#191 – How sleep affects metabolic health | Azure Grant & Ben Grynol

Episode introduction

Show Notes

Sleep deprivation can be detrimental to metabolic health—even a short night of sleep, poor quality sleep, or low sleep efficiency can have significant impacts. Not getting a full, high-quality night’s sleep may be why you’re so hungry, but can also set you up for decreased insulin sensitivity, which when compounded, can have worse long-term effects. Listen as Research Design Lead Azure Grant talks with Ben Grynol about the importance of quality sleep for metabolic health.

Key Takeaways

03:14 – Sleep disruption leads to hormonal changes

Even one night of sleep loss can have a massive effect on your hormones. Evidence of this can be observed with several hormones such as glucose, insulin, glucagon, and C-peptide (a precursor to insulin).

Studies into the effects of sleep loss on your hormones and metabolic health initially focused on cases where severe sleep disruption had occurred. However, research shows that even one night of sleep loss can result in significant hormonal changes. One night of total sleep loss can cause an increase in C-peptide, which in turn causes an increase in your insulin levels the next day. Glucagon, one of the hormones responsible for regulating your blood sugar levels, falls, which may make it harder to regulate your lows. Leptin which regulates your energy and helps create satiety also decreases.

04:38 – Poor sleep is making you hungrier

All of the hormones affected by sleep loss contribute to making you feel hungrier. They also cause your metabolic system to work less efficiently.

It’s not unusual to get a little rumble in your stomach when hungry. This rumble is caused by ghrelin, often called “the hunger hormone”. Ghrelin is produced in your stomach. Its primary function is to signal your brain when your stomach is empty, and you need to eat. However, ghrelin isn’t the only hormone responsible for making you hungrier. The entire cocktail of hormones affected by sleep loss contributes to making you hungrier. It also causes your metabolism to work less efficiently. Waking up more ravenous than usual in the morning could result from sleep disruption. This sometimes causes people to make poor food choices in the morning, priming them for an insulin spike.

05:59 – Just one night of sleep loss can make you a little more insulin resistant

People often assume insulin resistance takes a long time to develop. However, insulin resistance can change rapidly – even within hours – and even short-term sleep loss can affect it.

Insulin resistance is dynamic and can change in hours to days. As little as one night of sleep loss or poor sleep quality can affect your insulin resistance. A lot more research needs to be done to understand just how big and how variable this impact is, especially with short-term sleep loss.

09:23 – No one is immune to the effects of sleep deprivation, but exercising can help

There’s a misconception that young people are better equipped to handle sleep loss and its effects on metabolic health.

Research shows that being young, healthy, and fit doesn’t protect you from developing insulin resistance. In fact, drastic changes can occur in a relatively short window of time. Unhealthy sleep and nutrition habits can suddenly cause you to develop temporary insulin resistance. However, being physically fit does go a long way in helping to regulate your insulin levels, especially if you have poor nutrition and sleep habits. A sedentary lifestyle can cause your body to pump out more insulin than it needs. Over time this can lead to worsening insulin resistance.

15:45 – Sleep quality is as vital as sleep duration

Only about one-third of people get the recommended eight hours of sleep every night. However, this number doesn’t consider the quality and efficiency of sleep they are getting.

While it’s essential to get the recommended seven to nine hours of sleep every night, ensuring that each of those hours is uninterrupted and quality is also necessary, waking up to use the restroom multiple times a night or tossing and turning affects your sleep efficiency. It’s not enough to simply spend eight hours in bed at night. It’s crucial to sleep soundly to ensure that all the bodily processes that occur in your sleep happen efficiently. Getting the recommended hours of sleep but having low-quality sleep can affect your insulin resistance in more ways than you might realize over time.

17:40 – Getting less than six hours of sleep can be significantly disruptive

Less than six hours of sleep in just one night causes significant disruption to your metabolic health.

It’s established that the average adult needs an average of eight hours of sleep to function efficiently. Sleeping for less than six hours a night is a massive drop-off point from this number, which affects most people’s daily functioning. However, sleep is highly individual; some people may appear to function effectively enough by sleeping for six hours or less. However, research shows that the short and long-term effects of this are detrimental even to young, fit, and healthy people. Aiming to sleep for at least eight hours daily is a great goal. Another thing to note is that while it may feel like your body can function on little sleep, the fact is your body has simply become used to being tired.

20:22 – Oral glucose tolerance tests can be an early indicator of insulin resistance

Oral glucose tolerance tests are used as a screening tool for gestational diabetes in pregnant people. It can also give some insight into insulin sensitivity.

