Blood sugar (or glucose) can have a significant impact on your sleep patterns. Did you know that it could even be the reason for your sleep problems?

The relationship between sleep and blood sugar is bidirectional. In one direction, your sleep directly affects your blood sugar levels (the next day). In the other direction, your blood glucose levels before and during the night’s rest affect your sleep.

Blood sugar affects sleep, and sleep affects physical health. Short sleep duration – less than seven hours in a 24-hour period – can have a significant impact on health. That explains why adults with too little sleep are at higher risk for chronic diseases such as diabetes, obesity and heart disease.

So getting your sleep habits under control has a positive impact on your health and life expectancy. We’ll show you how to do just that by monitoring your blood sugar levels.

Sleep is important for your body’s recovery process. When you don’t sleep enough, several changes occur in your body.

Sleep affects hormone levels and your circadian rhythm. The circadian rhythm naturally controls your sleep-wake cycle by responding to things like light and darkness.

A small group of nerve cells make up what is called the “master clock” in your brain. This internal clock controls hormone secretion, temperature, eating habits and digestion. For it to function optimally, a consistent circadian rhythm is required. 

If your circadian rhythm is out of sync, your body’s metabolic health can worsen – and you increase the chances for diabetes.  

Also a lack of sleep decreases insulin sensitivity, causing your body to produce more insulin to stabilize blood sugar levels. This eventually leads to glucose intolerance and diabetes.

Unfortunately, even a single night of insufficient sleep can impair the body’s ability to use insulin effectively.

Leptin and Ghrelin are two hormones regulating your appetite. Leptin has multiple roles in your body. Two of the main roles are long-term energy regulation and metabolism.
Let’s look at the mechanism behind it and why it’s related to sleep. 

The fat cells in your body release leptin to tell your brain when you have enough energy. When it is released, it suppresses your appetite and you feel satisfied. Low leptin levels will make you feel hungry. 

Several studies have found that short sleep duration lowers leptin levels, which leads to overeating and weight gain. The desire to eat more, in turn, leads to an increased intake of carbohydrates, which spike blood sugar levels.

Ghrelin has the opposite function of leptin: high ghrelin levels increase your appetite.These high levels can be the result of sleep deprivation. 

The increase in ghrelin level triggers a feeling of hunger, which leads to eating more carbohydrates, which in turn increases the blood sugar level.

In short: Sleeping less leads to more cravings and overeating and may be the reason for weight gain.

Lack of sleep or also insufficient sleep can increase sympathetic nervous system activity, controlling the fight of flight response. Lack of sleep can cause this “fight-or-flight” mode to kick in during the day and at night, releasing stress hormones such as cortisol. And cortisol can lead to chronically elevated blood glucose levels. The long term consequences of these high blood sugar levels include prediabetes, diabetes, or metabolic syndrome.

Research shows that sleep deprivation increases inflammatory levels in the body. Similar to the impact on insulin levels, this effect can occur after just one sleepless night. Inflammation is one of the body’s defense mechanisms, providing valuable protection against viruses and bacteria.

Glucose is the fuel for the brain. It provides the energy it needs to perform its functions. When sleep is deprived, the brain’s activity decreases significantly. You may have noticed that you can concentrate better after eating something sugary. At least for some time. 

As mentioned earlier, sleep helps maintain body weight in many ways, including regulating hunger hormones and insulin levels. Besides the hormonal impact, lack of sleep increases levels of free fatty acids in the blood. These high fatty acid levels reduce insulin sensitivity and hinder the body’s ability to metabolize fat.

We’re going to assume that these are enough reasons highlighting the importance of sleep.
So let’s look at your blood sugar levels when you sleep. 

In a healthy person, blood sugar levels rise and fall during sleep, which is normal. Some of the changes can be attributed to your sleep phases (usually lower during a REM phase), some may be the result to the glass of alcohol (big fluctuations) you’d consumed with your dinner, or it can also be connected to your circadian rhythm (with your liver being most active between 2-4 am).

In general, we’ve noticed that blood sugar levels tend to be lower during your sleep, then when you’re awake.
Currently, there aren’t any general recommendations for your blood sugar levels at night, but it seems safe to say that healthy ranges during the night are between 70 -100 mg/dl.
So yes, they can be lower than the optimal range of 80-110 mg/dl. However, if you notice that you wake up multiple times during the night and your blood sugar levels are in the lower range, we recommend optimizing your dinner and bedtime routines.

Another fascinating fact about sleep and blood sugar is the dawn phenomenon. 

The dawn phenomenon is a process that happens to everyone. In the early morning hours, certain hormones (growth hormone, cortisol and catecholamines) cause the liver to release sugar into the bloodstream. This process can cause a short-term spike in blood sugar levels. This is the body’s “natural alarm clock”.

For most people, the dawn phenomenon usually occurs between 4 and 8 am, depending on your sleep-wake rhythm. Your blood sugar levels should drop within a few hours again.

High blood sugar before bedtime can affect the nervous system, making it difficult to fall asleep and stay asleep through the night. This can trigger insomnia and increase cortisol and adrenaline levels, preventing your body from fully relaxing.

You may need to go to the bathroom more often, which disrupts your sleep. This is because your kidneys are trying to flush the excess glucose out of your body.

High blood sugar can cause you to feel dehydrated and wake up from sleep to rehydrate with a glass of water.

They can also make you feel hot, irritable and restless, making it harder to fall asleep.

Low blood sugar can occur in both diabetics and non-diabetics. It can also severely affect your sleep. Your blood sugar levels may drop due to stress, alcohol, insulin resistance, etc.

Sleep disturbances caused by high/low blood sugar levels can lead to a problematic cycle of poor sleep and poor blood sugar control.

Your blood sugar levels can have a significant impact on how your body feels and functions. Therefore, stable blood sugar levels can be an important factor in your overall well-being.

With Hello Inside, you can track your blood glucose levels over time with the help of a continuous glucose monitor, allowing you to make decisions that promote your health.

Are you ready to take the first step? First, take our quiz to find out which Hello Inside program is right for you.