Doctor of Philosophy
Introduction: The overall objectives of this dissertation are to 1) summarize the relationship between sedentary behaviour (SB) and cardiometabolic health and 2) develop an effective, feasible, and acceptable intervention to reduce/ break up SB in adults with T2D.
Methods: Objective 1 was fulfilled by conducting an umbrella review on the relationship between SB and cardiometabolic health. Objective 2 was accomplished by conducting a systematic review on interventions that aim to reduce/ break up SB in adults with T2D, qualitatively exploring the perceptions of adults with T2D, and piloting a 6-week (6-week follow-up) mHealth HAPA-based intervention in adults with T2D.
Results: The umbrella review (N=63) suggest that SB is associated, independent of physical activity (PA), with cardiometabolic diseases and biomarkers. The systematic reviews’ (N=22) meta-analysis of short-term SB interventions found significant improvement in glucose compared to control (SMD -0.819, 95% CI -1.255, -0.383, p
Conclusions: SB is associated, independent of PA, with cardiometabolic diseases and biomarkers. Reducing SB appears to be a feasible/ acceptable/ sustainable behaviour change in adults with T2D that could lead to improvements in their glycemic control and thus, should continue to be investigated.
Summary for Lay Audience
Introduction: Adults with type 2 diabetes (T2D) sit more than those without T2D. The overall objectives of this thesis are to 1) summarize the relationship between sitting time (ST) and health 2) develop a good way to reduce ST in adults with T2D.
Methods: Objective 1 was fulfilled by conducting a review on the relationship between ST and health. Objective 2 was fulfilled by conducting a review on studies that tried to reduce/ break up ST in adults with T2D, interviewing adults with T2D, and conducting a 6-week (with 6-week follow-up) theory-based study in adults with T2D.
Results: The first review (N=63) suggest that ST is linked with diseases (i.e., T2D) and markers of disease (i.e., blood sugar) independent of physical activity (PA). The second reviews (N=22) suggests that in the short-term (N=13, days) breaking up ST can improve in blood sugar. Also, in the longer-term (N=8, weeks-years) reducing/breaking up ST is both possible and can lead to improvements in health. The interview study found that adults with T2D view 1) T2D as having an impact on their health, 2) PA and ST as important health behaviours, 3) more barriers for increasing PA than reducing/breaking up ST, and 4) no one size fits all approach for changing PA and ST. The theory-based study in adults with T2D (n=10) produced large non-statistical changes in ST that favoured the theory group. Further, participants felt the study was effective in reducing/ breaking up their ST and would recommend it to others.
Conclusions: ST is linked, independent of PA, with diseases and markers of disease. Reducing/ breaking up ST may be an easy, acceptable, and maintainable change in adults with T2D that could lead to improvements in their blood sugar and overall health and thus, should continue to be studied.
LeSarge, Siobhan, "“Standing Up” to Type 2 Diabetes" (2023). Electronic Thesis and Dissertation Repository. 9357.
Available for download on Friday, May 23, 2025