Sleep experts have known for years that sleep is an essential support for brain function.  The effects of sleep deprivation like trouble concentrating and difficulties with decision making show that when we don’t get enough sleep, our brains don’t work as well as they do when we are well rested.  But new research into the effects of sleep deprivation indicates that sleep does more than just let our brain rest.

A new study conducted by the University of Chicago School of Medicine and published in the Annals of Internal Medicine shows that there is also a strong link between sleep and energy regulation.  The research team found that sleep deprivation reduces the ability of fat cells to respond to insulin by as much as 30%.  Overtime, this can have serious health consequences.

The study was the brainchild of Josiane Broussard, a PhD candidate in sleep research who wanted to look at the relationship between sleep and metabolism at a molecular level.  She pulled together experts in sleep science, diabetes, and energy regulation to study the effect of sleep on fat cells.  The team focused their research on fat cells because of their relationship with metabolism, weight, and energy regulation.

Most of us think of fat cells as something bad that we would like to get rid of but these cells play an important role in our biology.  Our fat cells have a very important job.  They are responsible for storing excess energy and then releasing that energy when our body needs it.  Insulin plays a key role in our energy regulation and when our bodies and our fat cells don’t respond properly to it, it causes problems.

Previous research has established a link between sleep deprivation and an increased risk of developing diabetes.  This study sought to further cement that link and to gain a better understanding of why the risk increases by looking what was happening at a molecular level when people don’t get the sleep they need.  The study included 7 young, healthy participants, 6 male and 1 female.  All participants followed the same protocols over the length of the study including a tightly controlled diet.  The study was split into two sections which were conducted with at least 4 weeks between them.

During the first section, all participants slept for 8.5 hours each night for four consecutive nights.  On the morning following the fourth night of sleep, each participant was given an intravenous glucose tolerance test which measures how sensitive the body is to insulin.  A tissue biopsy was also taken from the abdomen of each participant in order for the research team to measure how their fat cells responded to insulin.

The same protocol was followed during the second section with only one difference; participants were only allowed to sleep for 4.5 hours on each of the four nights.

What the team found was surprising.  After four nights of sleep deprivation, the average total-body insulin response decreased by 16% on average and the fat cells insulin sensitivity decreased by 30%.  These numbers are pretty significant in their own right but are even more telling when you look a little deeper.  The reduction in response and sensitivity seen in the lean, healthy participants was similar to those seen in people who are obese and those with diabetes.   Even more shocking was that when the participants were sleep deprived, it took three times as much insulin to achieve even half the insulin response seen when they were not.

These findings suggest that the role sleep plays in our metabolism and our body’s ability to regulate energy may be even more important than the role it plays in supporting brain function.  While the size of the study was too small to provide conclusive results, it opens the door to new avenues of research that may unlock new preventative measures and treatment options for obesity and diabetes.


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