Investigating the potential of a high altitude sleeping pill

UAA biology professor Chris Jung has been a climber all his life. He is also a trained sleep physiologist and chronobiologist.  What do these subjects all have in common? Apparently, melatonin.

"Melatonin is a hormone produced by the pineal gland in your brain," Jung, a doctorate in integrative physiology and neuroscience, explains. "It acts as a sedative and helps you sleep."

Melatonin is also a vasodilator (it causes your blood vessels to widen, thus decreasing blood pressure) and an antioxidant, according to Jung. So he put all these pieces together with his experience at high altitudes and asked the question: Could additional melatonin help climbers adapt to extreme altitude better? And if they adapt better, could that also help decrease the likelihood of cardiovascular and sleep problems and decrements in cognition at elevation?

This summer, for three and a half weeks in May and June, Jung took a team of researchers to Camp 14 on Denali to test his hypothesis. Camp 14 is named for its elevation of 14,200 feet. The Denali National Park Service rangers sent out emails to climbers ahead of time who planned to be on the mountain during the research team's window. In addition, a little bit of stormy weather helped them to recruit volunteers.

"I was very happy with how many people came to us to participate in the study," Jung says. "We ended up getting about 30 consents signed, and after everything was said and done we had 20 participants that we could use for the data."

Jung describes the field conditions, giving a big shout out to his climber-volunteers: "Even in a lab where everything is prearranged, you still get data missing from equipment failure, so you can imagine at subzero temperatures, we were at the mercy of batteries, which don't work as well when it's cold, and so on. And climbing is hard enough as it is-being in the cold; you're not sleeping as well at altitude-and then having this equipment on you when you're sleeping and have to hang out in a tent and have your blood pressure taken, it's just not the easiest of things. There were a lot of different hurdles to jump over, but it was really nice that we did get so many volunteers."

Jung says that this is the first time that melatonin has been tested in this extreme environment. At sea level, people do take melatonin as a sedative to help initiate sleep and it's also been used for cancer treatment and jet lag. So melatonin pills aren't new, but Jung's particular application is.

Jung's tests on Denali were set up as a double-blind, placebo-controlled study in which each participant received two pills-one night a melatonin pill and the other night a placebo. Nobody knew who got what pill which night, neither the volunteers nor the researchers. Post-pill, the researchers measured sleep variables (how well each participant slept each night, how fast they fell asleep, different stages of sleep, etc.) as well as cardiovascular variables (heart rate, blood oxygen saturation and blood pressure) and cognition.

"There is data that shows that people who spend long periods of time at extreme altitudes, for example on Everest or K2, show differences in their brain physiology before and after exposure to altitude," Jung explains. "And we know that this is because of oxidative stress. Between the already depleted oxygen supply at altitude and not sleeping well, it's a double whammy and has a dramatic effect on the neurology that's going on in the brain."

Although the team is still crunching numbers to measure outcomes, Jung is excited to see how this acute one-night test may lead to testing over a longer expedition, a higher expedition and dosage over multiple nights. His team's results will act as preliminary data for larger projects in the future.

In preparation for the "Sleep 2013" conference in Baltimore next summer, Jung expects to have his research abstract and results ready to publish by December. His research was made possible by a UAA Faculty Development Grant of $4,500 and a private grant that came through the UA Foundation for $700. Their sleep monitoring equipment was donated by Zeo Inc. and Jung collaborated with UAA's Department of Psychology to acquire the necessary cognitive tests to use, in this case, the Stroop Test. Mountain Hardware also helped the team out with a modest sponsorship.

Mostly, Jung is pleased by how well his research team worked together in the extreme conditions on Denali as well. Not only did they help kick in to cover expedition costs, they also split up tasks on the mountain for a smooth-running, professional operation.

In addition to the research expedition team (pictured right), UAA undergraduates Shea Lowery and Zach Worthington are helping Jung at sea level to process the data captured on the mountain. UAA's Loren Buck, Ph.D. (biology), and Yasuhiro Ozuru, Ph.D. (psychology) were collaborators on protocols, and Peter Hackett, M.D., from the University of Colorado School of Medicine and the Institute of Altitude Medicine was the project's medical monitor.

Keep an eye on Jung's CV for updates on the current melatonin research; results to be published in early 2013.