Hypoglycemia Prevention After Exercise in Adolescent T1DM Patients Using a Control to Range System

Not Applicable

Completed

Conditions: Type 1 Diabetes Mellitus

Interventions: Device: Open-Loop
Device: Closed-Loop

Registration Number: NCT01390259

Lead Sponsor: University of Virginia

Brief Summary: In this protocol the investigators plan to demonstrate management of glucose using a modular insulin management system based on continuous glucose monitoring and targeted towards the avoidance of hypoglycemic and prolonged hyperglycemic episodes (i.e. control to range). The protocol is designed to challenge the insulin management system with meals and mild exercise, so as to demonstrate its capacity to avoid large glucose excursion with changing metabolic state. This system is designed to both

* monitor the meal boluses of the patient and correct it in case of observed/predicted under insulinization (avoidance of prolonged hyperglycemia), based on a coarse and subjective knowledge of the meal amount, a precise understanding of the subject's day to day insulin treatment, continuous glucose monitoring, and past insulin injections;

* predict and avoid hypoglycemic events, based on continuous glucose reading and past insulin injection.

The investigators plan to enroll 12 adolescent T1DM patients (expected retention 10/12) and compare glucose control performances under two treatments: standard vs. the new insulin management system. The protocol will include a total of 5 admissions per subject (3 out-patients and 2 in-patients): screening, CGM insertion 1, CGM insertion 2, inpatient 1 and inpatient 2. During the 24h inpatient admissions the patients will be challenged with 30 minutes of mild exercise and 3 meals, insulin coverage of these events will vary depending on the chosen treatment, each subject will be exposed to both studied treatments (repeated measure design). The order of treatment during the inpatient admissions will be randomized.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 11

Inclusion Criteria

12 years of age and up to and including 18 years of age.
Have type 1 diabetes mellitus as defined by American Diabetes Association criteria or judgment of physician for at least 1 year (including those who may also be treated with metformin).
Use of an insulin pump
If on antihypertensive, thyroid, anti-depressant or lipid lowering medication, have stability on the medication for at least 2 months prior to enrollment in the study
Willingness to use lispro (Humalog) insulin for the duration of the inpatient study
Demonstration of proper mental status and cognition for the study
Willingness to stop using any dietary supplements for two weeks prior to admission and for the duration of their participation
HemoglobinA1c < 10.0
A score of 2 or greater on the hypoglycemia unawareness scale, see Attachment A
Tanner Stage II or greater (not pre-pubertal) on screening physical exam
Body weight of 30 kg or more at screening
BMI must be under 95th percentile for age based on published BMI reference standards

Exclusion Criteria

Age <12 or >18
Pregnancy
Hematocrit <37% (females); <36% (males)
HemoglobinA1c ≥ 10.0
Any symptomatic coronary artery disease, or a history of congenital heart abnormalities.
Score of less than 2 on the hypoglycemia unawareness scale
Tanner Stage I on screening physical exam
Use of a medication that significantly lowers heart rate (beta blockers, reserpine, guanethidine, methyldopa, clonidine, cimetidine, digitalis, calcium channel blockers, amiodarone, antiarrythmic drugs, or lithium)
Congestive heart failure
History of a cerebrovascular event
Use of a medication that significantly impacts glucose metabolism (oral steroids)
Atrial fibrillation
Uncontrolled hypertension (resting blood pressure >140/90)
History of a systemic or deep tissue infection with methicillin-resistant staph aureus or Candida albicans
Use of a device that may pose electromagnetic compatibility issues and/or radiofrequency interference with the FreeStyle NavigatorTM CGM or DexCom Seven® (implantable cardioverter-defibrillator, electronic pacemaker, neurostimulator, intrathecal pump, and cochlear implants)
Active enrollment in another clinical trial
Allergy or adverse reaction to lispro insulin
Known adrenal gland problem, pancreatic tumor, or insulinoma
Current alcohol abuse by patient history, substance abuse by patient history, or severe mental illness
Retinopathy and renal failure
Uncontrolled anxiety or panic disorder
Known bleeding diathesis or dyscrasia
Renal insufficiency (creatinine >1.5)
Any comorbid condition affecting glucose metabolism
Body weight of less than 30 kg at screening
BMI equal to or greater than 95th percentile for age based on published BMI reference standards. See Appendix B.
Asthma or exercise -induced asthma
Any mobility-restrictive condition
Children who are wards of state or at high risk for becoming wards of state

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Open Loop	Open-Loop	The subject were in charge of their insulin treatment.
Closed Loop Control (CLC)	Closed-Loop	The CLC used a computer to make recommendations for their insulin treatment. This study arm was designed to demonstrate management of glucose using a modular insulin management system based on continuous glucose monitoring and targeted towards the avoidance of hypoglycemic and prolonged hyperglycemic episodes (i.e. control to range). This system was designed to both: * monitor the meal boluses of the patient and correct it in case of observed/predicted under insulinization (avoidance of prolonged hyperglycemia), based on a coarse and subjective knowledge of the meal amount, a precise understanding of the subject's day to day insulin treatment, continuous glucose monitoring, and past insulin injections; * predict and avoid hypoglycemic events, based on continuous glucose reading and past insulin injection.

Primary Outcome Measures

Name	Time	Method
Hypoglycemic Events	22 hours	Number of hypoglycemic events below 70 mg/dL per patient per day Hypoglycemic event is defined as consecutive YSI plasma glucose measurements below 70 or moderate hypoglycemic symptoms

Secondary Outcome Measures

Name	Time	Method
Percent Time in Euglycemia	22 hours	Percent of time the patient plasma glucose as measured by YSI is between 70mg/dl and 180mg/dl
Mean Glucose	22 hours	Average plasma glucose concentration in mg/dl