Endothelin-1 Correlates with Blood Pressure and Pulse Pressure in Females with Lupus Associated Hypertension

Abstract

Systemic Lupus Erythematosus (SLE) is a common autoimmune disease that is classified by IgG complex deposition in end organs including the kidney, heart, and vasculature. SLE disproportionally affects women to men (9:1 ratio), with a high prevalence in African American women. Importantly, patients with an SLE diagnosis have common cardiovascular complications including hypertension. Importantly, numerous studies have reported that plasma and urinary endothelin-1 (ET-1) levels are elevated in patients with SLE or hypertension. However, few studies have investigated the role of the synergistic effects of SLE and hypertension on ET-1. Therefore, we hypothesized that women with SLE and hypertension would have elevated plasma ET-1 levels compared to SLE or hypertension alone. To investigate this, we recruited non-SLE non-HTN controls (n=8), non-SLE HTN (n=7), SLE non-HTN (n=5), and SLE-HTN (n=6) female human subjects and analyzed clinical and demographic characteristics, plasma ET-1, c-reactive protein (CRP), soluble vascular adhesion molecule-1 (sVCAM-1), and anti-Smith autoantibodies. We found that plasma ET-1 levels are significantly higher in African American compared to European American patients independent of SLE or blood pressure status (p=0.0182). When plasma ET-1 levels were correlated with age and body mass index (BMI), ET-1 had a positive association with age (r=0.4861;p=0.0118), but no correlation with BMI (r=0.2137;p=0.2945). When subjects we characterized by SLE diagnosis, we found that female subjects with SLE had elevated plasma ET-1 levels compared to non-SLE controls (p=0.0141). Next, we stratified subjects by blood pressure status and found that only SLE-HTN subjects had significantly elevated plasma ET-1 levels compared to non-SLE non-HTN controls (p=0.0005), and a trend for elevated ET-1 levels over SLE non-HTN (p=0.0799). Lastly, we correlated plasma ET-1 levels to offce systolic blood pressure, diastolic blood pressure and calculated pulse pressure. We found that plasma ET-1 positively associated with systolic blood pressure (r=0.5621;p=0.0035) and pulse pressure (r=0.5810;p=0.0023) but not diastolic blood pressure (r=0.3177;p=0.1217). These data demonstrate that plasma ET-1 levels associate with SLE diagnosis and blood pressure status in our cohort of female SLE human subjects. Further investigation of ET signaling should be done in SLE and SLE-HTN human subjects. Veterans Affairs Biomedical Laboratory Research & Development Career Development Award (CDA-2) 1IK2BX005605-01 to J.P.V.B, Medical University of South Carolina College of Medicine Program Project Grant to J.C.O and J.P.V.B., and Medical University of South Carolina Core Centers for Clinical Research Project Award P30AR072582 to M.A.C and J.P.V.B. 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.