Preeclampsia is not associated with elevated muscle sympathetic reactivity

Laura Marcela Reyes; Charlotte W Usselman; Rshmi Khurana; Radha S Chari; Michael K Stickland; Sandra T Davidge; Colleen G Julian; Craig D Steinback; Margie H Davenport

doi:10.1152/japplphysiol.00646.2020

Preeclampsia is not associated with elevated muscle sympathetic reactivity

J Appl Physiol (1985). 2021 Jan 1;130(1):139-148. doi: 10.1152/japplphysiol.00646.2020. Epub 2020 Nov 19.

Authors

Laura Marcela Reyes^{1

2}, Charlotte W Usselman¹, Rshmi Khurana^{2

3}, Radha S Chari^{4

3}, Michael K Stickland⁵, Sandra T Davidge^{4

3}, Colleen G Julian⁶, Craig D Steinback^{1

4}, Margie H Davenport^{1

4}

Affiliations

¹ Program for Pregnancy and Postpartum Health, Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, Alberta, Canada.
² Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
³ Department of Obstetrics and Gynecology, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada.
⁴ Women and Children's Health Research Institute (WCHRI), University of Alberta, Edmonton, Alberta, Canada.
⁵ Division of Pulmonary Medicine, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
⁶ Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado.

PMID: 33211599
DOI: 10.1152/japplphysiol.00646.2020

Abstract

To determine whether increased chemoreflex tonic activity is associated with augmented muscle sympathetic nervous system activity (MSNA) in women diagnosed with preeclampsia. Women with preeclampsia (n = 19; 32 ± 5 yr old, 31 ± 3 wk of gestation) were matched by age and gestational age with pregnant women (controls, n = 38, 32 ± 4 yr old, 31 ± 4 wk gestation; 2:1 ratio). MSNA (n = 9 preeclampsia) was assessed during baseline, peripheral chemoreflex deactivation (hyperoxia), and a cold pressor test (CPT). Baroreflex gain and diastolic blood pressure at which there is a 50% likelihood of MSNA occurring (T50) and plasma noradrenaline concentrations were measured. Baseline mean arterial pressure (MAP: 106 ± 11 vs. 87 ± 10 mmHg, P < 0.0001), noradrenaline concentrations (498 ± 152 pg/mL vs. 326 ± 147, P = 0.001), and T50 (79 ± 7 vs. 71 ± 9 mmHg, P = 0.02) were greater in women with preeclampsia than in controls. However, baseline MSNA (burst incidence [BI]: 41 ± 16 vs. 45 ± 13 bursts/100 hb, P = 0.4) was not different between groups. Responses to hyperoxia (ΔBI -5 ± 7 vs. -1 ± 8 bursts/100 hb, P = 0.1; ΔMAP -1 ± 3 vs. -2 ± 3 mmHg, P = 0.7) and CPT (ΔBI 15 ± 7 vs. 12 ± 11 bursts/100 hb, P = 0.6; ΔMAP 10 ± 4 vs. 12 ± 11 mmHg, P = 0.6) were not different between groups. Our findings question the assumption that increased MSNA contributes to hypertension in women with preeclampsia. The chemoreflex does not appear to contribute to an increase in MSNA in women with preeclampsia.NEW & NOTEWORTHY We wanted to determine whether increased chemoreflex tonic activity is associated with augmented muscle sympathetic nervous system activity (MSNA) in women diagnosed with preeclampsia. The chemoreflex does not contribute to increased MSNA in women with preeclampsia. Our data also challenge the belief that preeclampsia is associated with sympathetic neural hyperactivity. Thus, targeting sympathetic neural hyperactivity as therapeutic strategy is unlikely to be the most efficacious approach to treatment and management.

Keywords: muscle sympathetic nervous system activity; preeclampsia; pregnancy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Arterial Pressure
Baroreflex
Blood Pressure
Female
Heart Rate
Humans
Muscle, Skeletal
Pre-Eclampsia*
Pregnancy
Sympathetic Nervous System