If you are not used to getting glucose spikes, sitting down and doing nothing after having a high-carb meal can make you feel sick. An oral glucose tolerance test is conducted by administering a high amount of glucose and then monitoring how your body responds to it. If you are insulin resistant or in an insulin-resistant state, your body will respond by pumping out extra insulin. You’ll also observe a spike in glucose which will take longer to come down. While this test isn’t typically done to measure insulin resistance. Some research shows that when sleep loss causes a person to become more insulin resistant in the morning, they are likely to perform poorly on an oral glucose tolerance test.

24:09 – The link between obstructive sleep apnea and metabolic health

Having healthy sleep habits and getting enough sleep can be disrupted by confounded by conditions that affect the quality of your sleep, such as obstructive sleep apnea.

Obstructive sleep apnea is a condition that causes you to stop breathing while you sleep. This could be because of an obstruction in your airways or miscommunication between your body and brain. While most people with the condition don’t realize it, sleep apnea causes you to wake up several times at night so you can breathe, disrupting the quality of your sleep. This disruption to the quality of your sleep contributes to insulin resistance the next day. One of the most significant risk factors for sleep apnea is obesity or excess weight, which has historically been linked to poor metabolic health. People who fall in this category and experience sleep loss due to obstructive sleep apnea are faced with a compounded problem.

27:35 – You can track your sleep efficiency with wearables

In the past, the most effective way to measure sleep efficiency and diagnose conditions like sleep apnea was to get a formal sleep study. Today, there are tools to help you do so at home..

One of the biggest challenges faced by people trying to monitor their sleep hygiene used to be that it could only be done in a sleep lab. Today several apps, tools, and wearables can help you measure your sleep duration and quality. Wearable sleep trackers like fitness watches and SpO2 rings can help you efficiently track your sleep. Some apps can detect when and how loud you snore, a common symptom of sleep apnea. These tools might only sometimes give perfect data, but they are a great place to start. Being proactive about your sleep hygiene helps you stay ahead of any potential problems, especially concerning your metabolic health.

33:17 – Build better sleep habits one day at a time

It’s never too late to get back on track with healthy sleep hygiene. This starts with building better sleep habits.

Getting off track with poor sleep habits is typical and expected. The most important thing to remember is that getting back on track is crucial. As mentioned, as little as a single night of sleep loss can significantly affect insulin resistance. The good news is that, in turn, as little as a single night or week of sound sleep in terms of duration and quality can also result in quick improvements. In addition, healthy habits become even more critical when you’ve had some sleep loss. Lowering your carb intake, maintaining a nutritious diet, exercising, and increasing your fasting window as you work to get back a healthy sleep routine is essential. While focusing on your sleep gets a lousy rep culturally, it’s one of the most crucial ways to improve your metabolic health and general well-being.

Episode Transcript

Azure Grant (00:06):

There’s already so much known about how detrimental sleep loss is. I think the harder work to do here is to help people see in the moment that that amount of sleep loss that you just suffered, even though it wasn’t an all-nighter, you are turning that dial in the direction of insulin sensitivity. And that focusing on your sleep, although it might seem culturally like the lazy thing to do, is one of the best investments that you can make in improving pretty much all aspects of your health.

Ben Grynol (00:45):

I’m Ben Grynol, part of the early startup team here at Levels. We’re building tech that helps people to understand their metabolic health. And this is your front row seat to everything we do. This is a whole new level.


Sleep loss is something that many people can relate to. It happens from time to time. Some people it happens frequently and others infrequently, depending on their sleep hygiene. Well, what is the impact of sleep loss or compounded sleep debt on glucose levels? It really does in fact start to impact your variability, your average glucose levels in a day. Even things like your cortisol. It gets elevated with sleep loss. And so, Azure Grant, part of the research team, she and I sat down and we discussed this idea of sleep or sleep loss and the impact on metabolic health. There’s so many downstream implications to sleep loss and as it compounds over time how many hours of sleep a person gets in a night, not just the duration but the overall quality. Well, it can have pretty significant impacts on downstream metabolic health. So anyway, no need to wait. Here’s where we kick things off.


So sleep and glucose, we know that we, and by we, I mean many people in society don’t often get enough sleep from time to time. And this can come down to many factors that are in our control and some that are not in our control. So things that are in our control, we stay up late and we doom scroll TikTok or Instagram, never good. We stay up late. We binge watch one extra show on Netflix because we go for short term reward over long term benefits. We stay out late with friends instead of going home to rest. We sometimes have kids wake us up. There are all these factors that cause this lack of sleep. And so the biggest thing to consider is that when you have a bad night of sleep or sleep loss, there are so many downstream metabolic impacts that are important to consider. Why don’t we good to go into this idea of what happens when there is significant sleep loss in the near term and then over time how that can impact metabolic health.

