Why lack of sleep makes you fat


Friday, August 24, 2018

/ dpa

Uppsala A night of sleep resulted in a randomized study Science progress (2018; 4: eaar8590) that the body has stored more fat and reduced muscle protein. In the long term, lack of sleep can lead to overweight, metabolic syndrome and type 2 diabetes.

Epidemiological studies have shown that people with chronic sleep deprivation but also shift workers have an increased risk of obesity or type 2 diabetes. Lack of sleep also hinders the success of the diet. For example, obese subjects lost less weight in a dietary study when their sleep duration was shortened from eight and a half to five and a half hours.


For this reason, a team led by Jonathan Cedernaes of the University of Uppsala has now been examined in a randomized study. They invited 15 healthy volunteers to spend two nights in the lab. During one night, the lights were switched off at 10:30 and the subjects were asked to sleep until 7 a.m. The second night, the subjects also spent in bed, but they were kept awake until the next morning.

On the morning after the two nights, subjects were taken from skeletal muscle and subcutaneous adipose tissue. The studies showed that the lack of sleep in the muscle cells led to a decrease in glycolysis. had.

Thus, the cells consumed less glucose, possibly responsible for the increase in blood sugar levels that occurred in a subsequent oral glucose challenge test. Instead of glucose, muscle cells increasingly resorted to proteins for their energy supply. This catabolic metabolism may have been caused by the increased secretion of glucocorticosteroids from the adrenal glands. The cortisol levels were at least increased after the night was over.

There was an opposite reaction in the fat cells. The glycolysis enzymes were increasingly active. Presumably the fat cells tried to use or store the glucose supplied via the blood: glycolysis supplies the raw material for building fat reserves in the fat cells.

A single sleepless night led to a change in energy metabolism, which in the long run could lead to weight gain and type 2 diabetes. The consequences will not be long. A previous study had shown that five hours of sleep with only four hours of sleep lead to weight gain, in which, in addition to metabolism conversion, the role of sleep-induced increased appetite could also play a role (Sleep 2013, 36: 981-990).

According to Cedernaes, the change in metabolism is caused by a change in DNA methylation. As a result, certain genes are switched on or off. The researchers associate the changes with a delay in the circadian rhythm. In addition, they can demonstrate that skeletal muscles activate genes that promote inflammation.

Chronic inflammation is now being discussed as a trigger for arteriosclerotic changes. The results of the study therefore provide an explanation for the increase in obesity, diabetes and cardiovascular diseases in today's 24/7 society, where sleep is often neglected. © heat / aerzteblatt.de

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