HOW SLEEP IMPACTS INSULIN, BLOOD SUGAR, AND METABOLIC HEALTH
For most people, all it takes is one night of sleep deprivation to recognize how important sleep is to overall health. Brain fog, fatigue, and moodiness are some of the most obvious side effects of poor sleep – but what's happening inside your body when you skimp on sleep?
Research shows that lack of sleep can set the stage for metabolic mayhem, including issues like weight gain, impaired glucose metabolism, heart disease, and more.
In this article, we'll explore why prioritizing healthy sleep patterns is vital for metabolic health and insulin sensitivity for those managing diabetes as well as non-diabetics.
What Is Metabolic Health?
Metabolic health describes the vast ways in which we generate and process energy in the body. When all of these systems are working efficiently, you'll have steady energy, your heart should be in pretty good shape, and you'll likely be at a weight that's right for you. Unfortunately, conditions impacting metabolic health are rampant these days, which is why researchers are beginning to focus more and more on how we can enhance metabolic health and prevent disease.
It should be noted that your "metabolism" in terms of how many calories you burn each day is just one facet of the overall metabolic health picture. While effectively breaking down and burning the calories you consume can help with weight maintenance, an even more crucial aspect of metabolism is the role that your hormones play in managing your blood sugar.
In fact, you could say that the crux of metabolic health is the relationship between insulin and blood sugar. When your insulin is working properly, and your blood sugar is stable, it creates harmony within your metabolism. However, when blood sugar issues arise, it can impact every system in your body and set the stage for metabolic syndrome.
How Sleep Impacts Blood Sugar and Metabolic Health
Short-Term Sleep Deprivation Can Increase Insulin Resistance
Insulin is the hormone that shuttles glucose out of your blood and into your cells. However, this process doesn't just happen effortlessly; first, insulin must communicate with your cells to let them know there's some glucose hanging around. Once your cells get the message, they present with transport proteins on their surface that allow the glucose in.
When someone has "insulin resistance," it means that insulin is in the blood trying to communicate with your cells, but your cells are not hearing the message – they are resistant to the information insulin is trying to send. As a result, glucose remains in the blood and builds up, causing high blood sugar.
This is a common issue for people with type 2 diabetes, but research shows that healthy people that are sleep deprived may also start to experience insulin resistance. In fact, one study found that as little as six nights of sleep deprivation stimulated insulin resistance with a 40% decrease in the ability to clear glucose from the blood.
Furthermore, the authors note that in just six days, the healthy volunteers exhibited metabolic profiles similar to those with full-blown type 2 diabetes.
Less Sleep Equals More Insulin
If short-term sleep deprivation creates insulin resistance, what happens when you chronically get less sleep than your body needs?
In a study measuring "short-sleepers" (sleep duration of 6.5 hours or less per night) vs. "normal sleepers" (7.5 to 8.5 hours of sleep per night), researchers found that short sleepers had to secrete 50% more insulin than the normal sleepers to attain healthy blood sugar levels.
The problem here is that although insulin was achieving its goal of keeping blood sugar stable, a constant onslaught of this hormone could eventually lead to insulin resistance and, ultimately, type 2 diabetes or metabolic syndrome.
Interestingly, research also shows that getting too much sleep may also impact metabolic health. So, where's the sweet spot? It appears that seven to eight hours of sleep each night is ideal for preventing insulin resistance.
Poor Sleep Quality Can Greatly Increase Risk For Type 2 Diabetes
Okay, so what if you're getting the recommended eight hours of sleep each night? Does that mean you're in the clear?
You also have to account for sleep quality, which means getting enough uninterrupted REM and deep sleep.
One study followed 2,649 men with no medical history of diabetes for eight years, assessing both their metabolic health and sleep quality. At the end of the study, the investigators reported that the participants with sleep problems had double to triple the risk of developing diabetes.
Sleep Deprivation Can Drive Unhealthy Cravings
One of the key contributors to metabolic syndrome and insulin resistance is obesity. While it's commonly believed that people that suffer from obesity simply eat too much, the truth is that it's their hormones calling the shots, not their conscious will.
Two hormones that play a vital role in weight management are ghrelin and leptin. Ghrelin, known as the "hunger hormone," stimulates your appetite and promotes the storage of fat in your cells[ Meanwhile, leptin is responsible for signaling to your body that you don't need any more food; it's the "satiety hormone" that keeps your dietary intake in balance.
