NCT01474889

Glucose Counterregulation in Long Standing Type 1 Diabetes

Effect of Real-Time Continuous Glucose Monitoring on Glucose Counterregulation in Long Standing Type 1 Diabetes

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 37 (actual)
• Sponsor: University of Pennsylvania · Academic / Other
• Sex: All
• Age: 25 Years – 70 Years
• Healthy volunteers: Not accepted

Summary

Enrollment for this study is complete. This study is designed to determine if use of a real-time continuous glucose monitor (RT-CGM) can reverse defective Glucose counter regulation and hypoglycemia unawareness in long standing type 1 diabetes.

Detailed description

The present protocol is designed to determine whether strict hypoglycemia avoidance by real-time continuous glucose monitoring (RT-CGM), can restore endogenous glucose production in response to hypoglycemia in patients with long standing disease. Twelve subjects with long standing type 1 diabetes complicated by hypoglycemia unawareness underwent assessment of the endogenous glucose production response to insulin-induced hypoglycemia using paired hyperinsulinemic euglycemic and hypoglycemic clamps with stable glucose isotope infusions before and at 6 and 18 months following initiation of RT-CGM. The primary analysis will be change in the endogenous glucose production response from before to 6 months following initiation of RT-CGM, and a secondary analysis will consider the persistence of any change at 18 months. The clinical significance of any determined changes in the endogenous glucose production response to insulin-induced hypoglycemia will be determined by comparison to responses obtained using paired hyperinsulinemic euglycemic and hypoglycemic clamps on one occasion in a matched control group of 12 subjects with long-standing type 1 diabetes but no hypoglycemia unawareness (GROUP 2) and in a matched control group of 12 nondiabetic subjects (GROUP 3). Arms are not assigned to these two control groups in ct.gov as they were only used as a baseline for clinical significance. Neither group wore a CGM nor are they analyzed at 6-month and 18-month time-points. This said, for control group clarification, inclusion and exclusion criteria for each group is included in ct.gov Hypoglycemia is a major barrier to the achievement of adequate glycemic control for most patients with insulin-dependent diabetes. Type 1 diabetic patients with absolute insulin deficiency (C-peptide negative) are at greatest risk for experiencing severe hypoglycemic events because the near total destruction of insulin producing islet β-cells produces an associated defect in glucagon secretion from neighboring α-cells. Such patients then depend on the sympathoadrenal system as a final defense against hypoglycemia, but unfortunately, recurrent episodes of hypoglycemia blunt sympathoadrenal activation and produce a syndrome of hypoglycemia unawareness that is associated with a twenty-fold increased risk of life-threatening hypoglycemia. Without intact islet or sympathoadrenal (especially epinephrine) responses to hypoglycemia, these patients cannot increase endogenous (primarily hepatic) glucose production to prevent or correct low blood glucose.

Conditions

• Hypoglycemia Unawareness
• Type 1 Diabetes
• Healthy

Interventions

Type	Name	Description
DEVICE	RT-CGM	Each device is approximately the size of a pager and transmits with a subcutaneously placed sensor consisting of a 21 - 26 gauge needle 5 - 12 mm in length. Sensors are placed using sterile precautions and changed every 3 - 7 days depending on the manufacturers' instructions. All devices are approved as adjunctive tools to blood glucose monitoring that will be continued at least 4 times daily, before each meal and at bedtime.

Timeline

• Start date: 2011-10-01
• Primary completion: 2016-05-01
• Completion: 2021-03-05
• First posted: 2011-11-18
• Last updated: 2023-08-31
• Results posted: 2023-08-31

Locations

3 sites across 1 country: United States