Trial Outcomes & Findings for Feasibility Study of Closed Loop Control in Type 1 Diabetes Using Heart Rate Monitoring as an Exercise Marker (NCT NCT01582139)

NCT ID: NCT01582139

Last Updated: 2014-08-15

Results Overview

Plasma glucose based number of hypoglycemic events, defined as consecutive plasma readings below 70mg/dl to measure the capacity of the system to protect patients against the risk of hypoglycemia. Two events separated by only one Yellow Springs Instrument (YSI) value over 70 are considered to form a single event.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

12 participants

Primary outcome timeframe

26 hours (x2 admissions)

Results posted on

2014-08-15

Participant Flow

Participant milestones

Participant milestones
Measure
Control First, Then Experimental
Control, SSM+HMM: A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate. Experimental, Heart-Rate Informed SSM: An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate
Experimental First, Then Control
Control, SSM+HMM: A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate. Experimental, Heart-Rate Informed SSM: An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate
Overall Study
STARTED
6
6
Overall Study
COMPLETED
6
6
Overall Study
NOT COMPLETED
0
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Feasibility Study of Closed Loop Control in Type 1 Diabetes Using Heart Rate Monitoring as an Exercise Marker

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Control First, Then Experimental
n=6 Participants
Control, SSM+HMM: A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate. Experimental, Heart-Rate Informed SSM: An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate
Experimental First, Then Control
n=6 Participants
Control, SSM+HMM: A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate. Experimental, Heart-Rate Informed SSM: An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate
Total
n=12 Participants
Total of all reporting groups
Age, Categorical
<=18 years
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Age, Categorical
Between 18 and 65 years
6 Participants
n=5 Participants
6 Participants
n=7 Participants
12 Participants
n=5 Participants
Age, Categorical
>=65 years
0 Participants
n=5 Participants
0 Participants
n=7 Participants
0 Participants
n=5 Participants
Sex: Female, Male
Female
5 Participants
n=5 Participants
2 Participants
n=7 Participants
7 Participants
n=5 Participants
Sex: Female, Male
Male
1 Participants
n=5 Participants
4 Participants
n=7 Participants
5 Participants
n=5 Participants

PRIMARY outcome

Timeframe: 26 hours (x2 admissions)

Population: Twelve subjects completed the study. The first two subjects were excluded from the analysis because of protocol violations during the exercise session (the intensity chosen was very high: rating of perceived exertion of 9 out of 10 instead of rating of perceived exertion of 9 out of 20). Results from the 10 remaining subjects are presented below.

Plasma glucose based number of hypoglycemic events, defined as consecutive plasma readings below 70mg/dl to measure the capacity of the system to protect patients against the risk of hypoglycemia. Two events separated by only one Yellow Springs Instrument (YSI) value over 70 are considered to form a single event.

Outcome measures

Outcome measures
Measure
Experimental: Heart-Rate Informed SSM+HMM
n=10 Participants
An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate Heart rate informed SSM+HMM: The Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) of the Closed Loop is informed about heart rate during exercise. The goal is to demonstrate the feasibility of a modular insulin management system based on continuous glucose monitoring that additionally employs heart rate information to reduce exercise-related hypoglycemic episodes.
Control: SSM+HMM
n=10 Participants
A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate.
Hypoglycemic Events
During Exercise (t=0.5h)
0 hypoglycemic events
2 hypoglycemic events
Hypoglycemic Events
Overnight (t=8h)
0 hypoglycemic events
1 hypoglycemic events
Hypoglycemic Events
During Recovery (t=2.5h)
1 hypoglycemic events
2 hypoglycemic events

SECONDARY outcome

Timeframe: 26 hours (x2 admissions)

Population: Twelve subjects completed the study. The first two subjects were excluded from the analysis because of protocol violations during the exercise session (the intensity chosen was very high: rating of perceived exertion of 9 out of 10 instead of rating of perceived exertion of 9 out of 20). Results from the 10 remaining subjects are presented below.

A measure of the risk of hypoglycemia. It quantifies the frequency and the extent of low BG readings. A LBGI \< 2.5 is associated with a low-risk of hypoglycemia, LBGI 2.5-5 is associated with a moderate risk of hypoglycemia, and LBGI \> 5 is associated with a high-risk of hypoglycemia.

