Dissertation Defence: The Effects of Different Types, Intensities and Patterns of Exercise on Glycemic Control and its Determinants in Individuals Living with Type 2 diabetes
June 27 at 2:00 pm - 6:00 pm
Jonathan Low, supervised by Jonathan Little & Ali McManus, will defend their dissertation titled “THE EFFECTS OF DIFFERENT TYPES, INTENSITIES, AND PATTERNS OF EXERCISE ON GLYCEMIC CONTROL AND ITS DETERMINANTS IN INDIVIDUALS LIVING WITH TYPE 2 DIABETES” in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Kinesiology.
An abstract for Jonathan Low’s dissertation is included below.
Examinations are open to all members of the campus community as well as the general public. This examination will be offered in a hybrid format. Registration is not required for in-person defences. Please email jonathan.little@ubc.ca to receive the Zoom link for this defence.
Abstract
Problem
Exercise improves glycemic control and lowers mortality risk in type 2 diabetes (T2D). However, knowledge gaps persist regarding how exercise quality and quantity impact glycemic control, especially in real-world settings. Similarly, while a single bout of exercise is known to enhance glycemic control, its magnitude and sustainability outside controlled environments require further investigation.
Aims
This dissertation aims to: i) examine the effects of different types, intensities, and patterns of exercise on glucose homeostasis (Studies 1, 2 and 3) and ii) investigate the changes in blood biomarkers of cardiometabolic health in response to exercise training and evaluate the feasibility of free-living blood collection and delivery for assessing glucose control a real-world exercise intervention (Study 4).
Methods
Three of the four studies (Studies 1,2,4) of this PhD utilized data from a large (n=120), multi-site pilot randomized controlled trial investigating a 26-week mHealth exercise intervention. These studies examined how different exercise parameters (duration, volume, intensity, consistency) influenced glycemic control across the 26-week exercise intervention, investigated if there were differences in glycemic control on exercise vs. non-exercise days in a real-world setting, and assessed the feasibility of remote blood collection to measure glucose control across the Canada-wide intervention. Study 3 was a secondary analysis of a semi-randomized acute cross-over study and explored if different patterns of high-intensity interval training (HIIT) impacted beta-cell function and insulin sensitivity – the key physiological determinants of glucose control.
General Conclusions
Average exercise duration and total exercise accumulated during the first 13 weeks of the 26-week intervention predicted HbA1c, SD and mean 24-hour glucose at the end of the 26-week mHealth exercise intervention. In this real-world setting, individuals living with newly diagnosed T2D had improved glycemic control in the 24-hour period after a bout of exercise as compared to days when they did not perform exercise. In a laboratory setting, an acute bout of 4 X 4-minute or 10 X 1-minute HIIT improved beta cell glucose sensitivity in females living with T2D when compared to a seated control condition. As part of an exercise intervention in T2D, it appeared feasible for a diverse group of participants from across Canada to collect capillary blood and return by mail for remote assessment of glucose control via HbA1c.