Azure Grant (03:12):

Sounds great to me. One of the first things that I want to call out is that sleep loss is a gradient. So a lot of us might miss one hour of sleep, two hours of sleep, or have more fragmented sleep. While most studies, at least historical ones that have measured hormonal time series, have looked at very serious sleep restriction, like an entirely lost night of sleep and all nighter or restriction to four hours. So some of the things that we’re going to talk about today, we’re going to be interpolating from a really severe sleep restriction to what might be happening in the modern environment. And I think this provides a lot of interesting examples for us to build on with our own data set. In terms of looking at the full gradation of sleep loss. Should we get into some of the scary hormones?

Ben Grynol (03:57):

Let’s do it. Let’s talk about hormones, glucose, and how all of this unfolds.

Azure Grant (04:02):

Okay, so first off, when people were studying sleep loss in relation to metabolism, looking at glucose, insulin, glucagon or hunger hormones and people’s subjective writings, as I said, they started out by looking at pretty severe sleep loss. So for example, if you restrict someone’s sleep entirely for a night, so you pull one all nighter, which a lot of parents have probably done pretty recently and a lot of college kids have probably done pretty recently. You increase C peptide, which is a little upstream thing that helps make insulin and you increase insulin the next day. You also increase the hunger hormone, grelin. Makes your stomach rumble and increases those contractions. You also disrupt the rhythm of cortisol, which we can get into a little bit more. Things that go down, glucagon goes down, which is a hormone that helps you control your lows throughout the day.


Leptin, a thing that would normally be giving us a sensation of satiety released from the adipocytes that goes down. And even TSH, thyroid stimulating hormone, you might have heard it called thyrotropin, that goes down as well. So we can unpack these one at a time, but the entire suite of changes that occur with a full night’s loss of sleep disruption and then with severe sleep loss, thinking half a night of sleep is gone. That all combines to make you hungrier, have a harder time getting full, be a little bit more stressed out and have your entire metabolism working less efficiently.

Ben Grynol (05:37):

So there’s this scenario that many people can relate to in one way or another, which is you get on this cycle almost where you wake up hungry, right? You’re hungry, maybe you’re irritable, there are all these things going on behind the scenes, cortisol is up, your glucose has less stability, it’s maybe higher average glucose levels for the day, more variability. And because of all the things that are going on at the hormonal level, you go and you grab that bagel in a coffee because you got to wake up. And then what happens?

Azure Grant (06:10):

Well I think you point out a really interesting thing, which is in studies of partial sleep restrictions, say where you’re getting four hours of sleep a night for a week. The biggest difference in terms of rating of hunger between control groups, so with normal sleep and the groups that have that sleep restriction is in the morning when they wake up. So around 9:00 AM they’re super hungry compared to how they would be otherwise. And so what happens when you wake up extra hungry due to your sleep disruption, maybe your willpower is a little bit down, you’re a bit groggy. If you’re more likely to reach for that sweet breakfast, you’re almost double primed to have a spike after it.


So first, if your food choice is likely to be a little bit worse due to your hunger and cravings, you’re primed at the same time to be a little bit more insulin resistant, and that means a bigger spike after that meal. I think this is also an interesting thing that we could use to talk about insulin resistance and how fast it can change because I think a lot of people, including myself for a long time thought of insulin resistance as maybe this state that changed slowly over time while other things like glucose and insulin were changing pretty fast. But as we’ve been learning, it seems like insulin resistance is a dynamic property in our bodies that can change every few hours and absolutely respond to something like a short term loss in sleep.

Ben Grynol (07:42):

So then how many nights? It is pretty typical where… Let’s use this scenario. You’re a student, maybe you’re professionally working on some project and you have three, five, you have N number of days. What’s that in as far as the number of days until you start to see significant impacts where you’re going. Wow, this is not a good trend to keep on. I guess, what’s a number of days and what’s the amount of sleep when we start to talk about these levels of sleep that make that significant impact.

Azure Grant (08:13):

So people have shown as little as one day of something like half of the night of sleep or a full night of sleep loss generates these changes that I just spoke about with increased insulin, probably local increases in insulin resistance and all those hunger issues. So that can happen as quickly as you slept really poorly last night or say you got up four hours early because you have to catch a flight. But I think the question that you’re getting to is where’s the gray area where if say for the next week, if I lose two hours of sleep for two nights or if I lose one hour of sleep for four nights, what’s the difference there? And that’s something that seems like it still needs a lot more active study, especially to be able to make claims or to understand what’s going on at the level of the individual.