Outcome measures

Outcome measures
Measure
Experimental: Heart-Rate Informed SSM+HMM
n=10 Participants
An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate Heart rate informed SSM+HMM: The Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) of the Closed Loop is informed about heart rate during exercise. The goal is to demonstrate the feasibility of a modular insulin management system based on continuous glucose monitoring that additionally employs heart rate information to reduce exercise-related hypoglycemic episodes.
Control: SSM+HMM
n=10 Participants
A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate.
Low Blood Glucose Index
During Exercise (t=0.5h)
0.84 index score
Standard Error 0.60
2.72 index score
Standard Error 1.61
Low Blood Glucose Index
During Recovery (t=2.5h)
1.81 index score
Standard Error 1.2
1.83 index score
Standard Error 1.4
Low Blood Glucose Index
Overnight (t=8h)
0.98 index score
Standard Error 0.41
0.49 index score
Standard Error 0.21

SECONDARY outcome

Timeframe: 26 hours (2x admissions)

Population: The first two subjects were excluded from the analysis because of protocol violations during the exercise session (the intensity chosen was very high: rating of perceived exertion of 9 out of 10 instead of rating of perceived exertion of 9 out of 20). Results from the 10 remaining subjects are presented.

Average glucose drops at specific time points after the onset of exercise; defined as the difference between plasma glucose at onset of exercise and the glucose values reached at 40 and 60 min post onset of exercise.

Outcome measures

Outcome measures
Measure
Experimental: Heart-Rate Informed SSM+HMM
n=10 Participants
An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate Heart rate informed SSM+HMM: The Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) of the Closed Loop is informed about heart rate during exercise. The goal is to demonstrate the feasibility of a modular insulin management system based on continuous glucose monitoring that additionally employs heart rate information to reduce exercise-related hypoglycemic episodes.
Control: SSM+HMM
n=10 Participants
A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate.
Average Glucose Drop
60 min since exercise onset
-3.4 mg/dL
Standard Deviation 12
-27.7 mg/dL
Standard Deviation 10
Average Glucose Drop
40 min since exercise onset
-5 mg/dL
Standard Deviation 10
-29 mg/dL
Standard Deviation 10

SECONDARY outcome

Timeframe: 26 hours (x2 admissions)

Population: Twelve subjects completed the study. The first two subjects were excluded from the analysis because of protocol violations during the exercise session (the intensity chosen was very high: rating of perceived exertion of 9 out of 10 instead of rating of perceived exertion of 9 out of 20). Results from the 10 remaining subjects are presented below.

Percent time spent within target (70-180 mg/dL) range.

Outcome measures

Outcome measures
Measure
Experimental: Heart-Rate Informed SSM+HMM
n=10 Participants
An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate Heart rate informed SSM+HMM: The Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) of the Closed Loop is informed about heart rate during exercise. The goal is to demonstrate the feasibility of a modular insulin management system based on continuous glucose monitoring that additionally employs heart rate information to reduce exercise-related hypoglycemic episodes.
Control: SSM+HMM
n=10 Participants
A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate.
Time in Range
Overall
81 percentage of time spent in range
Standard Error 3.9
75 percentage of time spent in range
Standard Error 4.3
Time in Range
During Exercise (t=0.5h)
91 percentage of time spent in range
Standard Error 7.3
85 percentage of time spent in range
Standard Error 10.3
Time in Range
During Recovery (t=2.5h)
86 percentage of time spent in range
Standard Error 9.3
84 percentage of time spent in range
Standard Error 7.9
Time in Range
Overnight (t=8h)
89 percentage of time spent in range
Standard Error 7.1
84 percentage of time spent in range
Standard Error 9.2

Adverse Events

Control: SSM+HMM

Serious events: 0 serious events
Other events: 2 other events
Deaths: 0 deaths

Experimental: Heart Rate Informed SSM+HMM

Serious events: 0 serious events
Other events: 1 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Control: SSM+HMM
n=12 participants at risk
A control condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is not informed about heart rate.
Experimental: Heart Rate Informed SSM+HMM
n=12 participants at risk
Experimental: An experimental condition involving an exercise session where the Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) is informed about heart rate Heart rate informed SSM+HMM: The Safety Supervision Module + Hyperglycemic Mitigation Module (SSM+HMM) of the Closed Loop is informed about heart rate during exercise. The goal is to demonstrate the feasibility of a modular insulin management system based on continuous glucose monitoring that additionally employs heart rate information to reduce exercise-related hypoglycemic episodes.
Musculoskeletal and connective tissue disorders
Knee Pain
8.3%
1/12 • Number of events 2
8.3%
1/12 • Number of events 1
Skin and subcutaneous tissue disorders
Mild Erythema
8.3%
1/12 • Number of events 5
0.00%
0/12

Additional Information

Marc D Breton, Ph.D.

University of Virginia

Phone: 434-982-6484

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place