Closed-loop system systems that are shown to alleviate the burden of carbohydrate counting without degrading glucose control are still lacking. In this proposal, the investigators aim to develop a novel, fully-automated, closed-loop system that delivers insulin and pramlintide that controls postprandial glucose levels without any input from the user.
Meal carbohydrate content is the main determinant of prandial insulin needs, and consequently, accurate carbohydrate counting is recommended for type 1 diabetes. Advances in glucose sensors have motivated the development of the closed-loop system to automatically regulate glucose levels in individuals with type 1 diabetes. In the closed-loop system, a dosing algorithm adjusts the pump insulin infusion rate based on continuous glucose sensor readings. Closed-loop system systems that are shown to alleviate the burden of carbohydrate counting without degrading glucose control are still lacking. In this proposal, the investigators aim to develop a novel, fully-automated, closed-loop system that delivers insulin and pramlintide that controls postprandial glucose levels without any input from the user. Thus, the two hormones' role in the postprandial state will be as follows: 1. Insulin: to reduce plasma glucose levels. Insulin delivery needs to be aggressive to counter-act fast increase in post-meal glucose levels. 2. Pramlintide: to slow gastric emptying and aim insulin in efficiently controlling postprandial glucose levels. The aim of this study is to assess a fully automated, dual-hormone, closed-loop system that delivers insulin, and pramlintide to control glucose levels without degrading overall glycemic control compared to an insulin-alone closed-loop system with carbohydrate-matched boluses. The investigators hypothesize that the dual-hormone closed-loop system will alleviate carbohydrate-counting burden (fully reactive system) without degrading glucose control compared to the insulin-alone closed-loop system.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
24
Subjects will be admitted at the research facility at 19:00. Each 27-hour intervention visit includes 3 standardized meals (8:00, 12:00, and 17:00), an evening snack (22:00) and an overnight stay. The glucose level as measured by the real time sensor will be entered manually into the computer every 10 minutes. The infusion rate of either insulin alone or insulin and pramlintide will be changed manually based on the computer generated recommendation. The computer generated recommendations are based on a predictive algorithm.
McGill University Health Centre
Montreal, Quebec, Canada
Total percentage of time (22:00-22:00) that the glucose concentration remained within 3.9 and 10.0 mmol/L
Time frame: 24 hours
Total percentage of time (22:00-22:00) that the glucose concentration remained within specified ranges.
a. between 3.9 and 7.8 mmol/L; b. below 3.9 mmol/L; c. between 3.9 and 10 mmol/L d. below 3.3 mmol/L; e. below 2.8 mmol/L; f. above 7.8 mmol/L; g. above 10 mmol/L; h. above 13.9 mmol/L; i. above 16.7 mmol/L.
Time frame: 24 hours
Percentage of overnight time (24:00-8:00) that the glucose concentration remained within specified ranges.
a. between 3.9 and 7.8 mmol/L; b. between 3.9 and 10 mmol/L; c. below 3.9 mmol/L; d. below 3.3 mmol/L; e. below 2.8 mmol/L; f. above 7.8 mmol/L; g. above 10 mmol/L; h. above 13.9 mmol/L; i. above 16.7 mmol/L.
Time frame: 8 hours
Total amount of insulin delivered to the participant
Time frame: 24 hours
Mean sensor glucose concentration during the overnight stay
Time frame: 8 hours
Number of participants experiencing hypoglycemia requiring oral treatment during: a. the overall study period; b. the night; c. the day
Time frame: 27 hours
The number and severity of gastrointestinal sysmptoms experienced by a participant
GI symptoms include: nausea, vomiting, bloating and heartburn
Time frame: 27 hours
Mean daytime insulin concentration
Time frame: 14 hours
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Mean daytime concentration of amylin
Time frame: 14 hours
Total amount of pramlintide delivered to the participant
Time frame: 24 hours
Mean glucose level
Time frame: 24-hour period