A night of insomnia could tip the body’s metabolism toward fat storage while the muscle is depleted, new research suggests.
Many studies have linked poor sleep, either by insomnia or working on the night shift, with weight gain and health conditions such as type 2 diabetes. But that type of research leaves open the question of whether the loss itself of the dream is the culprit.
A growing number of laboratory studies, focusing on the effects of sleep deprivation, suggest that the answer is “yes.” The new research is added to the evidence.
“We need mechanical studies to understand the effects of sleep loss,” said lead researcher Dr. Jonathan Cedernaes, a research associate at Northwestern University in Chicago.
Cedernaes said studies have shown, for example, that loss of sleep can change a range of markers in the blood, including blood sugar, hormone levels and various byproducts of metabolism.
For the new study, his team explored the effects within adipose and muscle tissue, noting how the activity of genes and protein levels in those tissues changed after a night of insomnia.
The researchers found that in 15 healthy young men, a night of sleep loss caused changes that favored fat storage and muscle breakdown.
“This does not mean that you should be alarmed by a night of loss of sleep,” Cedernaes emphasized. But, he added, the study raises the question of what would happen if poor sleep becomes a regular pattern.
The findings were published online on August 22 in the journal Science Advances.
A sleep researcher who did not participate in the study called the findings “extremely important.”
“The discovery that skeletal muscle proteins decrease and proteins [that increase fat] increase in response to sleep loss is a novel mechanism by which sleep loss can promote obesity and weight gain,” said Josiane Broussard, assistant professor at Colorado State University. , in Fort Collins.
However, with any laboratory study, it is not clear how well artificial conditions reflect real life.
Dr. Eva Szentirmai, an associate professor at Washington State University in Spokane, who studies sleep and metabolism, said: “We do not know if we would see similar changes in specific tissues during the usual loss of long-term sleep, which It is common in our society. ”
In addition, the experiment did not completely capture what it is to work at night, for example.
The volunteers spent two nights in the sleep lab: one night, they could sleep up to 8.5 hours; On the other night, they were kept awake all night, but they had to stay in bed.
The point, explained Cedernaes, was to isolate the metabolic effects of the loss of sleep itself.
But in real life, someone who works the night shift would be physically and mentally active, eating and living during the part of the day when humans normally sleep.
In addition, Szentirmai pointed out, they would be exposed to irregular lighting patterns. And changes in light and eating patterns can directly affect the “muscle protein balance,” he said.
Therefore, he noted, it is possible that night work may be added to the negative effects of loss of sleep in muscles and adipose tissue.
And those who just stay up late and do not get enough sleep? Szentirmai said that studies have shown that these people tend to gain more weight over time, and have a higher risk of obesity, compared to well rested people.
But, he added, those studies do not prove cause and effect.
Cedernaes pointed to the big picture: sleep has a major impact on overall health, and people need to get enough. People vary in how much sleep they need, he said. But, in general, it is recommended that adults receive seven to nine hours each night.
If you work at night and must sleep irregular hours, said Cedernaes, try to be especially attentive to other lifestyle habits, such as eating a healthy diet and exercising regularly.
According to Broussard, research like this could eventually help workers change and others who can not avoid irregular hours of sleep. If researchers understand exactly how sleep disruptions affect the body, he said, they could identify specific ways to counteract those effects.