BLO2D Unlimited

Strenuous exercise activates blood coagulation, mostly due to elevated platelet count, platelet hyperreactivity, increased thrombin generation and increased activity of several coagulation factors, especially factor 8 (FVIII) and von Willebrand factor (vWF). Mountaineering also appears to pose a risk for developing thrombosis. Healthy lowlanders moving to high altitude for a mean duration of 10 months were found to have a 30 times increased risk of developing a venous thromboembolism (VTE). Similarly, healthy soldiers stationed at high altitude were characterized by an almost 25-fold increased risk of developing deep calf vein thrombosis. Mountaineering usually involves repeated strenuous exercise, when walking, climbing, skiing or cycling. Because hypoxia and exercise both cause procoagulant changes, one might expect that exercise will amplify the altitude-induced hypercoagulability.


From 2 recent studies (Mont Blanc 1 and 2 studies), we concluded that hypoxia induces prothrombotic changes in blood. We have also found that strenuous exercise leads to prothrombotic changes (Red Meets Gold study), but these appear to be attenuated during repeated exercise (unpublished work). Mountaineering combines both hypoxia and repeated strenuous exercise.



In this study we aim to investigate the effect of 3x repeated strenuous exercise at high altitude on blood, using advanced techniques for studying thrombin generation, platelet function and fibrinolysis. It is hypothesized that high altitude and strenuous exercise cause increased thrombin generation, but that this effect will be attenuated during prolonged exposure and repeated exercise.

It is hypothesized that strenuous exercise at high altitude causes increased thrombin generation, but that this effect will be attenuated during prolonged exposure and repeated exercise.

N/A

- Strenuous physical exercise (heart rate reserve 60-85%) during 2 hours, once at sea level (baseline) and repeated 3x at high altitude (3,883 m above sea level)

- Venipuncture just before and immediately after exercise (8x27 ml)