Repeatability of Blood Glucose Responses to Resistance Exercise in Type 1 Diabetes

Repeatability of Blood Glucose Responses to Fasted and Fed Resistance Exercise in Individuals With Type 1 Diabetes

This study proposes to examine the impact of time of day (morning versus afternoon) on the variability of blood glucose responses to high resistance exercise in a single group of patients with type 1 diabetes. Participants will be asked to wear a continuous glucose monitor during the 3 weeks of testing. During the six exercise sessions (three in the morning while fasted and three in the afternoon), participants will complete the same resistance exercise protocol.

Study Overview

• Status: Completed
• Conditions: Type 1 Diabetes
• Intervention / Treatment: Behavioral: Fasted morning resistance exercise; Behavioral: Afternoon resistance exercise

Detailed Description

Pre-test measures: Interested participants will be invited to the Physical Activity and Diabetes Laboratory on the main campus of the University of Alberta. They will be asked questions related to their physical activity levels and medication, and blood pressure will be measured to assess their eligibility. Where participants are eligible, anthropometric characteristics will be measured using standard protocols, as will blood pressure. A blood sample will be drawn for assessment of HbA1c. Participants will be introduced to the weight lifting equipment and the proper lifting techniques associated with each exercise prior to performing a standardized test to determine the maximum weight they can safely lift eight times while maintaining proper form (8 repetition maximum - 8RM).

Testing sessions: Participants will be asked to arrive at the lab either between 7 and 8 am in a fasting state, or between 4 pm and 5 pm. The three morning and three afternoon testing sessions will have identical exercise protocols. Participants will be asked to perform three sets of eight repetitions of seven different exercises (bench press leg press, shoulder press, leg curl, lat pulldown, abdominal crunches, seated row) at their pre-determined 8RM. Participants will be asked to match their food and insulin intake as closely as possible on testing days to avoid having these as confounders.

A continuous glucose monitor (CGM) sensor will be subcutaneously inserted by one of the investigators (trained by a group from the CGM manufacturer) into the anterior abdominal area of the participant in the morning of the day prior to the first testing session. CGM will store glucose data every 5 minutes for up to 7 days. During this time, participants will be asked to wear an accelerometer to allow for the objective assessment of background physical activity and sleep quality. Along with this device, they will fill out an activity and sleep log to improve the analysis of the data.

• Study Type: Interventional
• Enrollment (Actual): 27
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Edmonton, Alberta, Canada, T6G 2R3
      • Alberta Diabetes Institute

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• type 1 diabetes diagnosed for at least 1 year
• aged 18 to 55 years

Exclusion Criteria:

• HbA1c > 9.9%
• frequent and unpredictable hypoglycemia
• change in insulin management strategy within two months of study
• using closed-loop insulin delivery
• injuries that would contraindicate resistance exercise
• blood pressure > 140/95
• severe peripheral neuropathy
• a history of cardiovascular disease
• severe proliferative retinopathy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: All participants; There is only one study arm consisting of all participants.	Behavioral: Fasted morning resistance exercise; On three separate occasions, participants will perform a standardized resistance exercise protocol in the morning while fasting.; Behavioral: Afternoon resistance exercise; On three separate occasions participants will perform a standardized resistance exercise protocol in the afternoon after eating their regular lunch

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Capillary glucose (change during exercise)	Using test strips and a hand-held glucometer to test blood from a finger poke	0 minutes (exercise start), 15 minutes, 30 minutes, 45 minutes, 60 minutes, 75 minutes, 90 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean CGM glucose	mean CGM glucose	6 hours, 12 hours, overnight (midnight to 6am) and 24 hours post-exercise
CGM coefficient of variation (CV)	coefficient of variation of continuous glucose monitoring data	6 hours, 12 hours, overnight (midnight to 6am) and 24 hours post-exercise
CGM standard deviation (SD)	Standard deviation of CGM glucose	6 hours, 12 hours, overnight (midnight to 6am) and 24 hours post-exercise
frequency of hypoglycemia	number of hypoglycemic events measured by CGM	6 hours, 12 hours, overnight (midnight to 6am) and 24 hours post-exercise
frequency of hyperglycemia	number of hyperglycemic events measured by CGM	6 hours, 12 hours, overnight (midnight to 6am) and 24 hours post-exercise
percent time in range	percent of time spent between 4.0 and 9.9 mmol/L	6 hours, 12 hours, overnight (midnight to 6am) and 24 hours post-exercise
percent time in hyperglycemia	percent of time spent over 10.0 mmol/L	6 hours, 12 hours, overnight (midnight to 6am) and 24 hours post-exercise
percent time in hypoglycemia	percent of time spent below 3.9 mmol/L	6 hours, 12 hours, overnight (midnight to 6am) and 24 hours post-exercise

Collaborators and Investigators

• Sponsor: University of Alberta
• Collaborators: DexCom, Inc.

Study record dates

Study Major Dates

• Study Start (Actual): November 16, 2021
• Primary Completion (Actual): December 16, 2023
• Study Completion (Actual): December 16, 2023

Study Registration Dates

• First Submitted: November 22, 2021
• First Submitted That Met QC Criteria: December 8, 2021
• First Posted (Actual): December 23, 2021

Study Record Updates

• Last Update Posted (Actual): January 5, 2024
• Last Update Submitted That Met QC Criteria: January 3, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Immune System Diseases; Autoimmune Diseases; Endocrine System Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 1
• Other Study ID Numbers: Pro00082031

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No