Closed-loop Glucose Control for Automated Management of Type 1 Diabetes

Boston University Charles River Campus

Status

Completed

Conditions

Type 1 Diabetes

Treatments

Device: Closed-loop

Study type

Interventional

Funder types

Other

Identifiers

NCT00811317

SPID#0813

2007P-000101

H-27207

Details and patient eligibility

About

We hypothesize that our integrated closed-loop glucose-control system can provide effective, tight, and safe blood glucose (BG) control in type 1 diabetes, thereby establishing the feasibility of closed-loop BG control.

Full description

This study investigates the utility of an integrated closed-loop glucose-control system for regulating BG in type 1 diabetic subjects. The closed-loop system utilizes sub-cutaneous infusion or insulin and glucagon under the control of a computer algorithm. The only inputs to the algorithm are the subject weight and BG values measured every five minutes. Subjects will undergo up to three 27 hour GCRC admissions during which they will consume three standardized meals. Subject may participate in up to two closed-loop visits (with different insulin lispro pharmacokinetic parameter settings in the control algorithm) and some subjects will participate in open-loop visits. During the closed-loop admission BG will be controlled by the closed-loop system. During the open-loop visit subjects will regulate their own BG in the usual function using their insulin pumps. A small group of non-diabetic subjects will undergo a single 27 hour GCRC admission during which they will eat the same standardized meals. During all admission BG will be measured every 5 minutes and blood will be collected for measurement of insulin and glucagon levels every 10 minutes. During the closed-loop admission of diabetic subjects and the single admission of non-diabetic subjects, three commercially available continuous glucose monitoring devices will be worn. The data from these devices will later be compared to reference BG data.

Enrollment

11 patients

Sex

All

Ages

18+ years old

Volunteers

Accepts Healthy Volunteers

Inclusion and exclusion criteria

Inclusion Criteria (type 1 diabetic subjects):

Age 18 years or older
Clinical type 1 diabetes for at least five years
Otherwise healthy (mild chronic disease allowed if well controlled)
Diabetes managed using an insulin infusion pump
Body mass index (BMI) between 20 and 31
Total daily dose (TDD) of insulin ≤ 1 U/kg and ≤ 100 U/day
Post-prandial C-peptide < 0.1 nmol/L at 90 minutes in a mixed meal (Sustacal) tolerance test by the DCCT method
Hemoglobin A1c less than or equal to 8.5%
Prescription medication regimen stable for at least 1 month

Inclusion Criteria (non-diabetic subjects):

Age 18 years or older
No personal history of diabetes, impaired fasting glucose, or impaired glucose tolerance
No personal history of pancreatic disease
Not taking medication that may affect glucose, insulin, or glucagon dynamics
Otherwise healthy (mild chronic disease allowed if well controlled)
Body mass index (BMI) between 20 and 31
Normal 75 g oral glucose tolerance test (fasting, 1 hour, and 2 hour measurements)

Exclusion Criteria (all subjects):

Unable to provide informed consent or are unable to comply with study procedures
Current participation in another clinical trial
Anemia (HCT or hemoglobin less than normal for sex)
Elevated alanine aminotransferase (ALT > 3 fold above upper limit of normal)
Untreated or inadequately treated hyperthyroidism or hypothyroidism (abnormal TSH or free T4)
Pregnancy (positive urine HCG), breast feeding, plan to become pregnant in the immediate future, or sexually active without use of contraception
Progressive or proliferative diabetic retinopathy (subjects with mild, non-proliferative background retinopathy or stable disease previously treated with photocoagulation are not excluded).
Renal insufficiency (creatinine clearance estimated by Cockcroft-Gault equation of ≤ 50 ml/min)
Any known history or symptoms of coronary artery disease.
Abnormal EKG
Congestive heart failure
History of TIA or stroke within preceding 6 months
Acute illness or exacerbation of chronic illness at the time of the study procedure
Change in medication regimen in the 30 days prior to enrollment
History of seizures
History of pheochromocytoma
Abnormal plasma fractionated metanephrines
History of adrenal disease or tumor
History of pancreatic tumor, including insulinoma
History of impaired gastric motility or gastroparesis requiring pharmacological or surgical treatment
Current alcohol abuse (> 3 drinks daily) or substance abuse (any use within the last 6 months of illegal drugs)
Severe mental illness (schizophrenia, bipolar disease, inadequately treated depression, or any psychiatric hospitalization in the last year)
Impaired cognition or altered mental status.
Hypertension (blood pressure > 140/90) at the time of screening
Use of medications that reduce gastric motility
Electrically powered implants that might be susceptible to RF interference
Use non-insulin injectable anti-diabetic medications, inhaled insulin, or oral anti-diabetic medications
History of adverse reaction to glucagon (including allergy) besides nausea and vomiting.
Established history of latex, adhesive, tape allergy, inadequate venous access, history of allergy to or intolerance of aspirin.