt.
  
  
  RESULTS
  Insulin concentration with prandial insulin was significantly higher than during basal insulin studies (119 +/- 16 vs. 66 +/- 15 pmol/l, P = 0.03 by paired t test). Despite differences in insulin concentration, there were no differences in total glucose appearance (3,398 +/- 197 vs. 3,307 +/- 343 micromol/kg) or time taken for 25% (33.1 +/- 3.3 vs. 31.7 +/- 3.5 min), 50% (54.6 +/- 3.5 vs. 54.1 +/- 4.7 min), and 75% (82.9 +/- 7.1 vs. 82.8 +/- 5.8 min) of total glucose appearance. The fraction of the glucose dose appearing in the circulation was the same for basal (73 +/- 8%) and prandial (75 +/- 4%) study days.
  
  
  CONCLUSIONS
  These results suggest that meal glucose appearance is independent of prandial insulin concentration in people with type 1 diabetes.
authors.affiliation: Medical Research Council, Human Nutrition Research, Cambridge, UK. m.pennant@bham.ac.uk
authors.forename: Mary E
authors.initials: ME
authors.lastname: Pennant
authors.forename: Leslie J C
authors.initials: LJ
authors.lastname: Bluck
authors.forename: M Loredana
authors.initials: ML
authors.lastname: Marcovecchio
authors.forename: Burak
authors.initials: B
authors.lastname: Salgin
authors.forename: Roman
authors.initials: R
authors.lastname: Hovorka
authors.forename: David B
authors.initials: DB
authors.lastname: Dunger
mesh_terms: D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy* / Q000378:metabolism; D004334:Drug Administration Schedule; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D007328:Insulin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use*; D049528:Insulin, Long-Acting; D008297:Male; D055815:Young Adult
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin; D049528:Insulin, Long-Acting; D005947:Glucose