Doing research at the top of the world
Apart from a spectacular view, what do researchers get out of lugging scientific equipment to Everest? It’s Everest Day, 60 years since Sir Edmund Hillary and Tenzing Norgay were the first to reach the summit, so here are Jules Griffin and Tom Ashmore from MRC Human Nutrition Research and the University of Cambridge to tell us about why they joined the recent Xtreme Everest 2 expedition, and the surreal nature of doing research in the world’s highest lab.
The aches in our legs have faded, the last of the headaches have receded and we are finally putting back on the weight we have lost during the trip. Now all that’s left to do is wait with bated breath for the samples from the expedition to arrive so our part in the scientific analysis can begin.
This Easter, along with 200 other volunteers, we took part in a trek from the airfield at Lukla in Nepal (at an elevation of 2,840m) to Everest Basecamp (5,364m) to examine how our bodies adapt to the low oxygen levels at high altitude. As part of this medical expedition we were tested at three laboratories at increasing elevations: Kathmandu (1,400m), Namche Bazaar (3,440m) and Everest Basecamp.
So why were we doing this? The science behind the expedition is centred on understanding why some patients do worse than others when admitted to intensive care. These patients often have hypoxia, low blood oxygen caused by the poor flow of blood around their bodies associated with the original illness or accident that put them in hospital. While we know that oxygen is vital for our bodies to function, we also know that people can adapt to the low oxygen levels at high altitudes so long as they get the chance to acclimatise. So the question is can we use these adaptations to treat people in intensive care?
The trek up to basecamp lasted 10 days and covered a distance 39 miles — a distance I have walked in a couple of days at sea level! However, it was the altitude that was the challenge. By the time we reached basecamp there was half the amount of oxygen we were used to. During the expedition our trek participants suffered from a variety of symptoms ranging from breathlessness, headaches — like a very bad hangover — insomnia and sleep apnoea. The sleep apnoea was one of the surprises. At basecamp we would wake gasping for air after our bodies had decided to stop breathing.
To assess our acclimatisation we underwent a variety of tests, including measurements of our heart rate, blood pressure, and blood flow. Researchers also took samples of our blood, muscle, urine and breath condensate. For the breath condensate we had to breathe for 10 minutes into a frozen tube — not nice if you get your nose caught on it! These samples were then tested to see how the low oxygen was affecting us and how we were adapting to it. We also undertook tests to look at whether the altitude may have caused genes to be turned on or off.
But the centrepiece of these activities was the exercise bike test. With heart rate monitors attached and a face mask to monitor our breathing rate, we completed a ramp and an endurance test at each of the laboratories. This was a surreal experience at Everest Basecamp, but a real privilege to take part in experiments at the highest laboratory in the world.
You might ask why this research can’t be done at sea level in a pressure chamber. For one thing, people probably wouldn’t have volunteered to live in a chamber for three and a half weeks, but there are cost and scientific reasons too. We wouldn’t have acclimatised in quite the same way, and experiments comparing chambers with the real Everest experience have had different results, suggesting that chambers can’t fully replace doing the trek.
Our scientific work will begin in the coming weeks as we use state-of-the-art analytical equipment to assess the samples of blood and muscle tissue which have been shipped back to Cambridge. While the scientific expedition is focused on understanding changes in intensive care patients, our own research is centred around understanding weight loss during the expedition. Everyone on the trek lost some weight, and understanding this process will help us figure out why some individuals lose weight when they have diseases such as cancer, or why some individuals cannot lose weight, as we see with obesity.
We hope our work will help us understand how we — and the other volunteers — adapted to high altitude and in turn give us clues about how to treat patients.
Jules Griffin and Tom Ashmore (4.5 and 9.5 kg lighter, respectively!)