Clinical trial NCT01519102: Comparison of Closed-loop Operation After Morning Meal With and Without Carbohydrate Counting
Official title: An Open-label, Randomized Two-way, Cross-over Study to Compare Meal-and-carbohydrate-announcement Strategy Versus Meal-announcement Strategy During Closed-loop Regulation of Glucose Levels in a Morning Meal in Adults With Type-1 Diabetes.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: Type-1 Diabetes
Lead sponsor: Institut de Recherches Cliniques de Montreal
Sponsor class: OTHER
Collaborators: name: McGill University
name: Montreal Children's Hospital of the MUHC
First posted: 2012-01-26
Enrollment: 12
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: TREATMENT

Brief summary: 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 dosage based on the sensor's readings. A dual-hormone closed-loop system would regulate glucose levels through the infusion of two hormones: insulin and glucagon.

The main goal of this project is to assess whether a dual-hormone closed-loop strategy would alleviate the burden of carbohydrate counting from patients with type 1 diabetes (T1D) without a significant degradation in post-meal glucose control.

Each patient will be admitted twice to a clinical research facility. In one visit, patients will eat a morning meal accompanied with a matching insulin bolus (depending on the carbohydrate content of the meal) and glucose levels will be subsequently regulated using dual-hormone closed-loop system. In the other visit, patients will eat the same meal but will inject only a partial insulin bolus (not depending on carbohydrate content of the meal) and the remaining needed insulin will be delivered based on glucose sensor excursions as part of closed-loop operation. If post-meal glucose levels were indifferent between the two visits, then this would suggest that carbohydrate counting may not be necessary during closed-loop operation as the closed-loop system will give any remaining insulin needed to cover the glucose absorbed from the meal. Twelve subjects will be enrolled in this study.


Eligibility criteria: Inclusion Criteria:

* Males and females ≥ 18 and ≤ 65 years of old.
* Clinical diagnosis of type 1 diabetes for at least one year. The diagnosis of type 1 diabetes is based on the investigator's judgment and medical history (e.g. history of acido-ketosis, etc.); C peptide level and antibody determinations are not needed.
* The subject will have been on insulin pump therapy for at least 3 months.
* Last (less than 3 months) HbA1c ≤ 12%.

Exclusion Criteria:

* Clinically significant nephropathy, neuropathy (especially clinically significant gastroparesis) or retinopathy as judged by the investigator.
* Recent (\< 3 months) acute macrovascular event e.g. acute coronary syndrome or cardiac surgery.
* Pregnancy.
* Severe hypoglycemic episode within two weeks of screening.

  • Medication likely to affect with the interpretation of the results: Prandase, Victoza, Byetta and Symlin
* Known or suspected allergy to the trial products or meal contents.
* Other serious medical illness likely to interfere with study participation or with the ability to complete the trial by the judgment of the investigator.
* Failure to comply with team's recommendations (e.g. not willing to eat snack, not willing to change pump parameters, etc).
* Unreliable carbohydrate counting
* Problems with venous access

Primary outcomes:
measure: Incremental area under the curve of plasma glucose concentration as compared to pre-meal glucose value of the postprandial glucose excursions
timeFrame: 0-300min
Secondary outcomes:
measure: Percentage of postprandial time of plasma glucose concentrations spent in the high range (above 10.0 mmol/l).
timeFrame: 0-300 min
measure: Mean plasma glucose concentration.
measure: Total insulin delivery
measure: Total glucagon delivery
measure: Plasma glucose concentration and incremental plasma glucose concentration at 2 hours postmeal
measure: Postprandial peak and incremental postprandial peak of plasma glucose concentration
measure: Percentage of time of plasma glucose concentrations spent in target range. Target range is defined to be between 4.0 and 10.0 mmol/l for 150 minutes postmeal and between 4.0 and 8.0 mmol/l afterwards
measure: Percentage of postprandial time of plasma glucose concentrations spent in the low range (below 4.0mmol/l)
timeFrame: 0-300min
Other outcomes:
Locations:
city: Montreal
country: Canada
facility: Institut de Recherches Cliniques de Montréal (IRCM)
state: Quebec
Study officials:
References:
citation: Haidar A, Farid D, St-Yves A, Messier V, Chen V, Xing D, Brazeau AS, Duval C, Boulet B, Legault L, Rabasa-Lhoret R. Post-breakfast closed-loop glucose control is improved when accompanied with carbohydrate-matching bolus compared to weight-dependent bolus. Diabetes Metab. 2014 Jun;40(3):211-4. doi: 10.1016/j.diabet.2013.12.001. Epub 2014 Mar 19.