Episode 226: Optimizing Sleep

Introduction Dr. Arreaza: Hello, everyone, today we continue with our series about sleep. I invite you to listen to Moira Wilson on Episodes 220 and 221 about the approach of insomnia and CBT-I in adults. Today we will discuss not only what to do, but also why it works. We frequently hear advice like ‘get more sleep,’ but we need to dig deeper into the physiology behind it. So, Dr. Kim and Dr. Carlisle are here to briefly explain the physiology of sleep and what we can do to support better sleep. But before we start, let’s welcome Dr. Carlisle, who recently matched to our program. He will start his residency soon, and Dr. Kim, who will soon become a PGY2, welcome doctors.  Dr. Carlisle: [Introduce yourself].  Dr. Kim: [Introduce yourself].  Dr. Arreaza: Let’s start simple. Why does sleep matter clinically? Why Sleep Matters Dr. Kim: Sleep is one of the most important biological processes we have. It’s not passive; it’s highly active and tightly regulated. It affects cognition, metabolism, immune function, cardiovascular health, and hormonal balance. When sleep is disrupted, you see downstream effects in almost every organ system. Dr. Carlisle: Yeah, and one thing I always emphasize is that sleep deprivation isn’t just about feeling tired. It actually puts you in a physiologic state that’s very similar to being intoxicated. There are studies showing that being awake for about 24 hours can impair cognitive performance to a level comparable to being above the legal driving limit for alcohol. Dr. Arreaza: That’s actually kind of scary when you think about it.  Dr. Carlisle: It really is. Another way to think about it is sleep deprivation doesn’t just make you slower; it actually changes how you make decisions. People become more impulsive and less risky. And in medicine, we see that translates into increased medical errors, decreased attention, and poor decision-making. So, from a clinical standpoint, sleep isn’t optional; it’s foundational. Dr. Kim: Delay caffeine (but not too late), avoid alcohol, and focus on behavioral strategies (put away your phone 1 hour before bedtime).  Dr. Carlisle: And sleep is the foundation of performance. If sleep is off, everything else is compensating. Dr. Kim: And even beyond cognition, even one night of poor sleep can impair immune function and shift hormones that regulate hunger, which is why people tend to crave more food when they’re sleep deprived. Dr. Arreaza: I think it’s wise to dispel the myth of the “Russian Sleep Experiment”, have you heard about it? Dr. Carlile-Dr Kim: [reaction] Dr. Arreaza: The “Russian Sleep Experiment” is an internet horror story claiming Soviet scientists kept prisoners awake for several weeks using a gas. They developed extreme paranoia, violence, and self-mutilation. Then, the experiment got out of control, the subjects became unrecognizable, they refused to sleep, continued to deteriorate, and went insane. Even though the story went viral in 2010, it is fictional (reaction), with no real evidence that it really happened. So, it is just a made-up horror story. But there are some real studies about sleep deprivation in humans.  Dr Kim: Yes, the most famous case was Randy Gardner (1964) who stayed awake for 11 days. He developed hallucinations, memory problems, and mood changes. He recovered after sleep (no permanent “madness”). Dr. Carlisle: Sure, but as I mentioned before, even one night without sleep significantly reduces performance and accuracy. Dr. Kim: Another myth we fall into is “catching up on sleep”. It is a myth! Sleep Architecture Dr. Arreaza: Sleeping is a state when you reset your brain and your energy, but what actually happens during sleep? Dr. Carlisle: Sleep cycles between non-REM and REM stages. Non-REM sleep, especially deep, slow-wave sleep, is where physical restoration happens. That’s when you get growth hormone release, tissue repair, and metabolic recovery. Dr. Kim: And one of the most fascinating things is what happens in the brain during that deep sleep. The space between brain cells actually expands, which allows cerebrospinal fluid to circulate and clear out metabolic waste. Dr. Carlisle: That’s the glymphatic system. And what’s interesting is that this clearance is most active during deep sleep (Stage 3, Delta waves). It clears neurotoxins like beta amyloid, which is one reason chronic sleep deprivation is linked to neurodegenerative diseases, such as Alzheimer’s disease.  