New Study Says This New Method Can Help Manage Even ‘Next-day Blood Sugar Levels’
Scientists have long recognized the correlation between inadequate sleep and an increased risk of diabetes, but the reasoning behind this association has remained elusive—until now.
A team of sleep scientists at the University of California, Berkeley, has revealed an intriguing mechanism. They found that certain deep-sleep brain waves can influence the body’s insulin sensitivity, thereby improving blood sugar control the following day.
“These synchronized brain waves act like a finger that flicks the first domino to start an associated chain reaction from the brain, down to the heart, and then out to alter the body’s regulation of blood sugar,” explained Matthew Walker, a UC Berkeley professor of neuroscience and psychology and the leading author of the new study.
He pointed to a distinctive combination of two types of brain waves, sleep spindles, and slow waves, which predict an enhanced sensitivity to insulin, thereby beneficially lowering blood glucose levels.
This insight paves the way for potential treatments for those battling high blood sugar levels or Type 2 diabetes, leveraging sleep as a modifiable lifestyle factor.
Moreover, the team found these deep-sleep brain waves to be more reliable indicators of next-day blood sugar levels than conventional sleep metrics.
“Adding to the therapeutic relevance of this new discovery, the findings also suggest a novel, non-invasive tool—deep-sleep brain waves—for mapping and predicting someone’s blood sugar control,” shared Vyoma D. Shah, a researcher at Walker’s Center for Human Sleep Science.
Their groundbreaking results were released in the journal Cell Reports Medicine.
Previously, sleep spindles and slow waves during non-rapid eye movement sleep were associated with memory and learning. The same Berkeley researchers had found these deep-sleep waves instrumental in enhancing the hippocampus’s information retention ability. However, the latest research brings to light an entirely new function of these combined waves in regulating blood sugar, building upon a 2021 rodent study.
By examining sleep data from 600 individuals, the researchers found a unique pairing of deep-sleep waves that predicted next-day glucose control, even after accounting for variables such as age, gender, sleep duration, and quality.
Raphael Vallat, a UC Berkeley postdoctoral fellow, noted, “This particular coupling of deep-sleep brain waves was more predictive of glucose than an individual’s sleep duration or sleep efficiency. That indicates there is something uniquely special about the electrophysiological quality and coordinated ballet of these brain oscillations during deep sleep.”
The team then investigated how these deep-sleep waves influence the body’s blood glucose regulation. The study revealed a sequential series of associations, beginning with frequent deep-sleep waves that predict a switch to a more restful state of the nervous system, the parasympathetic nervous system.
The team’s findings revealed a cascade of events that could explain the correlation between these deep-sleep brain waves and superior blood sugar control. They discovered that stronger and more frequent synchronizations of these deep-sleep brain waves anticipated a shift in the body’s nervous system to the more restful parasympathetic nervous system. This shift to a low-stress state was gauged using heart rate variability as a proxy.
The team then focused on the final step of blood sugar balance, discovering that this deep sleep-induced shift to the tranquil branch of the nervous system further anticipated heightened insulin sensitivity in the body. This improved responsiveness to insulin, which facilitates glucose absorption from the bloodstream, is crucial for people seeking to avoid hyperglycemia and Type 2 diabetes.
“In the electrical static of sleep at night, there is a series of connected associations, such that deep-sleep brain waves telegraph a recalibration and calming of your nervous system the following day,” Walker commented. “This rather marvelous associated soothing effect on your nervous system is then associated with a reboot of your body’s sensitivity to insulin, resulting in a more effective control of blood sugar the next day.”
The researchers further substantiated these effects by examining an additional group of 1,900 participants.
After they replicated the findings in a different group, “I think we actually started to feel more confident in the results ourselves,” said Walker.
“But I’ll wait for others to replicate it before I truly start believing, such is my British skepticism.”
The researchers underscored the potential long-term clinical implications of their findings. Current diabetes treatments can be challenging for patients to maintain, as can the recommended lifestyle modifications like dietary adjustments and regular physical activity.
Sleep, on the other hand, is an overwhelmingly benign experience for most individuals. Although it may not be a standalone solution, the possibility of developing new technologies that safely adjust brain waves during deep sleep—as uncovered by this research—may aid individuals in better managing their blood sugar. According to the research team, this is cause for optimism.
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