Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function and endothelial activation

W. D. Toff, C. I. Jones, Isobel Ford, R. J. Pearse, H. G. Watson, Stephen James Watt, John A S Ross, D. P. Gradwell, A. J. Batchelor, K. R. Abrams, J. C. M. Meijers, A. H. Goodall, Michael Greaves

Research output: Contribution to journalArticle

98 Citations (Scopus)

Abstract

Context The link between long-haul air travel and venous thromboembolism is the subject of continuing debate. It remains unclear whether the reduced cabin pressure and oxygen tension in the airplane cabin create an increased risk compared with seated immobility at ground level.

Objective To determine whether hypobaric hypoxia, which may be encountered during air travel, activates hemostasis.

Design, Setting, and Participants A single-blind, crossover study, performed in a hypobaric chamber, to assess the effect of an 8- hour seated exposure to hypobaric hypoxia on hemostasis in 73 healthy volunteers, which was conducted in the United Kingdom from September 2003 to November 2005. Participants were screened for factor V Leiden G1691A and prothrombin G20210A mutation and were excluded if they tested positive. Blood was drawn before and after exposure to assess activation of hemostasis.

Interventions Individuals were exposed alternately ( >= 1 week apart) to hypobaric hypoxia, similar to the conditions of reduced cabin pressure during commercial air travel ( equivalent to atmospheric pressure at an altitude of 2438 m), and normobaric normoxia ( control condition; equivalent to atmospheric conditions at ground level, circa 70 m above sea level).

Main Outcome Measures Comparative changes in markers of coagulation activation, fibrinolysis, platelet activation, and endothelial cell activation.

Results Changes were observed in some hemostatic markers during the normobaric exposure, attributed to prolonged sitting and circadian variation. However, there were no significant differences between the changes in the hypobaric and the normobaric exposures. For example, the median difference in change between the hypobaric and normobaric exposure was 0 ng/mL for thrombin-antithrombin complex (95% CI, - 0.30 to 0.30 ng/mL); - 0.20 nmol/L for prothrombin fragment 1 + 2 ( 95% CI, - 0.03 to 0.01 nmol/L); 1.38 ng/mL for D-dimer ( 95% CI, - 3.63 to 9.72 ng/ mL); and - 2.00% for endogenous thrombin potential ( 95% CI, - 4.00% to 1.00%).

Conclusion Our findings do not support the hypothesis that hypobaric hypoxia, of the degree that might be encountered during long-haul air travel, is associated with prothrombotic alterations in the hemostatic system in healthy individuals at low risk of venous thromboembolism.

Original languageEnglish
Pages (from-to)2251-2261
Number of pages10
JournalJAMA
Volume295
Issue number19
DOIs
Publication statusPublished - May 2006

Keywords

  • flow-cytometric analysis
  • human-beings
  • plasma
  • blood

Cite this

Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function and endothelial activation. / Toff, W. D.; Jones, C. I.; Ford, Isobel; Pearse, R. J.; Watson, H. G.; Watt, Stephen James; Ross, John A S; Gradwell, D. P.; Batchelor, A. J.; Abrams, K. R.; Meijers, J. C. M.; Goodall, A. H.; Greaves, Michael.

In: JAMA, Vol. 295, No. 19, 05.2006, p. 2251-2261.

