Fat cells have difficulty responding to insulin, the hormone responsible for regulating blood sugar levels, when you’re sleep deprived, according to a new study by researchers at the University of Chicago. As a result, the metabolism of fat cells slows down considerably. The findings add to a growing body of evidence establishing a link between lack of sleep fat metabolism, and body weight, including a recent study showing that sleep deprivation inhibits fat burning and increases muscle loss.
The results may not be entirely surprising, however, as the benefits of getting a good night’s sleep seem to be nearly endless. In addition to simply making a person feel rested a ready for the day, getting consistent sleep has mental health benefits and can potentially lower the risk for heart disease. Sleep also plays an important role in immune functions and preventing infections.
A Small but Solid Study
In order to conduct their study, associate medicine professor Matthew Brady and a team of other researchers studies seven individuals, including a single woman and six men, for four nights. The subjects had an average age of 24, and all were healthy and of a normal body weight. All seven of the subjects experienced a reduction in insulin sensitivity after getting only 4.5 hours of sleep each night during the study period.
According to Brady, the reduced insulin sensitivity made the metabolism of subjects similar to that of a 34 or even 44-year-old individual rather than a 24-year-old one. His interpretation of the findings is that prolonged, continual sleep deprivation would increase an individual’s risk of developing a metabolic disease such as diabetes or obesity.
In order to measure insulin sensitivity, the researchers tested the subjects’ blood using intravenous glucose tolerance tests. They also extracted abdominal fat to test its insulin sensitivity. Measurements were taken after the participants had slept normally for eight hours each night, and again after being subjected to the study conditions.
The average participant in the study experienced a 16% reduction in insulin sensitivity over the course of the study. REM sleep, which is a necessary component of a healthy sleep cycle, was also cut in half while the participants slept for only 4.5 hours per night.
Does Laboratory Sleep Deprivation Reflect Real-Life Conditions?
According to Lilian de Jonge of the National Institues of Health, the reduction in insulin sensitivity observed in the study may have plenty to do with the quality of sleep, not just the lack of it. She said that study participants never sleep as well in an unfamiliar hospital bed as they do at home, particularly when they’re hooked up to measuring devices and other uncomfortable implements.
She also said that people who are sleep deprived in the real world usually get approximately five to six hours of sleep each night for prolonged periods of time. A person’s metabolism may eventually adjust to continuous sleep deprivation, according to de Jonge.
In the future, the researchers will examine how changes in sleeping patterns can help obese individuals lose weight.
The Bottom Line
Sleep deprivation could lower your body’s insulin sensitivity by up to 16%, according to a recent study by the University of Chicago. This, in turn, reduces fat metabolism and inhibits fat burning.
The full text of the study is available online in the medical journal Annal of Internal Medicine.