Abstract
Elevated Resting Blood Pressure (ERBP) in the prehypertensive range is associated with increased risk of hypertension and cardiovascular disease, the mechanisms of which remain unclear. Prior studies have suggested that ERBP may be associated with overactivation and dysregulation of the sympathetic nervous system (SNS). We hypothesized that compared to normotensives (≤120/80 mmHg), ERBP (120/80-139/89 mmHg) has higher SNS activity, impaired arterial baroreflex sensitivity (BRS), and increased vascular inflammation. Twenty-nine participants were studied: 16 otherwise healthy individuals with ERBP (blood pressure (BP) 130 ± 2/85 ± 2 mmHg) and 13 matched normotensive controls (mean BP 114 ± 2/73 ± 2 mmHg). We measured muscle sympathetic nerve activity (MSNA), beat-to-beat BP, and continuous electrocardiogram at rest and during arterial BRS testing via the modified Oxford technique. Blood was analyzed for the following biomarkers of vascular inflammation: Lipoprotein-associated phospholipase A2 (Lp-PLA2), E-selectin, and intercellular adhesion molecule 1 (ICAM-1). Resting MSNA burst frequency (22 ± 2 vs. 16 ± 2 bursts/min, P = 0.036) and burst incidence (36 ± 3 vs. 25 ± 3 bursts/100 heart beats, P = 0.025) were higher in ERBP compared to controls. Cardiovagal BRS was blunted in ERBP compared to controls (13 ± 2 vs. 20 ± 3 msec/mmHg, P = 0.032), while there was no difference in sympathetic BRS between groups. Lp-PLA2 (169 ± 8 vs. 142 ± 9 nmol/min/mL, P = 0.020) and E-selectin (6.89 ± 0.6 vs. 4.45 ± 0.51 ng/mL, P = 0.004) were higher in ERBP versus controls. E-selectin (r = 0.501, P = 0.011) and ICAM-1 (r = 0.481, P = 0.015) were positively correlated with MSNA, while E-selectin was negatively correlated with cardiovagal BRS (r = ±0.427, P = 0.030). These findings demonstrate that individuals with ERBP have SNS overactivity and impaired arterial BRS that are linked to biomarkers of vascular inflammation.
| Original language | English (US) |
|---|---|
| Article number | e14057 |
| Journal | Physiological Reports |
| Volume | 7 |
| Issue number | 7 |
| DOIs | |
| State | Published - Apr 2019 |
| Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by Merit Review Award number I01CX001065 (to J. Park) from the United States (U.S.) Department of Veterans Affairs Clinical Sciences Research and Development Program; National Heart Lung Blood Institute R01 HL135183; American Heart Association National Affiliate, Collaborative Sciences Award 15CSA24340001; National Institutes of Health training grant T32 DK-00756; resources and the use of facilities at the Clinical Studies Center of the Atlanta VA Healthcare System; Department of Veterans Affairs, Veterans Health Administration, Office of Research and Development and the Clinical Studies Center, Decatur, Georgia; the Atlanta Research and Education Foundation.
Publisher Copyright:
© 2019 The Authors.
Keywords
- Baroreflex
- Blood pressure
- Inflammation
- MSNA
