Dr. Charles Czeisler, MD, PhD, is up to some incredible things. He and his colleagues at Brigham and Women’s Hospital recently received NASA’s Johnson Space Center Director’s Innovation Award in Houston for their work on light systems, which will help astronauts adjust their Circadian clocks. He’s also presenting at this year’s Partners HealthCare World Medical Innovation Forum, on April 27 – 29, 2015.
As the chief of the Division of Sleep and Circadian Disorders in the Departments of Medicine and Neurology at the Brigham and Women’s Hospital, the Baldino Professor of Sleep Medicine and the director of the Division of Sleep Medicine at Harvard Medical School, Czeisler has several decades of experience researching sleep medicine and Circadian rhythms. This week, we sat down with him to talk about his research, the future of sleep medicine and his plans for the World Medical Innovation Forum.
Q: What led you to specialize in sleep medicine?
So my area within sleep medicine has to do with Circadian rhythms – the regulation of alertness and performance, the resetting of the biological clock by light, the properties of circadian rhythms to control sleeping and waking, our resetting capacity, and so on. I began my research career looking at hormones, and many of those hormones are robustly regulated by this internal clock. That got me interested in how our internal clock controls sleeping and waking. Then I saw that the timing of sleep itself has huge impact on the release of hormones, and that fascinated me.
It became clear that many hormones are regulated by the interaction between the timing of sleep and the circadian clock. Trying to understand that, I began to study the causes of defective timing of the Circadian clock. The clock has a number of properties, one of which is the period of its oscillation, and since the period of the Circadian clock is not exactly 24 hours, it has to reset each day. What are the factors in resetting it? Humans are different in that our interactions with each other and other environmental factors control our clock more than all other species, although light is still the most powerful regulator of our Circadian clock.
Q: You and your colleagues have done a lot of work with NASA. What led you to work there and why do you enjoy studying sleep medicine for astronauts?
I began working with NASA 25 years ago. It had just been discovered that light influences sleep patterns – in fact, we had published a series of papers about that, one of which said that properly timed exposure to light and darkness could facilitate adaptation to night shift work. And at that time, the space shuttle program needed to initiate some night launches, but a great deal of crew members were having difficulty working at night and trying to sleep during the daytime, which is common for most night shift workers. So we published a paper in 1990 showing that you could reset circadian rhythms so that workers would be as alert during the night as they normally would be during the day.
One day, I got a call asking me to come to Houston, asking if I thought I could do that for the astronauts. I worked with NASA to get the proper lights installed in the space station, which will be done in October of next year. The lights will allow crew members to get exposure to shorter wavelengths of light in the morning, which is required to reset their Circadian system to an earlier hour, and longer wavelengths of light in the evening, which should have less of an adverse effect on their ability to sleep. We actually just published a paper saying that exposure to shorter wavelengths of light from handhelds like the iPad and eReaders adversely affect our ability to sleep. Anyway, it was the design of that lighting system that got us the Johnson Space Center Director’s Innovation Award.
Q: You’re going to be speaking at the World Medical Innovation Forum. In your opinion, what are some of the most innovative ideas coming out of sleep medicine? What will you discuss at the forum?
There are many new exciting things, one of which is the recognition that during sleep, a critical brain function occurs. Since the brain doesn’t have a lymph system to clear toxic debris, it has to perform this function during sleep. During sleep, the cells in the brain actually shrink so that the newly described lymphatic channels can more easily remove this debris. One of the toxic build-ups is M1 beta-amyloid, which is associated with Alzheimer’s and dementia, and is removed at two to three times the rate during sleep.
Q: Last question – we write about wearables quite often and we’ve recently seen an influx of sleep tracking devices entering the market. What kind of an impact, if any, could these devices make on sleep health?
I think these are potentially useful. When we recorded 8,200 nights of sleep on the ground and in space, we were using technology like that. So we’ve been using activity monitors to record the timing of sleeping and making for three decades, but the instruments used to be $2,500 a piece, and we needed technicians to operate them. Accessibility to the general consumer is great. However, I haven’t seen a lot of validation work done, and I think that needs to be done before they’re marketed to the public.
Brendan Pease was MedTech Boston's first ever editorial and events intern. He is now a junior at Harvard University where he studies Molecular and Cellular Biology. He’s also the Co-Editor-in-Chief for the Harvard Science Review. Previously, he worked as a Market Intelligence intern at athenahealth and as a research assistant in the Goldberg Laboratory at Massachusetts General Hospital.
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