How lack of sleep could lead to type 2 diabetes
A first study helps explain why sleep is so important for curbing obesity and type 2 diabetes. Researchers have uncovered how lack of sleep leads to metabolic problems.
Past studies have linked sleep disorders to weight gain and diabetes but why it happens has been somewhat of a mystery. Esra Tasali, MD, assistant professor of medicine at the University of Chicago and senior author of the study said in a press release, "Experimental laboratory studies, like ours, help us unravel the mechanisms that may be responsible."
Lack of sleep releases fatty acids
Researchers for the study found getting too little sleep was associated with a 15 to 30 percent increase in the amount of free fatty acids circulating in the body late and night and early in the morning. Elevated fatty acids that were measured with blood tests correlated with increased insulin resistance that precedes diabetes.
Josiane Broussard, PhD, a former graduate student at the University of Chicago who lead the study said getting less sleep affects levels of circulating growth hormone and noradrenaine, which in turn can increase circulating fatty acids.
The researchers enrolled 19 healthy males for the study whose blood levels of free fatty acids, growth hormone, blood sugar and insulin, in addition to the stress hormones noradrenaline and cortisol were measured every 15 to 30 minutes over a 24 hour period.
In one scenario the study participants averaged 7.8 hours of sleep each night. In the other, they averaged just over 4 hours of sleep a night. The two studies were spaced four weeks apart. All of the men's diets were strictly controlled. Glucose tolerance tests were also performed after four-nights of each scenario.
The authors noted that a shorter night's sleep reduced insulin's ability to regulate glucose by twenty-three percent, producing a state of insulin resistance like that seen in the early stages of diabetes.
Fatty acids are important for energy production especially during exercise. A constant elevation of lipids in the bloodstream are normally seen among diabetics and in the presence of obesity.
The study suggests lack of sleep disrupts a crucial metabolic pathway that leads to obesity and type 2 diabetes. In a commentary to the study, published February 19, 2015, in Diabetologia, Jonathan Jun, MD, and Vsevolod Polotsky, MD, PhD, of Johns Hopkins University School of Medicine query "...why don't clinicians routinely ask their patients about sleep?"