And that’s one of the things that I think is most important about this discussion today, is how we can now bring in data from sleep wearables that actually have better sleep staging potential than a lot of historical sleep wearables like the ACT watch and study people in their natural environments of their home beds rather than bringing them into a sleep lab, which is a very artificial and disruptive environment on its own. And I think that, in combination with the CGM data, is what’s going to allow us to make those much more fine grained personal statements about how sleep and blood glucose relate. Because right now it’s fairly broad strokes. We know big interventions hitting it with a hammer can very quickly lead to increases in insulin resistance.

Ben Grynol (09:50):

Why don’t we get into the idea of, we’ll call it age and metabolic fitness. Because I think there’s this big misconception that happens where we think like, oh, it’s fine that person is physically fit, whether or not that’s a correct heuristic, based on everything we know around insulin resistant and how people metabolize different foods. Let’s use that misconception where it’s like, ah, they’re young, it doesn’t matter. They can go without sleep, they’re fit. And we go down this irrational path.


But from what we’ve learned, insulin resistance, you can’t bucket it out. There’s been research that’s show young healthy fit people can change in a very short window of time where, all of a sudden they go from being metabolically healthier, metabolically fit to maybe eating the wrong foods and having things like reduce sleep cycles over a period of time. And all of a sudden they start to develop this interim insulin resistance and you go, wait, how did that happen? That’s Alex, the young athlete, he plays professional hockey. How did that happen? But, I guess the takeaway is like no one’s immune to this, we’re all exposed and it’s how we manage it.

Azure Grant (10:58):

Yeah. Well one thing that I would call out is I think that the physical activity does help a lot. If you’re going to do one thing while you’re eating a bit more poorly or not sleeping enough and that’s keeping a regular activity rhythm and particularly exercising hard, getting your heart rate up, exercising after you eat something, that does help a lot. But I do agree with you that it seems like no one is immune. And you’re alluding to some of the work by Jerry Schulman and others, and he explains this very elegantly, about how you can take young people who are maybe late teens to early twenties who aren’t overweight yet, they are sedentary so they’re not exercising. But these people show signs of insulin resistance even though if you were to look at them externally, they’re fine, even though they don’t have high fasting blood glucose, they’re already showing signs specifically in the muscle where they’re not able to efficiently get glucose uptaken by the muscle and they’re starting to pump out more insulin than they need.


And this is a cascade that would over a long period of time lead to worsening insulin resistance, inflammation, especially in the fat and then more gluconeogenesis. And that would eventually raise the fasting glucose level. Sleep, I think is something where the mechanisms that lead to the insulin resistance might be a little bit more complex or augment the ones that are normally at play. But to your point about young people, yes, sleep loss is absolutely detrimental to young people and there’s a lot of interesting work in test performance or school choice performance showing that if a student has a mismatch between when they would naturally go to sleep and wake up, their chronotype, and when they’re required to take tests or when they have their classes, they’re going to do worse in those classes and the students are also going to do worse if they have to do things late at night.


And so this kind of cognitive impairment is something that’s very visible even in fairly young students, and that just gets worth worse with late sleep and sleep loss. And you can imagine how these things probably compound each other that it’s not just the immediate impact of sleep loss itself on metabolism and on the brain. There’s probably an interaction between the two where when you’re sleeping less, you are also staying up later, probably eating later at night when most people are less insulin sensitive anyways. And that you would then get a combined effect of you’re losing sleep and you’re eating at the wrong time of day and so on and so forth.

Ben Grynol (13:39):

Yeah, chronotype is such a fascinating rabbit hole that we could go down. But the idea to digress for a sec is that we have a world that’s not designed around chronotypes. It’s designed around 9:00 to 5:00, and that causes so many challenges for so many people because you are forced to be your best self, assume all other conditions equal and you are eating well and you are sleeping well according to the 9:00 to 5:00 schedule and end to end exercising. It gets very challenging because there are other outside factors that are influencing the way that you feel best or the way that you physically should be performing your best based on your genetic makeup.

Azure Grant (14:22):

I mean I think part of the issue is that at this point, even 9:00 to 5:00 would be preferable to a lot of what people are doing. At least 9:00 to 5:00 is a stable circadian schedule. I think especially in the last few years since more has been done online, school has been online, there’s been an increase in communication online across time zones. If you can imagine we have a sign wave where in traditional society everyone would get up, go to work at the same time, maybe share meals together and now we’re more spread out. And that’s kind of a flattened curve where you’re having less of a peak in the middle of everyone doing the same thing at the same time and everyone’s physiology being aligned both within the person and the group that they’re part of. And you’ve got more activity at the low points where when you’re supposed to be taking a risk, now you’re taxing your body a little bit.


