Intra-peritoneal Glucose Tolerance Test

An oral glucose tolerance test (OGTT) or intra-peritoneal glucose tolerance test (IPGTT) is used to assess the body’s ability to metabolize glucose.  In humans an OGTT is commonly used to diagnose type 2 diabetes.  In animal research the GTT is used to assess the degree of diabetes and also to test the desired effects of insulin or other drugs on the body’s ability to process glucose.  It can also be used to detect the unintended side-effects of drugs intended to treat other unrelated diseases.

oral glucose tolerance test
Figure 1: Oral glucose tolerance test in two groups of n=3 rats.  The blue line represents the diabetic group and the red line represents the normal group.  The periodic points represent test strip samples.

Figure 2: Intraperitoneal glucose tolerance test in two groups of n=3 rats.  The blue line represents the diabetic group and the red line represents the normal group.  The periodic points represent test strip samples.
Traditional methods of glucose tolerance tests consist of the following basic steps:
  1. Fast the subject for 6-16 hours, depending on the protocol and IACUC considerations.
  2. Weigh the subject.
  3. Calculate the desired glucose dose based on the animal’s weight.
    • Typical oral dose of 2-5 mg/kg or IP dose of 2 mg/kg.
  4. Collect a baseline (predose) blood glucose reading.
  5. Dose the animal
  6. Collect blood glucose data at multiple points along the curve.  For an OGTT this might include points at 5, 15, 30, 60, 120, 180 minutes post-dose.  An IPGTT might include an additional point at 10 minutes and omission of the 180 minute point.

Relevant Parameters from this test include Peak Glucose, Time to Peak, Area Under Curve, Return to Baseline, Glucose at time X

Implantable telemetry will automate this data collection with no need to collect manual measurements other than for (optional) reference purposes.  Continuous data will provide improved resolution in amplitude and time-based parameters.

If doing manual sampling to use as a reference or for calibration purposes, follow guidelines in DSI technical note related to appropriate timing and entry of values into software.

System Components (implantable telemetry applications)
  1. Computer with Ponemah or Dataquest A.R.T. software
    • Automates data collection (continuous or scheduled)
    • Facilitates collection of calibration values
    • Facilitates calibration and reporting of data
  2. MX2 or Data Exchange Matrix and power supply
    • Provides power to receivers
    • Centralizes data collection to computer
  3. Telemetry receivers (typically RPC-1 or RSC-1)
    • Receives telemetry signal and sends to DEM/Computer
  4. HD-XG telemetry devices
    • Records glucose, temperature, and activity for 28 days or longer
  5. Nova StatStrip Xpress handheld glucometer and strips
    • Provides reference glucose values for calibrating implantable devices

Glucose Poster Abstracts

  • Continuous Glucose Monitoring via Telemetry in Rats – ADA 2013

  • Comparison of Continuous Glucose Monitoring Systems in Type 1 Rat Model - ADA 2013

  • Continuous Glucose Monitoring via Telemetry in Rats - EASD 2013

  • Assessment of Insulin Response in STZ Rats Using Continuous Blood Glucose Telemetry – Keystone 2014

  • Continuous glucose and food intake monitoring in the male ZDSD rat: Comparison of normal and high-fat diets - EB 2014

  • Assessment of Insulin Response in STZ Rats Using Continuous Glucose Telemetry - ADA2014

  • Continuous glucose and food intake monitoring in the male ZDSD rat: Comparison of normal and high-fat diets - SSIB 2014

  • Continuous Glucose Correlation with Food Intake in the Male C57BL Mouse - SWCIB 2015

  • 28-day Continuous Glucose Profiles Via Implantable Telemetry in Mice - ENDO 2015

  • Modulation of Blood Glucose Concentration by Vagal Nerve Stimulation - EB 2015

  • Continuous recording of blood glucose reveals that taste modulates the blood glucose response to a gavaged glucose load - SSIB 2015

  • Assessment of the hyperglycemia profile of NVP-BYL719, a selective inhibitor of the class Ia PI3K isoform alpha using real-time continuous glucose monitoring via radio-telemetry in rats - AACR-NCI-EORTC 2015

  • Continuous Glucose Monitoring via Telemetry in Rats - MTS 2015

  • Long-term Continuous Glucose Monitoring in Conscious Stressfree Nonhuman Primates with Implanted Telemetry Device - ADA 2015

  • Fully Implantable Arterial Blood Glucose Device for Metabolic Research Applications in Rats for Two Months - JDST 2015

  • Telemetry for Continuous Glucose Monitoring in Rats - AALAS 2015

  • Impact of a High-Fat Diet on Blood Glucose and Blood Pressure in Female and Male Dahl Salt-Sensitive Rats - APS 2015

  • Continuous Glucose Monitoring for Diabetes, Obesity, and Metabolism Research in Rodents - Webinar 2015

