Scientists have known that the chance of developing insulin resistance, obesity, and Type 2 diabetes becomes greater with insufficient sleep.
For example, one study from earlier this month indicated that if teenagers increase the amount of sleep they get each night, they may improve their insulin resistance and prevent the future onset of diabetes. While another, from May 2010, suggested that sleep apnea increases insulin resistance due to metabolic changes.
The current study, led by an expert at Cedars-Sinai, is the first to demonstrate a change in metabolic tissue after a person is sleep deprived.
Josiane Broussard, Ph.D., the first author, said:
"For long term health, you have to protect your sleep," said Josiane Broussard, PhD, the study's first author "This study, while small, offers an important clue about the function of sleep and why sleep deprivation leaves us more vulnerable to Type 2 diabetes."
Fat cells need to sleep, too, added Broussard, a fellow at the Cedars-Sinai Diabetes and Obesity Research Institute.
The research, published in Annals of Internal Medicine, not only shows a direct link between insufficient sleep and a disruption of the body's ability to control energy, it also challenges the idea that the main purpose of sleep is to rest the brain, suggesting that sleep also helps regulate the body's metabolism.
In the United States, diabetes is the 7th leading cause of death, and is a serious cause of heart disease and stroke. There are 25.8 million Americans struggling with the disease, and approximately 79 million individuals are prediabetic, according to the CDC (Centers for Disease Control and Prevention).
A small group of healthy adults were observed in the clinical study, which was set out when Broussard was at the University of Chicago, over an eight day period. Four days consisted of 4.5 hours of sleep, and the other four days of 8.5 hours.
Regardless of how much sleep they got, all of the participants consumed the same foods and exercised for the same amount of time. A tissue sample was taken, and analyzed, from each of the subjects after each cycle.
Results showed that after 4 nights of sleep restriction (14 hours of cumulative sleep loss) the healthy subjects' fat tissue samples was significantly more similar to the samples from obese or diabetic people.
The tissue of the volunteers who were sleep deprived was almost 30% less sensitive to insulin, about the same as the shortfall that was seen in diabetic and obese patients' tissue samples compared to those of normal healthy individuals.
In order to help the body process sugars, a hormone known as insulin is produced by the pancreas. When the body does not react as it should to regular insulin levels, it means that the patient is insulin-resistant, which causes the pancreas to create larger amounts of the hormone so that the same amount of sugar can be processed.
The finding came from sleep research specialists and biologists, experts that were pulled together for one of the first times, to analyze metabolism and energy regulation in adipose tissue.
"This eye-opening study helps cement the link between sleep and diabetes, and also suggests that adequate sleep, like diet and exercise, is one of the healthy habits we can adopt to prevent or treat diabetes," said Broussard.
While conducting further research, Broussard hopes to examine how restricting sleep can impact cardiac function, the organs, and blood pressure. The goals of the Cedars-Sinai Diabetes and Obesity Research Institute go along well with her research, revealed Richard Bergman, Ph.D., the institute's director.
"Research like this leads us to a better understanding of what factors make us more susceptible to diabetes, obesity and the conditions that lead to them- and bring us another step closer to being able to better predict, prevent, treat and cure these ailments."