But really, why would one go through all this baseline testing, fly to the other side of the world, trek up to 5,000 m and repeat all the tests over again (I'll get to these crazy tests in a bit).
Well, I think the first real reason is that we're science geeks. Figuring out how the body works is something that we're all excited about. Figuring it out in "extreme" scenarios is even cooler.
The second reason is that going to the research pyramid at 5,050 m for 3 weeks allows us to do things we can't do in our labs. Sure, Phil has an environmental chamber that allows us to make the oxygen level the same as what we'd see at the Pyramid, but who wants to live in Phil's lab for 3 weeks (to add some perspective to this- there is no bathroom in his environmental chamber, and you'd have to spend 3 weeks with Phil. Wait, aren't we doing that?). So, using the environmental chamber allows us to look at acute adjustments in physiologic systems to reduced oxygen levels, but we can't study the adaptation or acclimatization. At the Pyramid we can study both the acute and chronic adaptation to reduced oxygen level. In addition, we will be able to do some of the studies on high altitude natives who have been living there for generations.
As our group of researchers is diverse in their backgrounds and expertise, and given that we will be at the Pyramid for 3 weeks, the research projects that we are undertaking are numerous, but fall under the following major themes (underneath are the "smaller" purposes of the projects):
CEREBROVASCULAR (Brain & Blood Vessels)
- To assess the relationship between ventilatory and regional cerebrovascular sensitivity to CO2 in sea level residents upon arrival to and following partial acclimatization to high altitude, and high altitude natives.
- To measure regional distribution of brain blood flow (CBF) and regional brain metabolism at both rest and exercise at sea level, during acute hypoxia and following ascent to high altitude.
- To assess the relative role of pulmonary arterial hypertension on intrapulmonary arteriovenous shunt during acute hypoxia and following ascent to high altitude.
- To study the effect of increased pulmonary arterial pressure on right heart and cerebral venous outflow pressures, and the resultant changes to CBF regulation at high altitude.
- To evaluate peripheral cardiovascular and cardiac (dys)function and remodeling during acclimatization to high altitude in sea-level residents and high altitude natives.
- To assess neurocognitive function and brain morphology before, during and after ascent to high altitude
- To elucidate the role of acid-base balance and CBF in the etiology of central sleep apnea in healthy humans at high altitude.
- To test whether AMS is caused by disregulation of ‘normal’ physiological responses to altitude; namely, (i) inappropriate neuro-endocrine-mediated retention of body water, (ii) hypoxia-induced disruption in CBF regulation
I know this is a lot to take in, but we're doing a tonne of stuff! I'll try to do a post or two on each of these sections (including a glossary for my Mom) as we go along. Or even better, I'll get the other researchers on the expedition to write a paragraph each on their involvement and contribution (Trev, Glen, you're up first!).