That’s one of the definitions of circadian disruption, is you get a flattening or a lowering of the amplitude of all the different rhythms, whether they be behavioral or metabolic or the sleep wake cycle. And I think that’s part of the issue. At this point if we could only go back to 9:00 to 5:00 and then get to bed at a stable time, that would probably be a big improvement already. And a lot of the losses in sleep that you see, they start to get a lot worse around the nineties and in early two thousands in parallel with our tech use going up.

Ben Grynol (15:54):

And so let’s go to 1942, when we started to have some of this research around how long people would sleep on average over the course of a night and how that has changed now. So what percentage of adults are sleeping seven plus hours a night? And then what does it look like as far as you go further down the tail? How many people are sleeping less than five hours? We know that objectively this is very unhealthy for people to do as far as a consistent behavior.

Azure Grant (16:27):

Yeah. So right now, well at least as within the past decade as a bucket, around 40% of people are sleeping six hours or less. And I think that number has only gone up over the last decade. Whereas if you look at the bucket that was sleeping six hours or less, even in 1990, that was less than 30% compared to 40%, and then back in the forties and our grandparents generation at this point, that was 8% of people. So this has been a really fast, really big change. And the number of people sleeping eight hours or more per night and the standard recommendation, that’s only about a third of people right now and maybe even less. And one thing that these numbers don’t get at is the fragmentation of sleep. So this is talking about how many hours do you usually sleep at night asking a person to respond.


It’s already a foggy measurement. But it doesn’t take into account things like, how many times did you wake up to use the restroom in the middle of the night, or how much did you toss and turn? What was your sleep efficiency, which is the ratio of how long you were spending in bed and how long much at that time you were actually asleep. And I think that is probably kind of a lurking big factor and sleep disruptor. Because it’s well known that if you don’t sleep as soundly, none of the processes of sleep, the linking together, the sleep stages happen as efficiently if you don’t get as much restorative sleep, and that has its own set of negative consequences down the line.

Ben Grynol (18:02):

What’s the amount, as far as hours go in a night where we start to see these impacts? Is it less than seven hours, is it less than six? Is there an amount? And it’s not about being prescriptive saying have the exactly this amount, but is there a delta where all of a sudden you go, holy smokes, the impact, the delta between six and seven hours is a significant impact. Is there any research around that?

Azure Grant (18:26):

Yeah, I mean, if you’re getting less than six hours of sleep, that’s a pretty big drop off point where most people don’t seem to be able to do well on that. But it’s individualized. It also depends on when the sleep is occurring. So there is no magic number. I think the goal of aim for eight hours of sleep if you can, is a very good goal for most people. People also can feel like they’re adapting to sleep loss over time. So let’s say if you slept six hours a night for the last two years, even though your body naturally wanted to sleep eight, you might feel at that point you’re adapted to being a short sleeper. It’s not that it’s actually true, it’s just that you’re very used to being tired at that point and probably, the feeling of the insulin resistance that comes with that.


So I think the overall goal of amount of time to be asleep shouldn’t change, and probably more people than are actually true feel like they’re able to successfully get by on less sleep. Once you get down all the way to four hours, then you get really, really big hits. And that’s, I think, part of why this has been the intervention time tested in a lot of the early two thousands or late nineties studies on sleep loss.


But the question you’re asking, I think part of it isn’t known, and this is something that makes me really excited about the fact that we can pull in sleep data now from health kit. Because what you want to see is the regression of say spike size the next day to the number of hours you slept the night before. Or spike size the next day compared to the relative amount of sleep you lost last night compared to your last week. Those questions I haven’t seen clear answers to. And my guess is that there’s probably some exponential relationship where the farther you go into sleep loss, both absolutely and relatively, the worse insulin resistance you get locally the following day. But we still need to find out.

Ben Grynol (20:30):

And so then what are we seeing with glucose? Like you said, that the more sleep loss there is… On average, you’re seeing higher spikes, are we getting more variability or is it harder to recover? Is it higher average glucose levels in a day where you’re sitting at this elevated level? What does that look like or is it different for everyone?

Azure Grant (20:50):

Well, so first what I just said, those were hypotheses. Those aren’t like we’ve already figured this out with our data. If we had gone in and figured that out already, that would be awesome and we should be sharing it with the world. I think this is a big project that we need to dedicate time to as quick as we can. But basically what’s already been shown is often from oral glucose tolerance testing. Do you think that’s like a concept worth giving a little bit of framing around?

