Studies show that people with chronic insomnia and shift work may have an increased risk of obesity and type 2 diabetes. Finnish scientists have examined this relationship from the point of view of metabolic mechanisms.
Just one late night causes the body to store fat more intensively and causes a loss of muscle tissue. The effect is multiplied as the sleep deficit becomes chronic. People suffering from sleep disorders are more at risk of obesity, so they have an increased risk of developing the so-called metabolic syndrome and developing type 2 diabetes. Sleep deficit also hampers weight reduction - people who are overweight and obese, who sleep too little, despite taking weight reduction measures, lose less weight than those who get enough sleep.
Finnish experiment
A team of Finnish scientists from Uppsala University, led by Dr. Jonathan Cedernaes, conducted an experiment to decipher the metabolic mechanism of this phenomenon. The study involved 15 he althy volunteers who were to spend two nights in a sleep lab. During the first night, the lights were turned off at 10.30 p.m. and the subjects were to sleep until 7 a.m. The volunteers also spent the second night in bed, but were not allowed to sleep until morning. In the morning, samples of muscle and subcutaneous fat were taken from them. It turned out that after a sleepless night in muscle cells, the process of glycolysis (conversion of glucose into energy) was much less intense. The cells used less glucose, which led to an increase in glucose levels in the blood. Instead of making energy from glucose, cells burn proteins from the muscles.
The reason was probably the insomnia-induced discharge of glucocorticoids produced by the adrenal glands - after a sleepless night, the level of cortisol in the blood of the volunteers was clearly elevated. On the other hand, the opposite process took place in fat cells - excessive activation of glycolysis enzymes. Fat cells tried to use up - that is, to store - the excess glucose supplied in the blood, creating more stores of fat.
So already one sleepless night caused the metabolic processes to shift. In the long run, this can lead to weight gain and the development of type 2 diabetes.hours, weight gain occurs. Also, caused by lack of sleep, increased appetite may be of importance.
Sleep deficit and civilization diseases
Scientists speculate that disturbance of the sleep-wake rhythm causes disturbance of DNA methylation, which in turn induces an alteration of metabolic processes. Methylation is a biochemical process that activates (or deactivates) genes so that they can perform various functions.
Researchers have also shown that due to methylation disorders, genes in skeletal muscles are activated, which increase the propensity for inflammatory processes - chronic inflammation is one of the main factors causing atherosclerotic changes.
So the lack of sleep, symptomatic of Western civilization, could explain the growing epidemics of obesity, diabetes and cardiovascular disease.
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