DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Abstract P192: Orthostatic Tolerance Before And After 60 Days Of Strict Head Down Tilt Bedrest With And Without Daily Artificial Gravity Training

Hönemann, Jan and Hoffmann, F. and Möstl, S. and Heusser, K. and Mulder, E. and van Herwaarden, T. and Lee, S. and Jordan, J and Tank, Jens (2021) Abstract P192: Orthostatic Tolerance Before And After 60 Days Of Strict Head Down Tilt Bedrest With And Without Daily Artificial Gravity Training. Hypertension. American Heart Association, Inc.. doi: 10.1161/hyp.78.suppl_1.P192. ISSN 0194-911X.

Full text not available from this repository.

Official URL: https://www.ahajournals.org/doi/10.1161/hyp.78.suppl_1.P192


Background: Orthostatic intolerance occurs after space flight, immobilization and in patients with autonomic diseases, so there is a need for more effective countermeasures. We hypothesized that daily artificial gravity elicited through short-arm centrifugation attenuates plasma volume loss and orthostatic intolerance following 60 days of HDTBR, which models cardiovascular responses to weightlessness. Methods: We studied 24 healthy persons (8 women, 33.4±9.3 yr, 24.3±2.1 kg/m2) exposed to 60d HDTBR. Subjects were assigned to 30 min/d continuous short arm centrifugation (cAG), 6x5 min short arm centrifugation (iAG), or a control group (ctr, no countermeasures). Head-up tilt testing (15 min of 80°) followed by incremental lower body negative pressure (-10 mmHg every 3 min) until presyncope was performed before and at the end of HDTBR. Plasma volume was measured (CO rebreathing) 12-2 days before and after 56d of HDTBR. Stroke volume was measured by cMRI. Norepinephrine, epinephrine, aldosterone, and renine plasma levels were measured before and after HDTBR. Results: Time to presyncope decreased in all groups following bedrest (ctr: 22:56 min pre and 9:35 min post, cAG 15:34 min pre and 10:11 min post; iAG 14:56 min pre and 10:00 min post, p<0.001). The significant interaction (p=0.025) between bedrest and intervention was explained by greater baseline orthostatic tolerance time in the ctr. AG Data was pooled analysis. The reduction in stroke volume (ctr, pre: 93±19 ml, HDTBR: 69±13 ml, AG, pre: 88±20 ml, HDTBR: 67±17 ml) and plasma volume was similar (ctr, pre: 4155±1085 ml, HDTBR: 3855±1087 ml, AG, pre: 4114±1250 ml, HDTBR: 3674± 1313 ml). Catechols and aldosterone did not change significantly during bedrest. The increase in renine was similar between groups (ctr pre: 18±12 mE/L, HDTBR: 21±8 mE/L, AG pre: 21±10 mE/L, HDTBR: 31±12 mE/L). Conclusions: 30 min daily AG didn’t prevent a reduction in orthostatic tolerance following 60d HDTBR. Whether numerically smaller reductions in orthostatic tolerance in the AG groups indicate efficacy or result from baseline differences can’t be ascertained. A stronger AG stimulus or combination with other countermeasures might be required to maintain orthostatic tolerance and to attenuate the volume reduction.

Item URL in elib:https://elib.dlr.de/186771/
Document Type:Article
Title:Abstract P192: Orthostatic Tolerance Before And After 60 Days Of Strict Head Down Tilt Bedrest With And Without Daily Artificial Gravity Training
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Hönemann, JanUniv of Cologne and German Aerospace Cntr, Institute of Aerospace Medicine, Cologne, GermanyUNSPECIFIEDUNSPECIFIED
Hoffmann, F.Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.;Department of Cardiology, Pneumology, and Angiology, Heart Center of the University of Cologne, GermanyUNSPECIFIEDUNSPECIFIED
Möstl, S.Institute of Aerospace Medicine, German Aerospace Center (DLR), Cologne, Germany.UNSPECIFIEDUNSPECIFIED
Heusser, K.UNSPECIFIEDhttps://orcid.org/0000-0002-2571-5585UNSPECIFIED
Mulder, E.German Aerospace Center (DLR), Institute of Aerospace Medicine, Space Physiology, Cologne, GermanyUNSPECIFIEDUNSPECIFIED
van Herwaarden, T.Radboud Universitair Medisch Centrum, Nijmegen, NetherlandsUNSPECIFIEDUNSPECIFIED
Lee, S.KBR, Inc., Cardiovascular and Vision Laboratory, NASA Human Health and Performance Directorate, Houston, TXUNSPECIFIEDUNSPECIFIED
Jordan, JUNSPECIFIEDhttps://orcid.org/0000-0003-4518-0706UNSPECIFIED
Tank, JensUNSPECIFIEDhttps://orcid.org/0000-0002-5672-1187UNSPECIFIED
Date:27 August 2021
Journal or Publication Title:Hypertension
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In ISI Web of Science:Yes
Publisher:American Heart Association, Inc.
Keywords:Orthostatic Tolerance; Head Down Tilt Bedrest; Gravity training
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Research under Space Conditions
DLR - Research area:Raumfahrt
DLR - Program:R FR - Research under Space Conditions
DLR - Research theme (Project):R - CardioBrain
Location: Köln-Porz
Institutes and Institutions:Institute of Aerospace Medicine
Institute of Aerospace Medicine > Cardiovascular Medicine in Aerospace
Institute of Aerospace Medicine > Muscle and Bone Metabolism
Deposited By: Schrage, Larissa
Deposited On:30 Jun 2022 13:58
Last Modified:30 Jun 2022 13:58

Repository Staff Only: item control page

Help & Contact
electronic library is running on EPrints 3.3.12
Website and database design: Copyright © German Aerospace Center (DLR). All rights reserved.