Closed-loop Control of Overnight Glucose Levels in Adults and Adolescents With Type 1 Diabetes

Institut de Recherches Cliniques de Montreal

Status and phase: Completed; Phase 2

Conditions: Type 1 Diabetes

Treatments: Other: Exercise; Other: Carbohydrate-rich meal

Study type: Interventional

Funder types: Other

Identifiers

NCT01905020

CLASS-04

Details and patient eligibility

About

Closed-loop strategy is composed of three components: glucose sensor to read glucose levels, insulin pump to infuse insulin and a dosing mathematical algorithm to decide on the required insulin dosages based on the sensor's readings. A dual-hormone closed-loop system would regulate glucose levels through the infusion of two hormone: insulin and glucagon.

The main objective of this project is to compare the efficacy of single-hormone closed-loop strategy, dual-hormone closed-loop strategy and pump therapy to regulate overnight glucose levels in a out-patient study in adults and adolescents with type 1 diabetes.

The investigators hypothesized that dual-hormone closed-loop strategy is more effective in regulating overnight glucose levels in adults and adolescents with type 1 diabetes compared to single-hormone closed-loop strategy, which in turn is more effective than the conventional pump therapy.

Full description

Closed-loop strategy is composed of three components: glucose sensor to read glucose levels, insulin pump to infuse insulin and a dosing mathematical algorithm to decide on the required insulin dosages based on the sensor's readings. A dual-hormone closed-loop system would regulate glucose levels through the infusion of two hormone: insulin and glucagon.

We aim to conduct a multicenter study to compare the efficacy of conventional pump therapy, single-hormone closed-loop strategy and dual-hormone closed-loop strategy to regulate overnight glucose levels, at home, in adolescents and adults with type 1 diabetes. Each intervention will be tested on two nights: 1) After a carbohydrate-rich dinner meal (to exaggerate hyperglycemic risk and; 2) After an evening exercise (to exaggerate hypoglycemic risk).

Enrollment: 28 patients

Sex: All

Ages: 12+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Males and females aged ≥ 12 years of old.
• Body mass index < 35
• Clinical diagnosis of type 1 diabetes for at least one year.
• The subject will have been on insulin pump therapy for at least 4 months.
• HbA1c < 12%.
• At least two visits with an endocrinology team in the past 1 year.

Exclusion criteria

• Clinically significant nephropathy, neuropathy (peripheral or autonomic e.g. significant gastroparesis) or retinopathy as judged by the investigator.
• Recent (< 6 months) acute macrovascular event e.g. acute coronary syndrome or cardiac surgery.
• A recent injury to body or limb, muscular disorder, use of any medication or other significant medical disorder if that injury, medication or disease in the judgment of the investigator will affect the completion of the exercise protocol.
• Ongoing pregnancy.
• Severe hypoglycemic episode within two weeks of screening.
• Current use of glucocorticoid medication (except low stable dose and inhaled therapy).
• Known or suspected allergy to the insulin aspart, glucagon, Medtronic sensors, or Medtronic infusion sets..
• Other serious medical illness likely to interfere with study participation or with the ability to complete the trial by the judgment of the investigator.
• Anticipating a significant change in treatment regimen between admissions (such as a major change in an exercise routine, significant change in dietary routine or in insulin therapy.
• Failure to comply with team's recommendations.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

---

28 participants in 3 patient groups

Conventional insulin pump therapry

Active Comparator group

Description:

Subjects will use conventional pump therapy to regulate their glucose levels.

Treatment:

Other: Exercise

Other: Carbohydrate-rich meal

Single-hormone closed-loop system

Active Comparator group

Description:

Variable subcutaneous insulin infusion rate will be used to regulate glucose levels. Insulin Aspart (Novorapid) will be infused using a subcutaneous infusion pump. The glucose level as measured by the real time sensor will be entered manually into the computer every 10 minutes. The pump's infusion rate will then be changed manually based on the computer-generated recommendations of infusion rates.

Treatment:

Other: Exercise

Other: Carbohydrate-rich meal

Dual-hormone closed-loop system

Active Comparator group

Description:

Insulin Aspart (Novorapid) and glucagon (Paladin) will be infused using two separate subcutaneous infusion pumps. The glucose levels as measured by the real time sensor will be entered manually into the computer every 10 minutes. The pumps' infusion rate will then be changed manually based on the computer generated-recommendation delivery levels.

Treatment:

Other: Exercise

Other: Carbohydrate-rich meal