Research output: Contribution to journalArticle

Toff, WD, Jones, CI, Ford, I, Pearse, RJ, Watson, HG, Watt, SJ, Ross, JAS, Gradwell, DP, Batchelor, AJ, Abrams, KR, Meijers, JCM, Goodall, AH & Greaves, M 2006, 'Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function and endothelial activation', JAMA, vol. 295, no. 19, pp. 2251-2261. https://doi.org/10.1001/jama.295.19.2251
Toff, W. D. ; Jones, C. I. ; Ford, Isobel ; Pearse, R. J. ; Watson, H. G. ; Watt, Stephen James ; Ross, John A S ; Gradwell, D. P. ; Batchelor, A. J. ; Abrams, K. R. ; Meijers, J. C. M. ; Goodall, A. H. ; Greaves, Michael. / Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function and endothelial activation. In: JAMA. 2006 ; Vol. 295, No. 19. pp. 2251-2261.
@article{0bd65ef50ff64c18805ca1e761e741ab,
title = "Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function and endothelial activation",
abstract = "Context The link between long-haul air travel and venous thromboembolism is the subject of continuing debate. It remains unclear whether the reduced cabin pressure and oxygen tension in the airplane cabin create an increased risk compared with seated immobility at ground level.Objective To determine whether hypobaric hypoxia, which may be encountered during air travel, activates hemostasis.Design, Setting, and Participants A single-blind, crossover study, performed in a hypobaric chamber, to assess the effect of an 8- hour seated exposure to hypobaric hypoxia on hemostasis in 73 healthy volunteers, which was conducted in the United Kingdom from September 2003 to November 2005. Participants were screened for factor V Leiden G1691A and prothrombin G20210A mutation and were excluded if they tested positive. Blood was drawn before and after exposure to assess activation of hemostasis.Interventions Individuals were exposed alternately ( >= 1 week apart) to hypobaric hypoxia, similar to the conditions of reduced cabin pressure during commercial air travel ( equivalent to atmospheric pressure at an altitude of 2438 m), and normobaric normoxia ( control condition; equivalent to atmospheric conditions at ground level, circa 70 m above sea level).Main Outcome Measures Comparative changes in markers of coagulation activation, fibrinolysis, platelet activation, and endothelial cell activation.Results Changes were observed in some hemostatic markers during the normobaric exposure, attributed to prolonged sitting and circadian variation. However, there were no significant differences between the changes in the hypobaric and the normobaric exposures. For example, the median difference in change between the hypobaric and normobaric exposure was 0 ng/mL for thrombin-antithrombin complex (95{\%} CI, - 0.30 to 0.30 ng/mL); - 0.20 nmol/L for prothrombin fragment 1 + 2 ( 95{\%} CI, - 0.03 to 0.01 nmol/L); 1.38 ng/mL for D-dimer ( 95{\%} CI, - 3.63 to 9.72 ng/ mL); and - 2.00{\%} for endogenous thrombin potential ( 95{\%} CI, - 4.00{\%} to 1.00{\%}).Conclusion Our findings do not support the hypothesis that hypobaric hypoxia, of the degree that might be encountered during long-haul air travel, is associated with prothrombotic alterations in the hemostatic system in healthy individuals at low risk of venous thromboembolism.",
keywords = "flow-cytometric analysis, human-beings, plasma, blood",
author = "Toff, {W. D.} and Jones, {C. I.} and Isobel Ford and Pearse, {R. J.} and Watson, {H. G.} and Watt, {Stephen James} and Ross, {John A S} and Gradwell, {D. P.} and Batchelor, {A. J.} and Abrams, {K. R.} and Meijers, {J. C. M.} and Goodall, {A. H.} and Michael Greaves",
year = "2006",
month = "5",
doi = "10.1001/jama.295.19.2251",
language = "English",
volume = "295",
pages = "2251--2261",
journal = "JAMA",
issn = "0098-7484",
publisher = "American Medical Association",
number = "19",

}

TY - JOUR

T1 - Effect of hypobaric hypoxia, simulating conditions during long-haul air travel, on coagulation, fibrinolysis, platelet function and endothelial activation

AU - Toff, W. D.

AU - Jones, C. I.

AU - Ford, Isobel

AU - Pearse, R. J.

AU - Watson, H. G.

AU - Watt, Stephen James

AU - Ross, John A S

AU - Gradwell, D. P.

AU - Batchelor, A. J.

AU - Abrams, K. R.

AU - Meijers, J. C. M.

AU - Goodall, A. H.

