title: Time lag of glucose from intravascular to interstitial compartment in humans.
abstract: The accuracy of continuous interstitial fluid (ISF) glucose sensing is an essential component of current and emerging open- and closed-loop systems for type 1 diabetes. An important determinant of sensor accuracy is the physiological time lag of glucose transport from the vascular to the interstitial space. We performed the first direct measurement of this phenomenon to our knowledge in eight healthy subjects under an overnight fasted condition. Microdialysis catheters were inserted into the abdominal subcutaneous space. After intravenous bolus administrations of glucose tracers, timed samples of plasma and ISF were collected sequentially and analyzed for tracer enrichments. After accounting for catheter dead space and assay noise, the mean time lag of tracer appearance in the interstitial space was 5.3-6.2 min. We conclude that in the overnight fasted state in healthy adults, the physiological delay of glucose transport from the vascular to the interstitial space is 5-6 min. Physiological delay between blood glucose and ISF glucose, therefore, should not be an obstacle to sensor accuracy in overnight or fasting-state closed-loop systems of insulin delivery or open-loop therapy assessment for type 1 diabetes.
authors.affiliation: Endocrine Research Unit, Mayo Clinic, Rochester, Minnesota.
authors.forename: Ananda
authors.initials: A
authors.lastname: Basu
authors.forename: Simmi
authors.initials: S
authors.lastname: Dube
authors.forename: Michael
authors.initials: M
authors.lastname: Slama
authors.forename: Isabel
authors.initials: I
authors.lastname: Errazuriz
authors.forename: Jose Carlos
authors.initials: JC
authors.lastname: Amezcua
authors.forename: Yogish C
authors.initials: YC
authors.lastname: Kudva
authors.forename: Thomas
authors.initials: T
authors.lastname: Peyser
authors.forename: Rickey E
authors.initials: RE
authors.lastname: Carter
authors.forename: Claudio
authors.initials: C
authors.lastname: Cobelli
authors.forename: Rita
authors.initials: R
authors.lastname: Basu
mesh_terms: D000328:Adult; D001692:Biological Transport; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D017551:Microdialysis; D008875:Middle Aged
chemical_list: D001786:Blood Glucose; D005947:Glucose