title: Glucose sensing in the peritoneal space offers faster kinetics than sensing in the subcutaneous space.
abstract: The paramount goal in the treatment of type 1 diabetes is the maintenance of normoglycemia. Continuous glucose monitoring (CGM) technologies enable frequent sensing of glucose to inform exogenous insulin delivery timing and dosages. The most commonly available CGMs are limited by the physiology of the subcutaneous space in which they reside. The very same advantages of this minimally invasive approach are disadvantages with respect to speed. Because subcutaneous blood flow is sensitive to local fluctuations (e.g., temperature, mechanical pressure), subcutaneous sensing can be slow and variable. We propose the use of a more central, physiologically stable body space for CGM: the intraperitoneal space. We compared the temporal response characteristics of simultaneously placed subcutaneous and intraperitoneal sensors during intravenous glucose tolerance tests in eight swine. Using compartmental modeling based on simultaneous intravenous sensing, blood draws, and intraarterial sensing, we found that intraperitoneal kinetics were more than twice as fast as subcutaneous kinetics (mean time constant of 5.6 min for intraperitoneal vs. 12.4 min for subcutaneous). Combined with the known faster kinetics of intraperitoneal insulin delivery over subcutaneous delivery, our findings suggest that artificial pancreas technologies may be optimized by sensing glucose and delivering insulin in the intraperitoneal space.
authors.affiliation: Theranova, LLC, San Francisco, CA.
authors.forename: Daniel R
authors.initials: DR
authors.lastname: Burnett
authors.affiliation: Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA.
authors.forename: Lauren M
authors.initials: LM
authors.lastname: Huyett
authors.affiliation: Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CASansum Diabetes Research Institute, Santa Barbara, CA.
authors.forename: Howard C
authors.initials: HC
authors.lastname: Zisser
authors.affiliation: Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA.
authors.forename: Francis J
authors.initials: FJ
authors.lastname: Doyle
authors.affiliation: Theranova, LLC, San Francisco, CAJanelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, VA menshb@janelia.hhmi.org.
authors.forename: Brett D
authors.initials: BD
authors.lastname: Mensh
mesh_terms: D000818:Animals; D001202:Ascitic Fluid / Q000737:chemistry*; D015374:Biosensing Techniques; D015190:Blood Glucose Self-Monitoring / Q000379:methods*; D003920:Diabetes Mellitus / Q000097:blood / Q000188:drug therapy; D005260:Female; D005947:Glucose / Q000032:analysis*; D005951:Glucose Tolerance Test; D007328:Insulin / Q000008:administration & dosage; D007332:Insulin Infusion Systems; D007700:Kinetics; D019397:Pancreas, Artificial; D010529:Peritoneal Cavity; D040521:Subcutaneous Tissue / Q000737:chemistry*; D013552:Swine
chemical_list: D007328:Insulin; D005947:Glucose