Dr. Arreaza: So, your brain is basically cleaning itself while you sleep. The “glymphatic system” is relatively new. It was described in 2010, and it clears substances like beta-amyloid, which is linked to Alzheimer’s disease. Dr. Carlisle: Exactly. Then REM sleep is more focused on brain function. That’s where memory consolidation, emotional processing, and learning really happen. Dr. Kim: And REM sleep tends to occur more in the second half of the night. So, when people cut their sleep short, they lose a lot of that REM sleep, which affects mood, focus, and overall cognitive function. What Drives Sleep Dr. Arreaza: So, what actually makes us feel sleepy? Dr. Kim: There are two main processes. The first is the homeostatic drive, where adenosine builds up in the brain the longer you’re awake, creating sleep pressure.  Dr. Carlisle: And the second is your circadian rhythm, which is controlled by your brain’s internal clock and influenced mainly by light exposure. Dr. Arreaza: So, in summary, one process depends on how long you’ve been awake, and the other process depends on your body’s own timing.  Dr. Carlisle: Exactly. I think of it as pressure and timing. Adenosine builds pressure, and your circadian rhythm determines when that pressure gets released. Dr. Kim: And when those two systems are aligned, sleep happens naturally. When they’re out of sync, that’s when people start having issues.  Morning Routine Dr. Arreaza: Let’s talk about practical tips. The morning seems to be a key element in our sleep. What can we do in the mornings to help us sleep at night? Dr. Carlisle: Morning sunlight, without a doubt. Getting light exposure within the first 30 to 60 minutes of waking helps anchor your circadian rhythm. Dr. Kim: And outdoor light is much stronger than indoor light, even on cloudy days. Dr. Carlisle: The mechanism is that light activates specialized retinal cells that signal your brain’s clock. That sets the timing for cortisol release in the morning and melatonin release later at night. Dr. Kim: And it also increases dopamine early in the day, which helps with mood, motivation, and focus. Dr. Carlisle: So, you’re not just waking up; you’re setting up your entire day’s physiology. Caffeine and Hydration Dr. Arreaza: Light exposure; I like the idea. That’s why phototherapy works for any kind of depression, not only seasonal depression. What other suggestions can you give us about our morning routine?  Dr. Carlisle: Hydration first thing in the morning helps restore plasma volume and improve alertness since we’re mildly dehydrated overnight. Dr. Kim: It is also a good idea to add electrolytes to the water. And caffeine timing is huge. If you drink it right when you wake up, you’re interfering with your natural adenosine cycle. Dr. Carlisle: Exactly. Caffeine blocks adenosine receptors, but it doesn’t remove adenosine. So later in the day, when caffeine wears off, all that built-up adenosine hits at once, and that’s what causes the crash. And that’s why some people feel wired but still tired because the underlying sleep pressure is still there, just being masked by the caffeine.  Dr. Arreaza: So, what should people do instead? (I say people because I personally don’t drink coffee, and occasionally I drink caffeine) Dr. Kim: People should wait about 60 to 90 minutes before having caffeine.   Even without trying, every night you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you, send us an email at [email protected], or visit our website riobravofmrp.org/qweek. See you next week!  _____________________ References: 1. Williamson AM, Feyer AM. Moderate sleep deprivation produces impairments in cognitive and motor performance equivalent to legally prescribed levels of alcohol intoxication. Occup Environ Med 2000;57(10):649-655. 2. Xie L, Kang H, Xu Q, et al. Sleep drives metabolite clearance from the adult brain. Science. 2013;342(6156):373-377. 3. Walker MP. Why We Sleep: Unlocking the Power of Sleep and Dreams. Scribner; 2017. 4. McMorris T, Harris RC, Swain J, et al. Effect of creatine supplementation and sleep deprivation on cognitive performance. J Sports Sci. 2006;24(3):305-313. 5. Turner CE, Byblow WD, Gant N. Creatine supplementation enhances corticomotor excitability and cognitive performance during sleep deprivation. J Sleep Res. 2015;24(3):307-315. 6. Gordji-Nejad A, Matusch A, et al. Creatine supplementation and brain energy metabolism during sleep deprivation. Sci Rep. 2024;14:54249. 7.  Wienecke E, Nolden C, et al. Magnesium and sleep quality: systematic review. *Med Res Arch.2021. 8. Theme song, Works All The Time by Dominik Schwarzer, YouTube ID: CUBDNERZU8HXUHBS, purchased from https://www.premiumbeat.com/. Even without trying, every night you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you, send us an email at [email protected], or visit our website riobravofmrp.org/qweek. See you next week!