TY - JOUR

T1 - Body height and arterial pressure in seated and supine young males during +2 G centrifugation

AU - Arvedsen, Sine K.

AU - Eiken, Ola

AU - Kölegård, Roger

AU - Petersen, Lonnie G.

AU - Norsk, Peter

AU - Damgaard, Morten

N1 - Copyright © 2014, American Journal of Physiology - Regulatory, Integrative and Comparative Physiology.

PY - 2015/11/1

Y1 - 2015/11/1

N2 - It is known that arterial pressure correlates positively with body height in males and it has been suggested that this is due to the increasing vertical hydrostatic gradient from the heart to the carotid baroreceptors. Therefore we tested the hypothesis that a higher gravitoinertial stress induced by the use of a human centrifuge would increase mean arterial pressure (MAP) more in tall than in short males in the seated position. In short (162-171cm, n=8) and tall (194-203cm, n=10) healthy males (18-41yr), brachial arterial pressure, heart rate (HR) and cardiac output were measured during +2G centrifugation, while they were seated upright with the legs kept horizontal (+2Gz). In a separate experiment, the same measurements were done with the subjects supine (+2Gx). During +2Gz MAP increased in the short (22±2 mmHg, P <0.0001) and tall (23±2 mmHg, P <0.0001) males, with no significant difference between the groups. HR increased more (P <0.05) in the tall than in the short group (14±2 versus 7±2 bpm). Stroke volume (SV) decreased in the short group (26±4 mL, P =0.001) and more so in the tall group (39±5 mL, P <0.0001; short vs tall P =0.047). During +2GX, systolic arterial pressure increased (P <0.001) and SV (P =0.012) decreased in the tall group only. In conclusion, during +2Gz MAP increased in both short and tall males with no difference between the groups. However, in the tall group HR increased more during +2Gz which could be caused by a larger hydrostatic pressure gradient from heart to head leading to greater inhibition of the carotid baroreceptors.

AB - It is known that arterial pressure correlates positively with body height in males and it has been suggested that this is due to the increasing vertical hydrostatic gradient from the heart to the carotid baroreceptors. Therefore we tested the hypothesis that a higher gravitoinertial stress induced by the use of a human centrifuge would increase mean arterial pressure (MAP) more in tall than in short males in the seated position. In short (162-171cm, n=8) and tall (194-203cm, n=10) healthy males (18-41yr), brachial arterial pressure, heart rate (HR) and cardiac output were measured during +2G centrifugation, while they were seated upright with the legs kept horizontal (+2Gz). In a separate experiment, the same measurements were done with the subjects supine (+2Gx). During +2Gz MAP increased in the short (22±2 mmHg, P <0.0001) and tall (23±2 mmHg, P <0.0001) males, with no significant difference between the groups. HR increased more (P <0.05) in the tall than in the short group (14±2 versus 7±2 bpm). Stroke volume (SV) decreased in the short group (26±4 mL, P =0.001) and more so in the tall group (39±5 mL, P <0.0001; short vs tall P =0.047). During +2GX, systolic arterial pressure increased (P <0.001) and SV (P =0.012) decreased in the tall group only. In conclusion, during +2Gz MAP increased in both short and tall males with no difference between the groups. However, in the tall group HR increased more during +2Gz which could be caused by a larger hydrostatic pressure gradient from heart to head leading to greater inhibition of the carotid baroreceptors.

U2 - 10.1152/ajpregu.00524.2014

DO - 10.1152/ajpregu.00524.2014

M3 - Journal article

C2 - 26290109

VL - 309

SP - R1172-R1177

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6119

IS - 9

ER -