COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC:

Get the latest research information from NIH: Menu

Suspending Basal Insulin Levels for Exercise in Adults With Type 1 Diabetes

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT03034798
Recruitment Status : Completed
First Posted : January 27, 2017
Last Update Posted : January 27, 2017
Illinois Institute of Technology
Information provided by (Responsible Party):
Michael Riddell, York University

Brief Summary:
The purpose of the study is to determine the effects of insulin suspension at start of exercise in individuals with type 1 diabetes. A total of 3 sessions will be required for this project. The first will be a familiarization session that requires completed informed consent, anthropometric measurements (height, weight, body fat percentage), questionnaires, and a test of maximal aerobic fitness. The remaining 2 sessions will be steady-state aerobic exercise as well as circuit exercise.

Condition or disease
Type1 Diabetes Mellitus Physical Activity Hypoglycemia

Detailed Description:

Written informed consent will be collected on the first day during the familiarization session from all individuals that wish to participate. A researcher will provide a brief explanation on how the continuous glucose monitor (CGM) works (Medtronic Inc., Canada) during the first visit to the laboratory. They will also describe how the CGM sensor insertion process will occur for those participants who have not worn one in the past. The participant will clean and sanitize the area and insert the CGM superficially in the skin themselves and connect the transmitter device to the sensor. The CGM will be worn for a total of 7 days and then removed by the participant and returned to the researcher to be downloaded. The sports armband will also be placed on the left upper arm and be worn continuously for 7 days. The principal student investigator (PSI) or principal investigator (PI) will provide all participants with information about the sports armband and place it on the skin immediately following. This device simply sits on the surface of the skin, but has a specific placement and activation and must be applied by the PSI or PI. Finally, during exercise visits, the Zephyr bioharness will be connected just below chest level and around the rib cage. This device is sits on top of the skin simply like an elastic band around the rib cage. The bioharness will only be worn during exercise visits and disconnected at the end of each activity.

Blood glucose levels will be monitored frequently during exercise using a Contour Link glucometer (Bayer, Canada). Participants will use personal lancing device for finger pokes, but the investigators will provide the glucometer and test strips. Each blood sugar check will be recorded in the data binder along with carbohydrate intake, any changes in basal rate or pump settings, and food intake. If blood glucose levels reach 3.9 mmol/L or less, participants will be asked to stop activity immediately and consume fast-acting carbohydrates (i.e. Dextrose tablets (Dex4, USA)). 15-minutes after ingestion of carbohydrates, blood glucose will be tested again before allowing the individual to return to activity safely. On the last day of testing, participants will be asked to return the CGM, sports armband, and bioharness to the research team. The data will later be uploaded and analyzed.

Patients will undergo a fitness assessment (maximal aerobic capacity) during visit 1 and perform 40-minutes of continuous (treadmill jogging) and 40-minutes of intermittent (calisthenics) high-intensity type exercises (visit 2 and 3). Upon entry to the laboratory, participants will be asked to check blood glucose levels using the glucometer provided. The first exercise session will consist of a 40-minute treadmill walk/jog at ~40-50% of VO2max. The second exercise session will include various aerobic and anaerobic activities including push-ups, plank, jumping jacks, high knees, etc. Regular finger capillary blood samples will be collected every 10-minutes during exercise. Once the exercise session is complete, participants will be asked to remain in the laboratory for 30-minutes for additional blood glucose measurements and to ensure hypoglycemic episodes do not occur post-exercise. Participants will be given the contour link glucometer to monitor glucose levels throughout the evening and night.

Layout table for study information
Study Type : Observational
Actual Enrollment : 12 participants
Observational Model: Case-Crossover
Time Perspective: Prospective
Official Title: The Effects of Basal Insulin Suspension at the Start of Exercise on Blood Glucose Levels During Continuous vs. Circuit-based Exercise in Individuals With Type 1 Diabetes on CSII
Actual Study Start Date : January 14, 2015
Actual Primary Completion Date : July 28, 2016
Actual Study Completion Date : July 28, 2016

Resource links provided by the National Library of Medicine

Type 1 Diabetes Exercisers
Participants performed 2 different forms of exercise of identical duration and similar total energy expenditure. One form was purely aerobic in nature and the other was intermittent, high-intensity exercise.

Primary Outcome Measures :
  1. Blood glucose concentrations [ Time Frame: Approximately 2 hours ]
    Whole blood glucose concentrations were measured using a handheld glucometer every 10-minutes before, during, and after both exercise conditions.

Secondary Outcome Measures :
  1. Participants estimated blood glucose concentration [ Time Frame: 40-minutes during exercise and 10-minutes post-exercise ]
    Whole blood glucose concentrations were measured using a handheld glucometer and the values were blinded from participants during exercise. Participants were asked to estimate the change in glycemia every 10-minutes and actual measured blood glucose was revealed to participants post-exercise.

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

Layout table for eligibility information
Ages Eligible for Study:   18 Years to 55 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Probability Sample
Study Population
Participants were recruited by random sampling as well as an email blast using previous studies that involved individuals with type 1 diabetes on insulin pump therapy and regularly active. The previous research project at York University had the same inclusion criteria, so that email list will be used to contact those individuals for this study as well.

Inclusion Criteria:

  • Have had diabetes for > 1 year
  • Currently treated with continuous subcutaneous insulin infusion (CSII)/insulin pump therapy for at least 6 months
  • Fair-to-good glycemic control (last HbA1c ≤ 9.0%)

Exclusion Criteria:

  • Frequent and unpredictable hypoglycemia
  • Unable to exercise on a regular basis due to an injury or other restriction
  • Using an insulin pump and switch to injections (or vice versa) in the last two months
  • Have conditions that would make exercise unsafe (e.g. high blood pressure)
  • Take medications in the class of drugs called 'beta-blockers'
  • A woman who is pregnant, planning pregnancy, or breastfeeding

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03034798

Sponsors and Collaborators
York University
Illinois Institute of Technology
Layout table for investigator information
Principal Investigator: Michael C Riddell, PhD York University
Publications of Results:
Layout table for additonal information
Responsible Party: Michael Riddell, Professor, York University Identifier: NCT03034798    
Other Study ID Numbers: 1DP3DK101075 ( U.S. NIH Grant/Contract )
First Posted: January 27, 2017    Key Record Dates
Last Update Posted: January 27, 2017
Last Verified: January 2017
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Layout table for additional information
Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
Layout table for MeSH terms
Diabetes Mellitus
Diabetes Mellitus, Type 1
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases
Autoimmune Diseases
Immune System Diseases