PhD Oral Exam - Hillary Rowe, Psychology 

When studying for a doctoral degree (PhD), candidates submit a thesis that provides a critical review of the current state of knowledge of the thesis subject as well as the student’s own contributions to the subject. The distinguishing criterion of doctoral graduate research is a significant and original contribution to knowledge.

Once accepted, the candidate presents the thesis orally. This oral exam is open to the public.

Abstract

Hypertension is a significant public health concern in both adult and pediatric populations. With increasing prevalence of hypertension, there is growing emphasis on identifying risk factors for high blood pressure. Poor sleep has emerged as a significant predictor of hypertensive status. In particular, short sleep duration has been widely studied as a risk factor for cardiovascular disease, including hypertension. There is evidence that other dimensions of sleep, such as sleep disruption or timing, may influence blood pressure, but relatively few studies examine these associations. The objective of the present dissertation was to examine associations between blood pressure and specific sleep dimensions. Study 1 consisted of a scoping review of pediatric ambulatory blood pressure monitoring (ABPM) measurement practices and meta-analysis of circadian variation in pediatric blood pressure. Studies showed moderate fidelity to current measurement standards, but there was significant variability in data reporting. Youth showed pronounced circadian variation in blood pressure, supported by significant differences in day and night blood pressure. Study 2 was a meta-analysis examining associations between casual blood pressure (i.e., in-office recording) and the following sleep dimensions in children and adults: sleep duration, awakenings, sleep efficiency, sleep irregularity, and sleep stages. Higher blood pressure was associated with shorter sleep duration, more frequent awakenings, and poorer overall sleep. There was evidence of changes across age, with older samples showing stronger associations between blood pressure and sleep. Study 3 examined associations between casual blood pressure and objectively measured sleep dimensions (i.e., actigraphy, polysomnography) in a community sample of children. Higher blood pressure was significantly associated with shorter sleep duration, later bedtime, more frequent arousals (i.e., sleep disruption), and less time spent in restorative sleep stages. Overall, findings from this dissertation indicate that blood pressure is associated with multiple dimensions of sleep from early in the lifespan. Further research is needed to examine how these associations progress over time in order to develop effective prevention and interventions for hypertension.