AU - Greaves, Michael

PY - 2006/5

Y1 - 2006/5

N2 - Context The link between long-haul air travel and venous thromboembolism is the subject of continuing debate. It remains unclear whether the reduced cabin pressure and oxygen tension in the airplane cabin create an increased risk compared with seated immobility at ground level.Objective To determine whether hypobaric hypoxia, which may be encountered during air travel, activates hemostasis.Design, Setting, and Participants A single-blind, crossover study, performed in a hypobaric chamber, to assess the effect of an 8- hour seated exposure to hypobaric hypoxia on hemostasis in 73 healthy volunteers, which was conducted in the United Kingdom from September 2003 to November 2005. Participants were screened for factor V Leiden G1691A and prothrombin G20210A mutation and were excluded if they tested positive. Blood was drawn before and after exposure to assess activation of hemostasis.Interventions Individuals were exposed alternately ( >= 1 week apart) to hypobaric hypoxia, similar to the conditions of reduced cabin pressure during commercial air travel ( equivalent to atmospheric pressure at an altitude of 2438 m), and normobaric normoxia ( control condition; equivalent to atmospheric conditions at ground level, circa 70 m above sea level).Main Outcome Measures Comparative changes in markers of coagulation activation, fibrinolysis, platelet activation, and endothelial cell activation.Results Changes were observed in some hemostatic markers during the normobaric exposure, attributed to prolonged sitting and circadian variation. However, there were no significant differences between the changes in the hypobaric and the normobaric exposures. For example, the median difference in change between the hypobaric and normobaric exposure was 0 ng/mL for thrombin-antithrombin complex (95% CI, - 0.30 to 0.30 ng/mL); - 0.20 nmol/L for prothrombin fragment 1 + 2 ( 95% CI, - 0.03 to 0.01 nmol/L); 1.38 ng/mL for D-dimer ( 95% CI, - 3.63 to 9.72 ng/ mL); and - 2.00% for endogenous thrombin potential ( 95% CI, - 4.00% to 1.00%).Conclusion Our findings do not support the hypothesis that hypobaric hypoxia, of the degree that might be encountered during long-haul air travel, is associated with prothrombotic alterations in the hemostatic system in healthy individuals at low risk of venous thromboembolism.

AB - Context The link between long-haul air travel and venous thromboembolism is the subject of continuing debate. It remains unclear whether the reduced cabin pressure and oxygen tension in the airplane cabin create an increased risk compared with seated immobility at ground level.Objective To determine whether hypobaric hypoxia, which may be encountered during air travel, activates hemostasis.Design, Setting, and Participants A single-blind, crossover study, performed in a hypobaric chamber, to assess the effect of an 8- hour seated exposure to hypobaric hypoxia on hemostasis in 73 healthy volunteers, which was conducted in the United Kingdom from September 2003 to November 2005. Participants were screened for factor V Leiden G1691A and prothrombin G20210A mutation and were excluded if they tested positive. Blood was drawn before and after exposure to assess activation of hemostasis.Interventions Individuals were exposed alternately ( >= 1 week apart) to hypobaric hypoxia, similar to the conditions of reduced cabin pressure during commercial air travel ( equivalent to atmospheric pressure at an altitude of 2438 m), and normobaric normoxia ( control condition; equivalent to atmospheric conditions at ground level, circa 70 m above sea level).Main Outcome Measures Comparative changes in markers of coagulation activation, fibrinolysis, platelet activation, and endothelial cell activation.Results Changes were observed in some hemostatic markers during the normobaric exposure, attributed to prolonged sitting and circadian variation. However, there were no significant differences between the changes in the hypobaric and the normobaric exposures. For example, the median difference in change between the hypobaric and normobaric exposure was 0 ng/mL for thrombin-antithrombin complex (95% CI, - 0.30 to 0.30 ng/mL); - 0.20 nmol/L for prothrombin fragment 1 + 2 ( 95% CI, - 0.03 to 0.01 nmol/L); 1.38 ng/mL for D-dimer ( 95% CI, - 3.63 to 9.72 ng/ mL); and - 2.00% for endogenous thrombin potential ( 95% CI, - 4.00% to 1.00%).Conclusion Our findings do not support the hypothesis that hypobaric hypoxia, of the degree that might be encountered during long-haul air travel, is associated with prothrombotic alterations in the hemostatic system in healthy individuals at low risk of venous thromboembolism.

KW - flow-cytometric analysis

KW - human-beings

KW - plasma

KW - blood

U2 - 10.1001/jama.295.19.2251

DO - 10.1001/jama.295.19.2251

M3 - Article

VL - 295

SP - 2251

EP - 2261

JO - JAMA

JF - JAMA

SN - 0098-7484

IS - 19

ER -