title: Interaction between exogenous insulin, endogenous insulin, and glucose in type 2 diabetes patients.
abstract: BACKGROUND
  Little is known about the influence of exogenous insulin and actual glucose levels on the release of endogenous insulin in insulin-treated type 2 diabetes mellitus (T2DM) patients. This study investigated the interaction among serum endogenous insulin (s-EI), serum exogenous insulin aspart (s-IAsp), and blood glucose levels in an experimental short-term crossover design.
  
  
  METHODS
  Eight T2DM patients (63.52 years old; range, 49-69 years; mean body mass index, 28.8±3.8 kg/m(2)) were randomized to treatment with individual fixed doses of insulin aspart (0.5-1.5 IU/h) as a continuous subcutaneous insulin infusion (CSII) during a 10-h period on two occasions with different duration of hyperglycemia: (1) transient hyperglycemia for 2 h (visit TH) and (2) continuous hyperglycemia for 12 h (visit CH).
  
  
  RESULTS
  During steady state the variances of plasma glucose (p-glucose), s-IAsp, and s-EI were equal within visit TH and within visit CH, but variances were significantly higher during visit CH compared with visit TH. The s-IAsp reached lower levels at visit CH compared with visit TH (test for slope=1, P=0.005). The s-EI depended on p-glucose in a nonlinear fashion during the first 100 min of both visits when s-IAsp was undetectable (adjusted R(2)=0.9). A complex but statistically significant interaction among s-IAsp, s-EI, p-glucose, and patients was observed during measurable s-IAsp levels (adjusted R(2)=0.70).
  
  
  CONCLUSIONS
  Endogenous and exogenous insulin showed higher variation during continuous hyperglycemia. Significantly lower levels of exogenous insulin were observed following CSII during continuous hyperglycemia compared with transient hyperglycemia. Endogenous insulin levels could in a complex way be explained by an individual interaction among p-glucose and serum exogenous insulin, if present.
authors.affiliation: 1 Department of Endocrinology and Internal Diseases, Aarhus University Hospital , Aarhus, Denmark .
authors.forename: Jurgita
authors.initials: J
authors.lastname: Janukonyté
authors.forename: Tina
authors.initials: T
authors.lastname: Parkner
authors.forename: Niels Henrik
authors.initials: NH
authors.lastname: Bruun
authors.forename: Torsten
authors.initials: T
authors.lastname: Lauritzen
authors.forename: Jens Sandahl
authors.initials: JS
authors.lastname: Christiansen
authors.forename: Torben
authors.initials: T
authors.lastname: Laursen
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000187:drug effects*; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000097:blood* / Q000188:drug therapy; D007004:Hypoglycemic Agents / Q000097:blood* / Q000627:therapeutic use; D055104:Infusions, Subcutaneous; D007328:Insulin / Q000097:blood*; D061267:Insulin Aspart / Q000008:administration & dosage / Q000097:blood*; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D008875:Middle Aged
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin; D008687:Metformin; D061267:Insulin Aspart