How deep sleep brain waves can affect blood sugar levels

Summary: Brain waves in deep sleep may be a major factor in blood sugar regulation. The research shows that a combination of sleep spindles and slow waves can predict an increase in insulin sensitivity and subsequently lower glucose levels.

This discovery highlights sleep as a potential lifestyle adjustment to improve blood sugar control and manage diabetes. Furthermore, these brain waves during deep sleep could also be used to predict a person’s glucose levels the next day, proving more accurate than traditional sleep measurements.

Key Facts:

1. The research suggests that the coupling of brain waves in deep sleep, specifically sleep spindles and slow waves, may predict an increase in insulin sensitivity and therefore improve glucose control.
2. Brain waves during deep sleep could potentially be used as a reliable predictor of next-day blood glucose levels, offering a new, non-invasive tool for managing glucose control.
3. The study found that this particular set of deep sleep brain waves predicted next-day glucose control more effectively than factors such as sleep duration or sleep efficiency.

Source: UC Berkeley

Researchers have known that a lack of quality sleep can increase a person’s risk of diabetes. What has remained a mystery, however, is why.

Now, new findings from a team of sleep researchers at the University of California, Berkeley, are closer to an answer.

Researchers have uncovered a potential mechanism in humans that explains how and why brain waves during deep sleep at night are able to regulate the body’s sensitivity to insulin, which in turn improves blood sugar control the next day.

“These synchronized brain waves act like a finger flicking the first domino to start an associated chain reaction from the brain, down to the heart and then out to change the body’s regulation of blood sugar,” said Matthew Walker, a UC Berkeley professor of neuroscience and psychology. and senior author of the new study.

“In particular, the combination of two brain waves, called sleep spindles and slow waves, predicts an increase in the body’s sensitivity to the hormone called insulin, which consequently and beneficially lowers blood sugar levels.”

The researchers say this is an exciting advance because sleep is a modifiable lifestyle factor that can now be used as part of a therapeutic and painless adjunctive treatment for those with high blood sugar or type 2 diabetes.

Researchers also noted an additional benefit beyond the potential new mechanistic pathway.

“In addition to revealing a new mechanism, our results also show that these deep sleep brain waves can be used as a sensitive marker of a person’s blood sugar levels the next day, more so than traditional sleep measurements,” said Vyoma D. Shah, a researcher. at the Walker’s Center for Human Sleep Science and co-author of the study.

“To add to the therapeutic relevance of this new discovery, the findings also suggest a new, non-invasive tool—brain waves during deep sleep—to map and predict a person’s blood sugar control.”

The team’s results were published today in the journal Cell Reports Medicine.

For years, researchers have studied how the coupling of non-rapid eye movement sleep spindles and deep, slow brain waves corresponded to an entirely different function – learning and memory.

In fact, the same team of UC Berkeley researchers previously found that brain waves during deep sleep enhanced the ability of the hippocampus—the part of the brain associated with learning—to retain information.

But this new research builds on a 2021 rodent study and reveals a new and previously unrecognized role for these combined brain waves in humans when it comes to the critical bodily function of blood sugar control.

The UC Berkeley researchers first examined sleep data in a group of 600 people. They found that this particular coupled set of brain waves during deep sleep predicted glucose control the next day, even after controlling for other factors such as age, sex, and the duration and quality of sleep.

“This particular coupling of brain waves in deep sleep was more predictive of glucose than a person’s sleep duration or sleep efficiency,” said Raphael Vallat, a UC Berkeley postdoctoral fellow and co-author of the study.

“It indicates that there is something very special about the electrophysiological quality and coordinated ballet of these brain oscillations during deep sleep.”

Next, the team then set out to explore the descending pathway that could explain the connection between these deep sleep brain waves that send a signal down the body and ultimately predict the regulation of blood sugar.

The team’s findings reveal a set of unfolding steps that may help explain how and why these deep sleep brain waves are related to superior blood sugar control.

First, they found that stronger and more frequent coupling of the brain waves in deep sleep predicted a shift in the state of the body’s nervous system to the quieter, more calming branch, called the parasympathetic nervous system.

They measured this change in the body and the shift to this low-stress state by using heart rate variability as a proxy.

Next, the team turned their attention to the final step in blood sugar balance.

The researchers further discovered that this deep sleep shift to the calming branch of the nervous system further predicted an increased sensitivity of the body to the glucose-regulating hormone called insulin, which instructs cells to absorb glucose from the bloodstream, preventing a harmful rise in blood sugar. .

It is especially important for people trying to reverse hyperglycemia and type 2 diabetes.

“In the electrical static of sleep at night, there are a series of linked associations, such that deep sleep brain waves telegraph a recalibration and calming of your nervous system the following day,” Walker said.

“This quite wonderful associated calming effect on your nervous system is then associated with a re-start of your body’s sensitivity to insulin, resulting in more effective control of blood sugar the next day.”

The researchers subsequently replicated the same effects by examining a separate group of 1,900 participants.

“Once we replicated the results in another cohort, I think we actually started to feel more confident about the results themselves,” Walker said. “But I’ll wait for others to replicate it before I really start to believe, such is my British skepticism.”

The researchers said the research is particularly exciting given the potential clinical significance years ahead. Diabetes treatments already on the market can sometimes be difficult for patients to adhere to. The same applies to the recommended lifestyle changes, including different eating habits and regular exercise.

However, sleep is a largely painless experience for most people.

And while sleep won’t be the only magic bullet, the prospect of new technologies that can safely alter brain waves during deep sleep, as this new research has revealed, could help people better manage their blood sugar. That, the research team said, is reason for hope.

About this sleep research news

Author: Jason Pohl
Source: UC Berkeley
Contact: Jason Pohl – UC Berkeley
Image: Image credited to Neuroscience News

Original research: Open access.
“Coordinated human sleeping brain waves map peripheral body glucose homeostasis” by Matthew Walker et al. Cell Reports Medicine

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Abstract

Coordinated human sleeping brain waves map peripheral body glucose homeostasis

Highlights

• Coupled NREM sleep brain waves predict superior next-day glucose control in two cohorts
• This sleep-glucose connection is partially mediated by autonomic activity
• Sleep can regulate glycemic status selectively via insulin sensitivity
• Thus, NREM brain waves offer a glycemic biomarker and a potential therapeutic target

Summary

Inadequate sleep impairs glucose regulation, increasing the risk of diabetes. However, what it is about the human sleeping brain that regulates blood sugar is still unknown.

In a study of over 600 people, we demonstrate that the coupling of non-rapid eye movement (NREM) sleep spindles and slow oscillations the night before is associated with improved peripheral glucose control the next day.

We further show that this sleep-associated glucose pathway can affect glycemic status through altered insulin sensitivity rather than through altered pancreatic beta-cell function. Furthermore, we replicate these associations in an independent dataset of over 1,900 adults.

Of therapeutic importance, the coupling between slow oscillations and spindles was the most significant sleep predictor of next-day fasting glucose, even more so than traditional sleep markers, relevant to the possibility of an electroencephalogram (EEG) index of hyperglycemia.

Together, these findings describe a sleep-brain-body framework of optimal human glucose homeostasis that offers a potential prognostic sleep signature for glycemic control.