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Kristen Davis Dissertation_Final_FA2026_4.29.20261.22 MB
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Dissertation
Arterial stiffness, hemodynamic mechanisms and cognitive function in women with a history of preeclampsia: Implications for Home-Based Exercise
University of Iowa
Doctor of Philosophy (PhD), University of Iowa
Spring 2026
Abstract
Hypertensive disorders of pregnancy (HDP) are associated with increased cardiovascular disease (CVD) risk and reduced cognitive performance after delivery. Notably, part of the increased CVD risk postpartum has been attributed in part to vascular dysfunction, including large central artery stiffness, while the mechanisms contributing to reduced cognitive performance are less clear. Although central artery stiffness is observed in women with a history of HDP (hxHDP), such as preeclampsia, whether the observed arterial stiffening is driven by the influence of blood pressure extending on the arterial wall (i.e. load-dependent stiffness) or intrinsic changes to the extracellular matrix of the arterial wall (i.e. structural stiffness) remains unknown. In aging, increased central artery (aorta and carotid) stiffness and pulsatile pressure hemodynamics can negatively influence cognitive structure and function. However, whether the driving components of large central artery stiffness and pulsatile pressure hemodynamics in women with a history of preeclampsia (hxPE) mediate associations between preeclampsia status and cognitive function are unknown. Understanding the mechanisms driving CVD risk and cognitive performance impairments in women with a hxPE may identify targets for intervention. Non-pharmacological interventions may be key in young women with a hxHDP at subclinical CVD risk and demonstrating reduced cognitive performance, yet limited interventions exist for this population.This dissertation determined the mechanistic component contributing to higher aortic stiffness in women with a hxPE 1-5 years after delivery, using a novel participant-specific exponential modeling approach, and its association with cardiovagal baroreflex sensitivity, which aids in blood pressure regulation. It was determined that the load-dependent component of aortic stiffness was higher, and cardiovagal baroreflex sensitivity was lower, in women with a hxPE compared with women who have a history of normotensive pregnancies. Furthermore, load-dependent stiffness was negatively associated with cardiovagal baroreflex sensitivity in women with a hxPE. However, the cross-sectional nature of the study limits the ability to draw conclusions of causality or directionality regarding the associations between load-dependent stiffness and baroreflex sensitivity.
Similarly to aortic stiffness, components of carotid artery stiffness and pulsatile pressure hemodynamics, expressed as the amplitudes of the forward (Pf) and backward (Pb) traveling pressure waves away from and towards the heart, were determined and compared in women with a hxPE and with history of normotensive pregnancies. Additionally, we assessed differences in cognitive performance between the two groups using a battery of cognitive tests which were grouped into the domains of executive function and processing speed; two primary cognitive functions consistently demonstrated to be reduced in women with a hxPE. We observed higher carotid load-dependent stiffness, pulse pressure, Pb, and slower processing speed in women with a hxPE compared with those with a history of a normotensive pregnancy. To determine whether large central artery stiffness mediated the reduced cognitive performance in women with a hxPE, we conducted a mediation analysis between preeclampsia status and processing speed with carotid load-dependent stiffness, pulse pressure, and Pb as independent mediators. We determined that neither carotid load-dependent stiffness, pulse pressure, or Pb mediated the association between preeclampsia status and processing speed.
Finally, an 8-week moderate-vigorous home-based aerobic exercise program was delivered to 12 women with a hxHDP to determine its feasibility and preliminary efficacy to improve large central artery stiffness components, pulsatile pressure hemodynamics, and cognitive function (executive function and processing speed). The ramped program began with a weekly requirement of 60-90 total minutes in prescribed moderate-vigorous heart rate zones and progressed in weekly duration until participants completed 150+ minutes in the final two weeks of the intervention. Significant reductions in total and structural carotid artery stiffness and Pb were observed after the intervention. However, there were no significant changes in either executive function or processing speed domains.
Taken together, the elevated CVD risk in women with a hxPE is likely attributed in part to higher blood pressure, via load-dependent arterial stiffness, and elevated central pulsatile pressure hemodynamics, particularly Pb, compared with women with a history of normotensive pregnancy. Additionally, processing speed is significantly compromised in women with a hxPE. However, load-dependent stiffness and Pb do not mediate slower processing speed associated with preeclampsia status. Finally, aerobic exercise may be a feasible and effective interventional strategy to partly mitigate CVD risk in women with a hxHDP through reductions in total and structural carotid stiffness, and Pb. However, larger longitudinal randomized controlled studies are warranted to confirm these intervention findings and further evaluate the potential benefits of aerobic exercise on cognitive performance in women with a hxHDP.
Details
- Title: Subtitle
- Arterial stiffness, hemodynamic mechanisms and cognitive function in women with a history of preeclampsia: Implications for Home-Based Exercise
- Creators
- Kristen Davis
- Contributors
- Gary L Pierce (Advisor)Kara M Whitaker (Committee Member)Anna E Stanhewicz (Committee Member)Michelle W Voss (Committee Member)Donna A Santillan (Committee Member)
- Resource Type
- Dissertation
- Degree Awarded
- Doctor of Philosophy (PhD), University of Iowa
- Degree in
- Health and Human Physiology
- Date degree season
- Spring 2026
- Publisher
- University of Iowa
- Number of pages
- xii, 121 pages
- Copyright
- Copyright 2026 Kristen Davis
- Language
- English
- Date submitted
- 04/27/2026
- Description illustrations
- illustrations (some color)
- Description bibliographic
- Includes bibliographical references (page 98-111).
- Public Abstract (ETD)
Pregnancy disorders resulting in new onset high blood pressures (BP), called hypertensive disorders of pregnancy (HDP), and preeclampsia (PE) which is HDP accompanied by organ dysfunction, increase the risk for cardiovascular disease (CVD) and reduced cognitive performance after delivery. Mechanisms influencing increased CVD risk and reduced cognitive performance after a HDP and PE are not completely understood, with minimal therapy options for these consequences. This dissertation investigated differences in the elasticity and BP patterns of the large central arteries, which are CVD risk factors, between women with a history of PE (hxPE) and healthy pregnancy (HP), and whether these differences contribute to worse cognitive performance in this population. Finally, this study assessed how moderate-vigorous aerobic exercise affects arterial elasticity, BP patterns, and cognitive performance in women with a hxHDP.
Primary findings demonstrate that the mechanical load of BP on arterial walls drives reduced elasticity of the arteries, and BP waves being reflected back toward the heart are greater in women with a hxPE compared with a HP. Although women with a hxPE had slower processing speed, reduced elasticity from BP load and reflected pressure waves were not contributors to this association. Eight weeks of home-based aerobic exercise improved internal elasticity of the carotid artery and the reflected pressure wave, but not cognitive performance, in women with a hxHDP. Together, this dissertation identified mechanisms partly contributing to CVD risk and provides evidence that habitual aerobic exercise may be an effective therapy for CVD risk reduction in women with a hxHDP.
- Academic Unit
- Health, Sport, and Human Physiology
- Record Identifier
- 9985176870602771
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