Ben Grynol (21:16):

Let’s do it.

Azure Grant (21:17):

So the oral glucose tolerance test is something that you’ll see most of the time now prescribed for women who are pregnant as a screening tool for gestational diabetes. It’s not as often now prescribed by endocrinologists for people outside the context of pregnancy. But what it, is a specific amount of glucose, usually quite high, around 75 grams even. And that amount of glucose is taken in the morning-ish hours and then you sit down and you wait for your spike. And if anybody listening remembers the Coke challenge at levels or if you’ve ever had a big carb meal and then sat down and do nothing, you probably know the feeling of this can feel quite bad if you’re not used to a spike or can be quite a surprise and probably at least make you a little tired if you are used to spiking.


And the point of the oral glucose tolerance test is to evaluate how your body dynamically responds to a carb load. So if you are in an insulin resistant state, your body is going to be already pumping out extra insulin, because it needs a stronger signal in order to tell the cell, hey, you really need to get that glucose transporter up to the surface and let this glucose we got hanging around into the cell. But if that process is less efficient, which it is in the insulin resistant person, then you’re going to see more of a glucose rise and glucose is going to take longer to come down. And the reason that you have to do this test is that the dynamics of glucose and insulin are different than just glucose or insulin at the fasting state. So the problems in being able to respond to a glucose load happen before you get elevations in fasting glucose and insulin.


And I think there’s probably a lot of other podcasts that you’ve done that cover this material in more detail. But basically you can be showing evidence of big spikes or worse oral glucose dynamics for years before you get to the point where the body would be raising fasting glucose levels. So it seems to be a much earlier indicator. And so to relate this back to sleep, when we’re looking at short term changes in insulin resistance, say you’re more insulin resistant the day after you’ve lost a night of sleep, what I would expect that to show up as first and what people have found is that this looks like worse performance locally on that oral glucose tolerance test. And my guess would be that if we look in all of the behavioral data we have from people eating a variety of foods, that you would see worse spikes, overall taller spikes, ones that take longer to come down, and you could even consider this, every food that you eat is in some way a test of your glucose tolerance or your insulin sensitivity. And so that’s going to get worse when you’ve lost sleep.

Ben Grynol (24:14):

And so let’s make the assumption that somebody is… Everyone’s always trying their best. You’re always trying your best to eat well, to exercise well. There’s positive intent. You want to be healthier and feel better. And so if you subscribe yourself to certain behaviors, that being eating well, consistently exercising well, undertaking good sleep hygiene, like going to bed at 9:00 PM and having a nice shutdown routine, you’re not exposing yourself to screen time and all the things that can be sleep disruptors. But there is this confounding factor that a person might not be aware of. And that’s something like OSA Obstructive Sleep Apnea, where that has an impact on sleep. So you’re trying to do all of these things. Well, how much do we know about that impact of OSA on sleep duration, sleep quality, and how that can impact metabolic health.

Azure Grant (25:16):

So by definition, obstructive sleep apnea where you’re having bouts where you’re not breathing in the middle of the night, that’s going to disrupt your sleep because even if you don’t consciously know that you’re waking up, those precipitous drops in your blood oxygenation, those put your body into a stressful state and it wakes you up a little bit to get you to breathe. And if you’ve ever been in the room with someone who has sleep apnea and they’re sleeping, it can be quite scary. They’ll stop breathing for a little while, and then all of a sudden they’ll get this big gasp as if they’ve just been startled. And so that process of waking yourself up because you’ve stopped breathing, and potentially doing that all night long, that’s very disruptive to sleep quality, even if the overall sleep duration looks quite normal.


And that’s what I meant about this overall chart where you have these national surveys and you ask people how much they’re sleeping, you’re not asking people how much they’ve woken up. And in the case of sleep apnea, this is something that goes along very closely with being overweight. So one of the big risk factors for OSA is high weight, specifically if you get fat around the neck, that can drive OSA, and diabetes tends to correlate with OSA. So as far as the direction of causation, if you have sleep apnea alone, can we measure that that directly is causing your diabetes? I think it’s probably too much of all things correlating in that case. However, it logically makes sense that if you’re disrupting the quality of the sleep, you’re going to be also contributing to that insulin resistance the next day. And that’s probably part of the problem overall. And if you’re already on the road to insulin resistance and if you already have excess weight that’s contributing to the obstructive sleep apnea, this is probably compounding the problem.