The balance of these two hormones is crucial for weight loss and maintenance.
So, where does sleep come in?
Research shows that just two nights of poor sleep can disrupt the balance of these two hormones, increasing ghrelin production and inhibiting leptin. As a result, you'll not only feel hungrier when you don't get enough sleep, but you'll also crave foods specifically designed to increase fat storage – AKA calorie-rich, high-carbohydrate, and high-fat foods.
Staying Up Late Can Mess With Your Insulin Activity
What about the night owls?
Some people find they get their second wind around 10 pm, and they love to stay up and work, play, get creative, or whatever else it is that energizes them. While it can feel good to be living life while the rest of the world is asleep, there are some serious downsides to burning the midnight oil.
Research shows that even if you're getting eight hours of quality sleep, staying up late can still mess with your insulin due to the release of another hormone – cortisol.
When you stay up late, your body naturally makes more cortisol, also known as your stress hormone. This makes sense because biologically, your circadian rhythm (your internal clock) likes it when you go to bed somewhere around or before 10 pm. Once you get past 11 pm, many people find that they get a wave of energy – that's your stress hormones acting up.
Unfortunately, cortisol is a powerful antagonistic hormone for insulin, meaning that it can inhibit insulin signaling and secretion. As a result, your nighttime glucose levels become dysregulated, which could create problems over time – not to mention cortisol's direct impact on insulin.
Simple Tips To Enhance Sleep Quality
For someone that has issues with sleep, it can be frustrating to hear that you just need to "prioritize sleep better." If it were that easy, you would have done it already.
With that being said, many people are simply unaware of some of the simple steps they can take to get a better night of sleep. Here are some tips and tricks to help you get in tune with your body and finally get some quality sleep:
- Avoid looking at screens for at least an hour or two before bed (screens have blue light that can inhibit melatonin production).
- Instead of scrolling or watching TV, try reading a fiction book before you go to sleep to get the creative part of your brain activated while shutting down the analytical side (which is well known to keep you up mulling over this or that).
- Don't eat anything for two to three hours before bed unless it's a light snack. Food in your stomach can keep you up as your body is busy digesting.
- Journal before bed to get any anxious or stressful thoughts out of your head and onto the paper.
- Turn the lights down in your home after sunset to mimic what's happening in nature. Your body wants to follow a rhythm that matches the natural environment but gets confused by bright lights and loud noises.
Getting a good night's sleep is one of the most important things you can do for overall health and wellness. It not only impacts how you feel the next day, but the long-term consequences of sleep disturbances can be devastating to metabolic health.
Research shows us that poor sleep hygiene can set the stage for prediabetes, type 2 diabetes, and metabolic syndrome. By increasing your cravings for fat and carbs while reducing insulin efficiency, you have the perfect storm for sky-high blood glucose levels.
And, of course, higher blood sugar often leads to insulin sensitivity issues, further driving glucose intolerance and impaired glucose control.
If you struggle with sleep, it can be helpful to train yourself how to wind down at night. Give some of the tips above a try, and if you're still having trouble with sleep, you can work with specialists that focus on tackling sleep issues.
- Knutson, Kristen L. "Impact of sleep and sleep loss on glucose homeostasis and appetite regulation." Sleep medicine clinics 2.2 (2007): 187-197.
- Wondmkun, Yohannes Tsegyie. "Obesity, insulin resistance, and type 2 diabetes: associations and therapeutic implications." Diabetes, metabolic syndrome and obesity: targets and therapy 13 (2020): 3611.
- Hirotsu, Camila, Sergio Tufik, and Monica Levy Andersen. "Interactions between sleep, stress, and metabolism: From physiological to pathological conditions." Sleep Science 8.3 (2015): 143-152.
- Schernthaner-Reiter, Marie Helene, et al. "The Interaction of Insulin and Pituitary Hormone Syndromes." Frontiers in Endocrinology 12 (2021): 626427.
- Pradhan, Geetali, Susan L. Samson, and Yuxiang Sun. "Ghrelin: much more than a hunger hormone." Current opinion in clinical nutrition and metabolic care 16.6 (2013): 619.