Sleep Deprivation and Insulin Resistance: How Poor Sleep Affects Blood Sugar

Woman lying down with arms crossed over stomach.

In the last year, I have had 2 instances of high levels of stress that affected both my sleep and blood sugar levels, in particular my fasting blood sugar, as that is what I check at home. While diet plays a key role in managing insulin resistance and blood sugar levels, addressing sleep deprivation is also just as crucial.

We all have stress in our lives, but when it starts to affect our sleep, that is when things get really messed up. The ability to sleep is so healing and restorative for the body, and an inability to sleep deeply immediately affects my fasting blood sugar.

Getting at least 7 hours of sleep per night is recommended to maintain health and well-being, yet many people do not get adequate sleep and suffer from sleep deprivation. The stress of modern day living is a contributing factor to poor sleep, which is associated with increased insulin resistance.

I know through tracking my blood sugar that both sleep deprivation and anger can affect my blood sugar levels. We can be doing everything right dietarily, but if we are running around angry and stressed out, it can be challenging to maintain normal, healthy blood sugar levels.

Addressing the emotions and life factors contributing to sleep deprivation is a key component to keeping your blood sugar levels within optimal ranges. The rise in cortisol, which signals the release of glucose into the bloodstream so you can run from the tiger, whether it is fake or real, is affecting both your sleep and blood sugar levels.

A 2022 systematic review of 10 studies found that short sleep duration was significantly associated with insulin resistance and an increased risk of metabolic dysfunction. It is thought that increased levels of inflammatory markers, such as C-reactive protein, may be linked to how the loss of sleep can lead to prediabetes.

In one study from the review, people with prediabetes were more likely to report poor sleep quality than those with normal blood sugar levels. Sleep loss may also affect blood sugar regulation through other pathways.

Research suggests that inadequate sleep can alter hormones involved in glucose metabolism, impair the body’s response to insulin, disrupt fatty acid metabolism, increase cortisol levels, and interfere with the body’s natural circadian rhythm. Together, these changes may make it harder for cells to respond properly to insulin and maintain healthy blood sugar levels.

Sleep Deprivation and Inflammation

In one study included in the review, people with prediabetes were more likely to report poor sleep quality than those with normal blood sugar levels. These people with prediabetes also had higher levels of C-reactive protein, suggesting that inflammation may be one mechanism linking inadequate sleep to insulin resistance and prediabetes.

Poor Sleep and Increased Cortisol

A study found that acute total sleep deprivation increased cortisol levels, one of the body’s primary stress hormones. Cortisol helps mobilize energy during times of stress by stimulating the release of stored glucose into the bloodstream. This response can be helpful in short-term stress situations, but chronically elevated cortisol levels may contribute to higher blood sugar levels and impaired glucose control.

Circadian Rhythm and Insulin Resistance

Disrupted circadian rhythms may be another link between poor sleep and insulin resistance. When the body’s internal clock is out of sync, insulin sensitivity decreases, making it harder for cells to respond properly to insulin and regulate blood sugar levels.

While more research is needed to fully understand the mechanisms involved, the overall findings suggest that getting enough quality sleep is an important part of maintaining insulin sensitivity and reducing the risk of prediabetes.

In another small study of 9 healthy adults, just one night of sleep deprivation reduced insulin sensitivity. Participants who slept 4 hours instead of 7.5 hours had worse glucose control the following day. Some key findings from this study are:

The liver became more resistant to insulin, causing it to release more glucose into the bloodstream.
Muscle and other tissues were less responsive to insulin and took up less glucose from the blood.
Sleep restriction increased circulating fatty acids, which are associated with insulin resistance.
The amount of glucose needed to maintain normal blood sugar levels decreased by about 25%, indicating a significant reduction in insulin sensitivity.

Just one night of partial sleep deprivation reduced insulin sensitivity and increased insulin resistance, resulting in poorer glucose control the following day. A night of inadequate sleep can impair multiple aspects of glucose metabolism, making the body less effective at moving glucose out of the bloodstream and into cells.

Sleep Restriction Versus 24 Hours of Sleep Deprivation

Another interesting study found that getting only 4 hours of sleep for four nights in a row was worse for insulin resistance than staying awake for one full 24-hour period. In this study, the researchers divided 28 healthy men into two groups to compare one night of total sleep deprivation (24 hours awake) vs 4 nights of sleep restriction of sleeping only 4 hours per night (1 am to 5 am)

They then measured blood sugar, insulin, cortisol, and markers of insulin sensitivity using a glucose tolerance test and found that 4 nights of sleeping for only 4 hours was worse than 1 night without sleep. After 4 nights of restricted sleep, the body needed more insulin to manage blood sugar, as cells were less responsive to it and fasting insulin levels were higher.

Even when blood sugar levels remain normal, sleep restriction may cause the pancreas to produce more insulin to keep blood sugar under control. This study found that just four nights of sleeping only four hours per night increased insulin resistance, suggesting that even short periods of inadequate sleep can negatively affect metabolism.

4 nights of short sleep are likely more harmful than 1 night of no sleep, as long as regular sleep cycles are restored. Consistently getting enough sleep appears to be very important for maintaining insulin sensitivity.

The study suggests that four nights of short sleep may be more harmful than a single night without sleep, provided normal sleep patterns are restored afterward. Consistently getting enough sleep appears to play an important role in maintaining healthy insulin sensitivity.

While diet, exercise, and maintaining a healthy liver and weight are important for blood sugar control, sleep is a piece of the puzzle that is often overlooked. The research suggests that even a few nights of inadequate sleep can increase insulin resistance, raise cortisol levels, and make it harder for the body to regulate blood sugar effectively.

I know from tracking my own fasting blood sugar that periods of stress and poor sleep can have a noticeable impact, even when my diet remains the same. It is important to identify the stressors in our lives contributing to poor sleep and make whatever changes are possible.

Prioritizing sleep and addressing the factors that interfere with it will not only make you feel so much better after a good night’s sleep but can also support healthy insulin sensitivity and metabolic health.

If you are struggling with elevated blood sugar levels or insulin resistance, it may be worth looking beyond your diet and considering whether sleep quality and sleep duration could be playing a role. Small improvements in sleep habits may have benefits that extend far beyond simply feeling more rested.

While these are sleeping tips that help me sleep better, sometimes, when stress is the cause, we need more help. If you are having trouble sleeping, reach out to someone who may be able to help.

Improving sleep can have a powerful impact on blood sugar regulation, but it is only one part of the picture. Learn more about the foods and nutrition strategies for an insulin resistance diet.