Load-Dependent Arterial Stiffness Mechanisms are Responsible for Increased Large Artery Stiffness Observed among Women with a History of Preeclampsia

Abstract

Introduction: Preeclampsia is a pregnancy complication characterized by hypertension and multi-organ dysfunction and is a leading cause of maternal morbidity and mortality. Preeclampsia results in a two-four fold increased risk of developing hypertension and cardiovascular disease later in life. Large artery stiffness (LAS), a robust risk factor for hypertension and cardiovascular disease, and blood pressure (BP) are elevated after pregnancy in women with a history of preeclampsia (hxPE) and is associated with reduced cardiovagal baroreflex sensitivity (BRS). Whether elevated LAS in women with a hxPE is a consequence of structural remodeling of the arterial wall or the load applied to the arterial wall by the blood (i.e., BP) is unclear. Furthermore, it is unknown whether one or both LAS mechanisms are associated with differences in BRS. Therefore, we hypothesized that 1) structural- and load- dependent LAS would be elevated in women with a hxPE versus no hxPE postpartum controls, and 2) structural- and load- dependent LAS would be associated with BRS in women with hxPE.Methods: LAS was measured via carotid-femoral pulse wave velocity (aortic LAS), and carotid ultrasonography/tonometry (carotid LAS) among 115 women 1-5 years postpartum (age 34 ±4yrs; hxPE n=51; controls n=64). Participant-specific exponential models were used to standardize LAS measurements to a ‘reference’ BP (aortic: 90mmHg mean arterial pressure; carotid: BP 120/80mmHg) and used to calculate structural LAS. Load-dependent LAS was calculated as total minus structural LAS. Spontaneous cardiovagal BRS was measured using the sequence technique. Results: Systolic and diastolic BP were higher in women with hxPE compared with controls (all p<0.001). Aortic, but not carotid, LAS was 0.57 m/s higher in women with hxPE compared with controls (p=0.025). Load-dependent LAS was 0.39 m/s (aortic) and 0.5 m/s (carotid) higher in women with hxPE (p<0.001 for aortic and carotid), but no difference was observed for structural LAS measures (p>0.14 for both). Women with hxPE had 4.13 ms/mmHg lower BRS compared to controls (p=0.042). In women with hxPE, BRS was negatively associated with both aortic and carotid LAS (r=-0.37, p=0.042 and r=-0.38, p=0.025, respectively), and aortic load-dependent LAS (r=-0.39, p=0.033), after adjusting for age and body mass index. Conclusion: Load-dependent LAS mechanisms explained the higher aortic and carotid LAS observed among women with a hxPE and was associated with lower BRS. Our findings suggest that changes in BP and cardiovagal BRS may underpin in part the higher LAS observed in women with a hxPE. Grant funding: American Heart Association 22TPA969732 (to GLP) and 18SCG34350001 (to MKS). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.