Doctor of Philosophy in Experimental Medicine (PhD)
Assessment of Physical Activity and Sedentary time in South Asian adults at risk for diabetes
BACKGROUND: The effects of peer support (PS) on clinical and psychosocial outcomes has been extensively studied in patients with type 2 diabetes, but only minimally examined in the peer leaders (PLs) who deliver support. This thesis’s objectives are to: examine PLs’ sociodemographic and personality characteristics, assess the clinical and psychological benefits of providing support; and identify strategies to improve PS interventions. METHODS: A sequential explanatory mixed-methods research design approach was utilized. The studies conducted for this thesis were extensions of a larger randomized controlled trial assessing the impact of PS on diabetes-related health outcomes. Fifty-two recruits completed PL training and were matched with participants on schedule availability, gender preference, and geographic proximity. PLs and participants had an initial face-to-face meeting, then weekly phone contacts in the first 3 months and bi-weekly phone contacts in the last 9 months. PLs underwent health-related assessments at baseline, 3, and 12 months. The primary outcomes were A1C and diabetes distress (DD). At study completion, PLs were deemed effective if their participants sustained and/or improved A1C and DD from baseline. The PLs’ sociodemographic and personality characteristics were also measured. To explore PLs’ perspectives, 17 PLs were subsequently invited for semi-structured interviews. RESULTS: PLs’ A1C and DD remained stable over the course of the intervention. Effective PLs had significantly lower baseline DD and significantly higher extraversion than ineffective PLs. During the interviews, PLs characterized their experiences with participants as positive, mutually beneficial, and helpful with diabetes management. Suggestions were that PLs be vigorously screened and that the PL-participant matching process take shared characteristics (e.g., demographic characteristics, diabetes-related commonalities, and life experiences) into account. Traits of successful PLs were also identified.CONCLUSION: Delivering PS interventions may offer clinical and psychosocial benefits to the providers themselves. Further research is warranted with regard to the PL recruitment and matching process to maximize benefits for PLs and participants.
Background and Objective: South Asians develop cardiovascular risk factors and Type 2 diabetes earlier and at lower body mass index (BMI) compared to other ethnic populations in Canada. Diet is a modifiable risk factor. Adherence to a vegetarian diet has been associated with a favourable cardiometabolic profile including body weight, blood pressure, cholesterol, and glycemic control compared to an omnivorous diet. Despite having the greatest proportion of vegetarians in the world, South Asians have amongst the highest rates of diabetes in Canada. This study aims to examine vegetarian dietary intake, explore the relationship between vegetarianism and adiposity, and identify associations between sociodemographic characteristics and adiposity measures in South Asians living in Metro Vancouver. Methods: Using the American Diabetes Association Diabetes Risk Test, 100 South Asian adults identified to be high risk for diabetes were recruited from 12 faith-based centres in Metro Vancouver. 96 participants completed a 163-item culturally tailored food frequency questionnaire and vegetarian status was determined. Waist circumference (WC) and BMI were measured to evaluate adiposity. Dietary intake including calories, macronutrient and micronutrient consumption were compared between vegetarians and omnivores. Associations between diet and sociodemographic characteristics with adiposity markers were examined. Results: 50 participants identified as vegetarian and 46 as omnivore. Vegetarians more frequently consumed carbohydrates and foods with higher glycemic load and glycemic index. Omnivores reported higher intake of several micronutrients (niacin, vitamin B-12, potassium, and zinc), but both diet groups did not meet their nutrient requirements for niacin, potassium and vitamin D. 90.6% of all participants had overweight/obese BMI and a vegetarian diet was not associated with improved adiposity. Female sex and education were positively associated with BMI, while age was associated with higher WC. Conclusion: In addition to the high prevalence of overweight and obesity, both vegetarians and omnivores had dietary intake that may be associated with increased diabetes risk. Factors such as age, socioeconomic status, and Westernization may account for the unhealthy dietary intake observed in this study. Findings demonstrate that promoting healthy nutrition is a priority for this community, and interventions should be tailored to address culture-specific dietary habits in South Asian Canadians.
Background: Live 5-2-1-0 is a community-based childhood obesity prevention initiative that promotes the message: 5+ vegetables/fruits;