title: Periodic extraction of interstitial fluid from the site of subcutaneous insulin infusion for the measurement of glucose: a novel single-port technique for the treatment of type 1 diabetes patients.
abstract: BACKGROUND
  Treatment of type 1 diabetes patients could be simplified if the site of subcutaneous insulin infusion could also be used for the measurement of glucose. This study aimed to assess the agreement between blood glucose concentrations and glucose levels in the interstitial fluid (ISF) that is extracted from the insulin infusion site during periodic short-term interruptions of continuous subcutaneous insulin infusion (CSII).
  
  
  METHODS
  A perforated cannula (24 gauge) was inserted into subcutaneous adipose tissue of C-peptide-negative type 1 diabetes subjects (n=13) and used alternately to infuse rapid-acting insulin (100 U/mL) and to extract ISF glucose during a fasting period and after ingestion of a standard oral glucose load (75 g).
  
  
  RESULTS
  Although periodically interrupted for extracting glucose (every hour for approximately 10 min), insulin infusion with the cannula was adequate to achieve euglycemia during fasting and to restore euglycemia after glucose ingestion. Furthermore, the ISF-derived estimates of plasma glucose levels agreed well with plasma glucose concentrations. Correlation coefficient and median absolute relative difference values were found to be 0.95 and 8.0%, respectively. Error grid analysis showed 99.0% of all ISF glucose values within clinically acceptable Zones A and B (83.5% Zone A, 15.5% Zone B).
  
  
  CONCLUSIONS
  Results show that ISF glucose concentrations measured at the insulin infusion site during periodic short-term interruptions of CSII closely reflect blood glucose levels, thus suggesting that glucose monitoring and insulin delivery may be performed alternately at the same tissue site. A single-port device of this type could be used to simplify and improve glucose management in diabetes.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Graz, Graz, Austria. werner.regittnig@medunigraz.at
authors.forename: Werner
authors.initials: W
authors.lastname: Regittnig
authors.forename: Stefan
authors.initials: S
authors.lastname: Lindpointner
authors.forename: Stefan
authors.initials: S
authors.lastname: Korsatko
authors.forename: Dina
authors.initials: D
authors.lastname: Tutkur
authors.forename: Manfred
authors.initials: M
authors.lastname: Bodenlenz
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Pieber
mesh_terms: D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism*; D003922:Diabetes Mellitus, Type 1 / Q000188:drug therapy / Q000378:metabolism*; D045604:Extracellular Fluid / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D055104:Infusions, Subcutaneous; D007332:Insulin Infusion Systems; D061266:Insulin, Short-Acting / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D061266:Insulin, Short-Acting; D005947:Glucose