The link between diabetes and poor sleep quality has already been established, but new research digs a little deeper into that association and helps explain why sleep loss may lead to an increased risk of diabetes.
The study, published in the journal of the European Association for the Study of Diabetes, Diabetologia, found that sleep deprivation could increase the levels of free fatty acids in the blood, as well as cause temporary pre-diabetic conditions in healthy young men. The study claims to be the first to analyze how sleep impacts 24-hour fatty acid levels in the blood, and finds that lack of sleep can disrupt fat metabolism, impairing insulin’s ability to regulate blood sugar.
“At the population level, multiple studies have reported connections between restricted sleep, weight gain, and type 2 diabetes,” Dr. Esra Tasali, assistant professor of medicine at the University of Chicago and senior author of the study, said in the press release. “Experimental laboratory studies, like ours, help us unravel the mechanisms that may be responsible.”
Sleep deprivation is a common problem in the modern world — especially among people who are highly stressed, or are struggling with insomnia or depression. While many factors are involved in people developing obesity (such as poor diet, lack of physical activity, and genetic predisposition), lack of sleep can also increase a person’s risk for obesity.
In the study, the researchers found that when the 19 male participants got only four hours of sleep for three nights, their blood levels of fatty acids remained high from 4 a.m. to 9 a.m. During the period of time that the fatty acid levels were high, insulin’s efficacy was reduced. They compared that to the participants spending 8.5 hours in bed over the course of four nights. They measured their levels of free fatty acids, glucose, insulin, and the stress hormones noradrenaline and cortisol.
Overall, they found that lack of sleep caused a 15-30 percent increase in late night and early morning fatty acid levels, which correlated with a rise in insulin resistance, which is a sign of pre-diabetes. This lasted five hours.
“It definitely looks like a packaged deal,” Josiane Broussard, a former graduate student at the University of Chicago and the lead author of the study, said in the press release. “Curtailed sleep produced marked changes in the secretion of growth hormone and levels of noradrenaline — which can increase circulating fatty acids. The result was a significant loss of the benefits of insulin. This crucial hormone was less able to do its job. Insulin action in these healthy young men resembled what we typically see in early stages of diabetes.”