  • Changes in Blood Glucose, Blood Pressure, Heart Rate and Temperature in Rats Challenged with Either Low Carbohydrate, or High Carbohydrate Treats Following a 12 Hour Fast: Changes Tracked Using Dual Telemetry Implants - ENDO 2016

  • Blood Glucose Fluctuations during Daily Activities and Stress Procedures in Cynomolgus Monkeys Monitored By Implanted Telemetry Device - ENDO 2016

  • Unlocking a More Comprehensive Assessment of Diet with Continuous, Chronic Blood Glucose and Complete Hemodynamic Monitoring in Rodents - EB 2016

  • Continuous Glucose Measurements Using Telemetry in Male and Female Dahl Salt-Sensitive Rats on a High-Fat Diet - EB 2016

  • Advantages of Glucose Monitoring with Implantable Telemetry in Freely Moving Conscious Nonhuman Primates - ADA 2016

  • Artificial Intelligence Based Artificial Pancreas System In an Animal Model of Stress Induced Hyperglycemia - ADA 2016

  • Evaluation of a prototype HD-XG telemetry implant for real-time continuous glucose monitoring in mice - FELASA 2016

  • Novel Telemetry Technology for Continuous Glucose Monitoring in Mice - MTS 2016

  • Letter to the Editor: Diabetes in rats is cured by islet transplantation… but only during daytime - CT 2016

  • Continuous Blood Glucose Monitoring in a Rat Model of Islet Transplantation - EASD 2016

  • The Effect of Blood Glucose Telemeter Implantation on Oral Glucose Tolerance Testing and Glucose Monitoring in Diet-Induced Obese Mouse - AALAS 2016

  • Long-term blood glucose monitoring with implanted telemetry device in conscious and stress-free cynomolgus monkeys - JEI 2017

  • Rhythmic Differences of Blood Glucose Circadian Between Normoglycemic and Diabetic Non-Human Primates - ADA 2017

  • Accuracy of Continuous Glucose Telemetry throughout a Stepped Hyperinsulinemic-Euglycemic-Hypoglycemic Clamp in Rats - ADA 2017

  • Continuous Glucose Monitoring in Female NOD Mice Reveals Daily Rhythms and a Negative Correlation With Body Temperature - En 2017

  • Comparison of Continuous Glucose Monitoring between Dexcom G4 Platinum and HD-XG Systems in Nonhuman Primates (Macaca Fascicularis)

  • Decreased complexity of glucose dynamics preceding the onset of diabetes in mice and rats

  • Time-dependent effects of ipragliflozin on behaviour and energy homeostasis in normal and type 2 diabetic rats: continuous glucose telemetry analysis

  • Contrasting effects of afferent and efferent vagal nerve stimulation on insulin secretion and blood glucose regulation

  • Afferent vs. efferent cervical vagal nerve stimulation: effects on blood glucose, insulin, and glucagon concentrations in rats

  • Sustained effect of glucagon on body weight and blood glucose: Assessed by continuous glucose monitoring in diabetic rats

  • Continuous Blood Glucose Monitoring Reveals Enormous Circadian Variations in Pregnant Diabetic Rats

  • From Mouse to Monkey: Revolutionizing Research via Preclinical Continuous Glucose Telemetry

  • Use Of Real-Time Glucose Monitoring In Rats To Investigate Changes In Glucose Excursions And Hypoglycemia After Bariatric Surgery

  • Non-insulin determinant pathways maintain glucose homeostasis upon metabolic surgery

  • High Fat Diet Induced Hypertension is Associated with a Pro-Inflammatory T Cell Profile in Male and Female Dahl Salt Sensitive Rats

  • Improved glucose homeostasis in male obese Zucker rats coincides with enhanced baroreflexes and activation of the nucleus tractus solitarius

  • Glucagon receptor agonists

  • Dosage regimen for a phosphatidylinositol 3-kinase inhibitor

  • Changes in blood glucose as a function of body temperature in laboratory mice: implications for daily torpor

  • Continuous Glucose Monitoring Reduces Stress and Improves Metabolic Data Quality in Mice

Glucose Tolerance Test References

Ayala J., et al, “Standard operating procedures for describing and performing metabolic tests of glucose homeostasis in mice.” Disease Models & Mechanism. Sept/Oct 2010; 3(9-10):525-534. doi:10.1242/dmm.006239

Andrikopoulos S., et al, “Evaluating the glucose tolerance test in mice.” American Journal of Physiology - Endocrinology and Metabolism.  Dec 2008; 295(6):E1323-E1332.  DOI: 10.1152/ajpendo.90617.2008

Kim, J., “Glucose Tolerance Test.” National Mouse Metabolic Phenotyping Centers. Sept 2013.  Available at http://www.mmpc.org/shared/document.aspx?id=141

Haj, F. “Intraperitoneal Glucose Tolerance Test.”  National Mouse Metabolic Phenotyping Centers. Sept 2012.  Available at http://www.mmpc.org/shared/document.aspx?id=85