The Role of the Autonomic Nervous System in the Regulation of Aortic Stiffness.
The autonomic nervous system is important in regulating blood pressure, but whether it regulates aortic stiffness is more contentious. We conducted 3 studies in young, healthy individuals to address this important question. Study 1 was a cross-sectional study of 347 subjects with detailed measurements of hemodynamics and heart rate variability. In study 2, 9 subjects were given a bolus of intravenous nicotinic ganglion blocker, pentolinium, or saline in a random order and hemodynamics and heart rate variability were assessed before and after. In study 3, changes in hemodynamics and heart rate variability were assessed during stimulation of the sympathetic nervous system with the use of isometric handgrip exercise in 12 subjects. Study 1: aortic pulse wave velocity (P=0.003) was lowest in the subjects with the highest parasympathetic activity, but after adjusting for mean arterial pressure, the effect was abolished (P=0.3). Study 2: after pentolinium, sympathetic and parasympathetic activity fell (P=0.001 for both), mean arterial pressure, and heart rate increased (P=0.004 and P=0.04, respectively), but there was no change in pulse wave velocity in comparison to placebo (P=0.1). Study 3: during handgrip exercise, sympathetic activity (P=0.003), mean arterial pressure (P<0.0001), and aortic pulse wave velocity increased (P=0.013). However, pulse wave velocity adjusted for mean arterial pressure did not change (P=0.1). The main finding of these studies is that in young healthy subjects, the autonomic nervous system does not have a pressure-independent role in the regulation of aortic stiffness. However, these findings may not apply to patients with increased sympathetic tone or hypertension.
From the Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, United Kingdom. km391@medschl.cam.ac.uk.
Kaisa M
KM
Mäki-Petäjä
From the Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, United Kingdom.
Sharon M L
SM
Barrett
From the Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, United Kingdom.
Sarah V
SV
Evans
From the Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, United Kingdom.
Joseph
J
Cheriyan
From the Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, United Kingdom.
Carmel M
CM
McEniery
From the Division of Experimental Medicine and Immunotherapeutics, University of Cambridge, United Kingdom.
Ian B
IB
Wilkinson
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D055815:Young Adult; D062186:Arterial Pressure / Q000502:physiology; D001341:Autonomic Nervous System / Q000503:physiopathology; D018592:Cross-Over Studies; D003430:Cross-Sectional Studies; D004311:Double-Blind Method; D018737:Hand Strength / Q000502:physiology; D064368:Healthy Volunteers; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology; D006973:Hypertension / Q000503:physiopathology; D010425:Pentolinium Tartrate / Q000008:administration & dosage; D011379:Prognosis; D063177:Pulse Wave Analysis; D012380:Role; D059289:Vascular Stiffness / Q000187:drug effects / Q000502:physiology
D010425:Pentolinium Tartrate
aortic stiffness; autonomic nervous system; blood pressure; healthy volunteers; heart rate; hemodynamics
J Hypertens. 1998 Dec;16(12 Pt 2):2079-84
9886900
Clin Cardiol. 1999 Mar;22(3):207-12
10084063
Eur Heart J. 1993 Feb;14(2):160-7
8449191
J Physiol. 1974 Jul;240(1):111-24
4850798
J Appl Physiol (1985). 1995 Nov;79(5):1546-55
8594012
Hypertens Res. 2004 Dec;27(12):925-31
15894832
J Am Coll Cardiol. 2014 Feb 25;63(7):636-46
24239664
J Hypertens. 2010 May;28(5):979-84
20408258
J Exp Biol. 1999 Dec;202(Pt 23):3305-13
10562513
J Hypertens. 1988 Sep;6(9):711-7
3183374
Clin Auton Res. 2004 Dec;14(6):369-75
15666064
J Appl Physiol (1985). 1994 Jun;76(6):2832-9
7928918
J Cardiovasc Pharmacol. 2007 Nov;50(5):487-96
18030057
J Hypertens. 1999 Aug;17(8):1117-23
10466467
Am J Physiol. 1994 Oct;267(4 Pt 2):H1368-76
7943382
Mayo Clin Proc. 2009 Sep;84(9):822-30
19720780
Z Biol. 1963 Oct;114:89-111
14153231
Clin Sci (Lond). 1980 Dec;59 Suppl 6:279s-282s
7449271
J Am Coll Cardiol. 2010 Mar 30;55(13):1318-27
20338492
Br J Anaesth. 1981 Nov;53(11):1151-4
7326161
Circulation. 1971 Sep;44(3):413-8
5097443
Circulation. 1998 May 26;97(20):2037-42
9610534
Am J Physiol. 1990 Mar;258(3 Pt 2):H713-21
2316686
Eur Heart J. 1984 Aug;5(8):609-16
6434312
J Physiol. 2005 Oct 1;568(Pt 1):315-21
16037092
Hypertension. 2005 Jul;46(1):221-6
15867140
Am J Physiol. 1969 Dec;217(6):1644-51
5353039
Diabetes Care. 2013 Aug;36(8):2351-8
23435158
Blood Press Monit. 1996 Feb;1(1):55-61
10226203
Clin Hypertens. 2015 Apr 23;21:5
26893918
Acta Physiol Scand. 1997 Feb;159(2):139-45
9055941
Clin Nephrol. 2014 Jan;81(1):9-19
24356038