Deep-sleep brain waves at night may influence the body’s sensitivity to insulin, which improves blood sugar management the following day, according to a putative mechanism uncovered in people. The work was published in the “Cell Reports Medicine” publication.
“These synchronised 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,” said Matthew Walker, a professor of neuroscience and psychology at UC Berkeley and the study’s senior author. A rise in the body’s sensitivity to the hormone insulin, which consequently and advantageously decreases blood glucose levels, is predicted by the interaction of two brain waves known as sleep spindles and slow waves.
This is an intriguing development, according to the researchers, since sleep is a changeable lifestyle component that might potentially be employed as a therapeutic and painless supplementary therapy for those with Type 2 diabetes or high blood sugar. In addition to the putative novel mechanistic route, scientists also identified another advantage.
The study’s co-author, Vyoma D. Shah, a researcher at Walker’s Centre for Human Sleep Science, said that the findings “beyond revealing a new mechanism also show that these deep-sleep brain waves could be used as a sensitive marker of someone’s next-day blood sugar levels, more so than traditional sleep metrics.” The results also offer a fresh, non-invasive method — deep sleep brain waves — for mapping and forecasting someone’s blood sugar management, which increases the therapeutic significance of this new discovery.
The team’s research was published in the journal Cell Reports Medicine today. Researchers have been examining how learning and memory performance corresponds to the connection of non-rapid eye movement sleep spindles and deep, slow brain waves for years. In fact, the same group of UC Berkeley researchers earlier discovered that deep sleep brain waves enhanced the hippocampus’ capacity to retain knowledge. The hippocampus is the area of the brain linked with learning.
This current study, however, builds on a mouse study from 2021 and indicates a fresh and hitherto unrecognised significance for these coupled brain waves in humans with regard to the vital physical function of blood sugar regulation. The UC Berkeley researchers initially looked at sleep data from a 600-person sample. Even after adjusting for other variables including age, gender, the quantity and quality of sleep, and deep sleep duration, they discovered that this specific coupled set of brain waves predicted the management of blood sugar the next day.
“This particular coupling of deep-sleep brain waves was more predictive of glucose than an individual’s sleep duration or sleep efficiency,” said Raphael Vallat, a UC Berkeley postdoctoral fellow and research co-author. That suggests that the electrophysiological quality and coordinated dance of these brain oscillations during deep sleep are distinctive in some way.
The scientists then started looking at possible explanations for how deep sleep brain waves may convey a signal down into the body, eventually predicting the control of blood sugar.
The team’s results point to a sequence of events that may assist to understand how and why certain brain waves associated with deep sleep are associated with greater blood sugar regulation. First, they discovered that a transition in the body’s nervous system state into the more tranquil and quiescent branch, known as the parasympathetic nervous system, was predicted by greater and more frequent coupling of the deep-sleep brain waves. They used heart rate variability as a surrogate to quantify the change in the body and the transition to this low-stress state.
The team then focused on the last phase of blood sugar balancing. The scientists also found that this deep sleep switch to the calming branch of the nervous system also predicted an increase in the body’s sensitivity to the hormone insulin, which controls blood sugar levels by telling cells to take up glucose from the bloodstream, preventing a dangerous blood sugar spike.
For those attempting to avoid hyperglycemia and Type 2 diabetes, this is crucial. According to Walker, “there is a series of connected associations in the electrical static of sleep at night, such that deep-sleep brain waves telegraph a recalibration and calming of your nervous system the following day.” This quite wonderful connected calming impact on your neurological system is then linked to a reboot of your body’s sensitivity to insulin, resulting in more efficient blood sugar management the following day.
The same outcomes were then reproduced by the researchers when they looked at a different set of 1,900 people. Walker stated, “I believe we really began to feel more confidence in the conclusions ourselves after we repeated the findings in a new cohort. But given my British suspicion, I won’t start believing in it until others have verified it.