An Examination of Sex Specific Differences in Glucose Responses Using the Exercise – Physical Activity and Diabetes Glucose Monitoring (E-PAraDiGM) Protocol

  • Author / Creator
    Rees, Jordan L
  • Background/Objective. Continuous glucose monitors (CGM) allow researchers to examine various aspects of circulating glucose profiles in response to exercise. Exercise studies using CGM in individuals with type 2 diabetes (T2D) vary in regards to the type and timing of exercise, making it difficult to compare inter-individual differences to the same bout of exercise. Furthermore, the majority of acute exercise studies have been conducted in males making it difficult to examine sex specific differences. As a consequence of these challenges, the Exercise-Physical Activity and Diabetes Glucose Monitoring (E-PAraDiGM) Protocol has been proposed and implemented across eight sites in Canada to provide a standardized comparison in prospective exercise studies using CGM. Results from this thesis form the preliminary analysis of the E-PAraDiGM protocol with data collection from the University of Alberta sites. Methods. Twenty participants diagnosed with T2D wore a CGM during the 6-day protocol and standardized meals were provided for 2 conditions (exercise vs. seated control) lasting 2 days each. Conditions were separated by a 72-hour washout period and their order was assigned according to a randomized crossover design. Exercise involved a 50-minute walk at 5.0 km/hr and 0.5% incline (~3.5 metabolic equivalents [METs]) performed 3 – 5 hours after lunch and prior to the evening meal. The 24-hour period following exercise was analyzed and compared to the control condition in which exercise was replaced by a time-matched 50-minute seated control condition. Results. Twenty participants (11 males, 9 females) were recruited and completed the protocol. The meanstandard deviation (SD) for age, time since diagnosis of T2D, and glycated hemoglobin (A1c) were 61.9 9.1 years, 9.3 6.9 years, and 6.8% 0.7%, respectively. On average, exercise did not affect 24-hour mean glucose (exercise 7.0 1.6, control 7.2 1.5, p=0.343) with the difference between the exercise and control conditions ranging from -1.7 mmol/L to +2.0 mmol/L. There was no difference between sexes (p=0.265), and no sex by exercise interaction in 24-hour mean glucose (p=0.300). There was a difference in 50-minute mean glucose during the exercise and seated control conditions (exercise 6.4 1.5 control 7.3 1.6 p<0.0001) and between sexes (males 7.0 1.5 , females 5.6 1.0, p<0.0001). No differences were found between the exercise and seated control conditions or between sexes in time spent above 10 mmol/L or below 4 mmol/L, postprandial glucose, fasting glucose, or glycemic variability. Conclusion. This was the first study to examine sex differences following an acute bout of exercise. Interestingly and contrary to previous findings, there was no effect of exercise on 24-hour mean glucose. Females had lower glucose levels during 50-minutes of exercise compared to males, but no differences were found in other outcome variables. Future analysis using the full E-PAraDiGM sample size will allow for further investigation of sex specific differences. Moreover, the examination of additional predictors of the glycemic responses (e.g. age, medication use, and body composition) to exercise will be examined.

  • Subjects / Keywords
  • Graduation date
    Fall 2017
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
  • Supervisor / co-supervisor and their department(s)
  • Examining committee members and their departments
    • Dr. Carla Prado, Department of Agricultural, Food and Nutritional Science - Division of Human Nutrition
    • Dr. Jane Yardley, Faculty of Physical Education and Recreation
    • Dr. Rhonda Bell, Department of Agricultural, Food and Nutritional Science - Division of Human Nutrition