Closed-loop Control of Postprandial Glucose Levels in Children and Adults With Type 1 Diabetes

Summary

Current intensive insulin therapy in T1D involves prandial insulin boluses depending on the carbohydrate content of each ingested meal. Carbohydrate content of ingested meals is the main determinant of post-meal glucose excursion. Therefore, accurate carbohydrate counting is a critical aspect of managing postprandial blood glucose levels in type 1 diabetes in order to avoid too much or too little insulin resulting in hypoglycemia and hyperglycemia, respectively. Precision of carbohydrate counting is associated with better glycemic control. However, accurate carbohydrate counting is a challenging task for many patients with type 1 diabetes. Recent developments of continuous glucose sensors and insulin infusion pumps have motivated the research toward "closed-loop'' strategies to regulate glucose levels in patients with type 1 diabetes. In a closed-loop strategy, the pump insulin infusion rate is altered based on a computer generated recommendation that rely on continuous glucose sensor readings. A dual-hormone closed-loop strategy has also been recently proposed to regulate glucose levels. In a dual-hormone strategy, subcutaneous insulin delivery is accompanied by subcutaneous glucagon infusion. Postprandial meal glucose control with closed-loop strategy still needs some improvements. The objective of this study is to test in outpatient unrestricted settings whether, in the context of closed-loop strategy, conventional meal carbohydrate counting could be reduced to a simplified qualitative meal size estimation without a significant degradation in overall glycemic control in children and adult patients with type 1 diabetes. The investigators hypothesize that 1) dual-hormone closed-loop strategy with qualitative meal size estimation is equivalent to dual-hormone closed-loop strategy with CHO counting in terms of mean glucose; 2) single-hormone closed-loop strategy with qualitative meal size estimation is equivalent to single-hormone closed-loop strategy with CHO counting in terms of mean glucose;

Conditions

• Type 1 Diabetes

Interventions

OTHER

6-day intervention with sensor-augmented pump therapy

One day prior to the intervention, participants will have to install a glucose sensor and the study insulin pump. Participants will adjust their insulin delivery as per their standard practice; including temporary basal and correction boluses. Participants will have access to their finger-stick glucose measurements and will be advised to measure their glucose level as per their standard practice. Participants will be asked to install a new infusion set every 2 days. Participants will be allowed to eat whatever they want and allowed to drink alcohol. Participants will use sensor-augmented pump therapy for 6 days.

OTHER

6-day intervention with single-hormone closed-loop strategy

One day prior to the intervention, participants will have to install a glucose sensor and the study insulin pump. On the first day of the intervention, participants will be admitted to the clinical research facility in the morning. A team member will review with the participant how to use study devices. Competency on the use of study devices will be assessed by a team member. Only participants demonstrating competency on use of study devices will be allowed to continue to the home study phase. Participants will be allowed to go home in the afternoon. They will be advised to continue with study intervention at home for the next 5 days. Participants will be asked to install a new infusion set every 2 days. Participants will be allowed to eat whatever they want and allowed to drink alcohol.

OTHER

6-day intervention with dual-hormone closed-loop strategy

One day prior to the intervention, participants will have to install a glucose sensor and the study insulin pump. On the first day of the intervention, participants will be admitted to the clinical research facility in the morning. Participants will have to install a second pump containing glucagon. A team member will review with the participant how to use study devices. Competency on the use of study devices will be assessed by a team member. Only participants demonstrating competency on use of study devices will be allowed to continue to the home study phase. Participants will be allowed to go home in the afternoon. They will be advised to continue with study intervention at home for the next 5 days. Participants will be asked to install a new infusion set every 2 days. Participants will be allowed to eat whatever they want and allowed to drink alcohol.

DRUG

Insulin

Participant's usual fast-acting insulin analog will be used: Lispro (Humalog), Aspart (NovoRapid) or Glulisine (Apidra)

DRUG

Glucagon

Glucagon (Eli Lilly) will be used during dual-hormone closed-loop strategy.

DEVICE

Continuous Glucose Monitoring System Enlite sensor®, Medtronic

Enlite sensor®, Medtronic

DEVICE

Insulin pump MiniMed® Paradigm® Veo™, Medtronic

MiniMed® Paradigm® Veo™, Medtronic

Sponsors & Collaborators

• Juvenile Diabetes Research Foundation

  collaborator OTHER

• Institut de Recherches Cliniques de Montreal

  lead OTHER

Principal Investigators

• Rémi Rabasa-Lhoret · Institut de recherches cliniques de Montréal

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

CROSSOVER

Eligibility

Min Age

8 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2018-01-31

Primary Completion

2018-07-31

Completion

2018-07-31

Countries

• Canada

Study Locations