Very interesting! I grew up at what amounts to "altitude" for many at 6,400 feet. Altitude of 14,000+ feet was under an hour by car and most summer weekends the family would go to Rocky Mountain National Park or such. The air is clean, a surprising amount of ozone and let's face it, tundra above tree-line is beautiful beyond art.
I'm not sure what tangible benefits are gained by sleeping at altitude, which is just less oxygen in a tent. In fact I had an oxygen tent for the times I needed extra support during an infection or such. The only thing I can think of is my heart pounding all night camping at 13,000 feet and higher. Lots of star gazing from my sleeping bag and little sleep isn't my idea of improving my health.
My own curiosity about helping me be healthier while sleeping is a hyperbaric chamber, in effect being pressurized to a depth below sea level with the weight of so much water causing gasses to dissolve in the blood and tissues. Assuming I could increase the oxygen to something near 100%, having this vital gas in concentration throughout the body tissues just might discourage anaerobic bugs from growing and maybe even killing certain pathogens. Oxygen in concentration not typically found in a healthy body changes the pH, which again might discourage bacterial growth, might help in high concentrations, or possibly the low concentration at altitude.
Something tells me that studies have been done for both extremes. A little bit of researching literature studying O2 concentrations might be a good first step.
LL