Ben Grynol (27:13):

Correlation is not causation, and which comes first, we’ll never know. But that’s a hard thing is that you can’t find out whether or not you have apnea unless you have a proper sleep study. And sleep studies aren’t something that we do at home right now by ourselves. There are things that are significant inputs to our sleep quality, but it becomes this cycle of maybe you don’t eat well or you don’t exercise well, you don’t sleep well. And over time you become insulin resistance, you become overweight, you start to develop apnea, and then it gets a lot harder to get out of that cycle. And so even if you have, and that’s back to that question of, even if you have good sleep routine, and you think your duration is great, but your quality is low, then that puts you on this path of not being able to mitigate the insulin resistance in the way that you think you are or the way that you want to. And that gets to be a very dangerous path over time.

Azure Grant (28:17):

Yeah, right now I think that there are some really good tools that without a sleep study that if you are concerned, you might have sleep apnea or you’re concerned, you might have sleep disruption, you have a ton of more information now at your fingertips than you had in the past. So for instance, SpO2 rings, I think there are at least a few on the market now. These are pretty good at detecting the dips in peripheral pulse socks that occur during sleep apnea episodes. There are several snoring apps that are actually really good. They just use the mic on your phone and they tell you when you’re snoring, they even tell you the amount or the volume of your snoring, which can get quite loud and in someone with apnea. And then on top of that, the better sleep wearables, ones that are going to use heart rate and heart rate variability have a strong PPG signal.


They go beyond the simple activity measurement. Those can often give you a little readout of when they think you had woken up during the night. That doesn’t mean they’re perfect, but they’re a great place to start. Where if you are maybe subjectively, you get up and use the restroom or get up and go get a glass of water a couple times a night, if someone’s told you that you snore before, if you’re using a wearable and you notice that you have several wake ups or a relatively low sleep efficiency, or if you really want to get into it and solve your snoring, if you’re using a snoring app in combination with one of these SpO2 rings, that can give you a lot of clues that you might be suffering from sleep apnea. And I think in a lot of those cases, it can be hard to be as honest with ourselves as we should be about whether we’re really getting to bed with the right amount of time, whether we’re really making wise food choices early in the morning.


So, I think that’s always going to be a challenge, especially when you think about that the majority of people around you have the same problem and everyone wants to feel like things are still normal, but the reality is that things have changed very fast. So I think there are luckily a lot of tools out there that if you own up to it and say, Hey, maybe this is really a problem for me and I want to help myself and then get some help, if you can throw down a few hundred dollars, you can get a lot of the way there to knowing what the problem is.

Ben Grynol (30:38):

Yeah, it’s the importance of proactive health and monitoring multiple markers at one time, especially when we start to talk about biomarkers and being able to monitor multiple hormones in real time. Once we get to a state where we can be proactive and start to mitigate all of the things that can happen downstream, we understand health and wellness as far upstream as possible, then you start to get signal to say, hey, here’s happening in my body. Here are things that could be triggers to give you insight to say, why don’t I explore that further? And that’s the important thing with all of these conversations, is we always revert back to… They always seem to end in glucose is great and it’s amazing and we need to know a lot about it. But it is one of many, many markers when we talk about the future of health and wellness and why wearables are so important to it. It’s something that we need a lot more insight about what’s happening in real time in our bodies than we currently have. And there’s a lot of interesting research ahead.

Azure Grant (31:41):

Yeah, it’s true. I think luckily in the case of sleep, the story is very clear. We already know that sleep disruption leads to these hormonal changes that we talked about. Greater insulin resistance, it makes you hungrier, it makes you have a harder time staying full, it disrupts your cortisol rhythms, which contributes further to giving you high glucose and glucose volatility and probably makes you feel a little bit more stressed out to boot. So there’s already so much known about how detrimental sleep loss is. And I think the harder work to do here is to help people see, in the moment, that that amount of sleep loss that you just suffered, even though it wasn’t an all-nighter, you are turning that dial in the direction of insulin sensitivity and that focusing on your sleep, although it might seem culturally the lazy thing to do is one of the best investments that you can make in improving pretty much all aspects of your health.


Even that work that you think you’re not doing because you’re choosing to sleep more or even those social ties that you think might be weaker if you’re choosing not to go out, you’ll just be a better person and a metabolically healthier person overall if you prioritize this. So I think it’s an incredibly interesting set of research questions that we need to pursue as far as filling in that whole gradient of amount of sleep disruption correlated to glucose volatility as well as duration. But I think the behavioral story will stay pretty similar and it will be about driving home, well we already know, but with more detail to help people culturally change a little bit in the direction of sleeping a lot.

