An inconsistent sleep schedule or a general lack of sleep may increase your risk of developing Type 2 diabetes, according to a new study.
Researchers at Brigham and Women’s Hospital in Boston monitored 21 otherwise healthy people, all of whom lived in a lab during the experiment. For three weeks, participants were put on a schedule where they slept for less than six hours per day, and went to sleep later each day— essentially putting them on a 28-hour "day."
The results showed that the participants' abilities to regulate their blood sugar levels became so impaired that they may have developed diabetes had the experiment continued longer, according to the researchers.
"Glucose levels were higher for a longer time, and even rose to prediabetic levels in some participants," wrote the authors in their study, published today (April 11) in the journal Science Translational Medicine.
Poor regulation of blood sugar has been linked with excess weight.
"There's been a lot of interest in the role of sleep restriction or deprivation on obesity and weight gain," said Dr. Vivian Fonseca, chief of endocrinology at Tulane University School of Medicine, who was not involved in the new research.
The new study showed that hormone levels change with lack of sleep, which may help explain how the link works, Fonseca said.
Sleep and blood sugar
In the study, researchers conducted blood tests to measure levels of several hormones, including insulin, cortisol (which is associated with stress), and leptin and ghrelin (which are associated with regulating appetite).
They found that the impaired sleep schedule led to a 32 percent reduction in the amount of insulin released in the body after eating. Insulin is a key hormone in the regulation of blood sugar.
A reduction in insulin levels is one explanation for how sleep disruption or deprivation may lead to diabetes, said Lisa Rafalson, a professor of pediatrics and family medicine at the University at Buffalo.
"Chronic, ongoing sleep deprivation — that's thought to act as kind of an injury to the body over time," Rafalson said.
Elevated stress hormones that keep the body awake can throw off the balance of hormones."Insulin can't do its job efficiently, so you end up getting an overabundance of glucose that remains in the bloodstream," she said.
On the other hand, the new findings cast doubt on another idea — that an increased appetite stemming from sleep loss may also explain the heightened diabetes risk. Researchers have suggested that insufficient sleep leads to higher levels of the hormone ghrelin, which increases appetite, and lower levels of leptin, which signals "fullness," Rafalson said. But in the new study, researchers did not see these changes in hormone levels.
Tired and sick?
"We as a country are sleeping less and less compared to what we used to," said Fonseca, who is also president of medicine and science for the American Diabetes Association.
Researchers need to figure out whether there is a solution to preventing these increases in diabetes risk aside from sleeping more, Fonseca said.
"The reality is a lot of people who are sleep-deprived are sleep-deprived because of the nature of their occupation or work. We need to identify whether there's something else they can do to correct it," he said.
Pass it on: Lack of sleep or irregular sleep patterns may increase your risk of developing Type 2 diabetes.
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