Ben Grynol (33:27):

So we know that best intent, behavior change, all the great things, someone gets off track, very normal, very understandable for a variety of reasons. What are takeaways that people can do if they do get off track with their sleep, especially if it’s something that… Let’s use a parent with a young child, they’ve got the best intention of getting sleep, they go to bed early, but they have these sleep disruptors. What can someone do to get back on track so that they can get back to a steadier state of less glucose variability and more stable glucose and overall feeling better?

Azure Grant (34:05):

I think the first thing is probably the attitude that your body is able to be resilient. So in the case of us saying that insulin resistance can come on really quickly with a single night of sleep, the converse is also true that if you choose to catch up and you’re able to catch up for even just a day, even just a week, those improvements can come back really quickly. And if insulin resistance can be made much worse acutely by very high intake of triglycerides or by that night of sleep or anything like that, you can also go back the other direction pretty quickly. So first it would be that you do have the power to make a change in the positive direction. After that, I think is being aware of the state you’re at. So if you know that you have slept less, even probably by an hour or two, than you ideally would in your recent history or long-term history, know that you’re right now set up for more insulin resistance than you otherwise would be.


And that the strategies that you can take to not tax your pancreas as much, so lower carb intake, increasing your fasting window in addition to working on your sleep, all those strategies are going to be a little bit more important for you. I think the awareness that particularly court can be higher in the afternoon and evening following sleep disruption, that one can also be kind of behaviorally powerful if you know you’re a little more likely to have your spikes continue throughout the day or to feel a little bit more stressed out, and therefore have that extra impetus to focus on same thing, those lower carb, higher protein, fibrous foods that are going to be less likely to set off your pancreas, that those are great interventions.


And then, of course, to sound like the broken record that we all need to be, activity can very quickly improve insulin resistance, as well as help bolster your circadian rhythm and make you tired enough to want to go to sleep again the next night. So, I think, regular activity is another one to add on top if you’re sleeping poorly and want to know what to do.

Ben Grynol (36:19):

So all good takeaways, provided someone’s willpower is high enough, is it safe to say that really thinking twice, so assume somebody has maybe one night or multiple nights of sleep debt that has accrued over time, provided somebody can have the willpower to do it. Would you say that those are probably the days where you should really think twice about indulging in something like reaching for that carb heavy croissant that you’re eating without fat fiber protein? Because the reality is everyone is going to indulge in some way, shape, or form at some time. But if you’re going to do it, we know if you’ve exercised that day, it makes a big difference. If you’ve eaten a lot of cruciferous vegetables and the way sequencing works, you’ve had a lot of great micronutrients that are feeding yourselves, that’s a different state than being in a sleep deprived state.


So is that something that you’d think through as far as if somebody was really thinking like, Hey, should I grab that breakfast sandwich, that carb-heavy bagel? Are those the days when you are, even though willpower, we know that’s a totally different conversation, that willpower and decision making is highly stressed when you are sleep deprived, but are those the times when you suggest that people really think about that because of the downstream impacts that it might have over the course of 24 or 48 hour duration that it just keeps compounding?

Azure Grant (37:47):

And sadly, this is the whole environmental mismatch. Our evolution wants us to pack on the pounds when we’re stressed out, or when something has happened wrong in our environment, because historically maybe that would’ve meant that times are hard and we should make sure that we’re stocked up for later and now we’re in the opposite situation most of the time. So yes, of course if when we are at our most tired and most stressed, we can remember, hey, this is really the time where I shouldn’t stress eat the cookie like I want to, then fantastic, don’t do it. But I think those periods of time when we’re low on sleep, when we’re high on hunger, when we want carbs, those are the times when your habits are most important. And so even if you are struggling when you’ve acutely had a really bad time and you’re not able to follow those habits that you know should or not able to follow those new extra good behaviors that you want to, and another thing you can do is work on building a good routine when you do feel a little bit better.


I know that everyone at Levels really likes the tiny habits framework for trying to set yourself up for success in small ways, and basically forming small routines, like going for a 10 minute walk after you eat something and on a good week do it every single meal. And then that’s a habit that maybe by the time you lose a night of sleep, you can still feel motivated to go out and do that walk. So I think that we know what the good habits are. It’s more about rather than chastising yourself for not having the willpower when you lack, it’s making the habits really strong when you are doing okay so that you can have a bit of an easier time when you lose your night of sleep. But I think this all comes back to sleep is one of the easiest things that you can do to give yourself a big boost. And if there is a way that you can focus on sleep as one of the pillars that your life is set up, and give yourself permission to consider it centrally important, then everything will get easier.