Losing a single night’s sleep may affect the liver’s ability to produce glucose and process insulin, increasing the risk of metabolic diseases such as fatty liver and Type 2 diabetes.
It’s been known that being deprived of sleep is associated with eating more, moving less and having a higher risk of developing Type 2 diabetes.
However, it’s is not clear whether glucose intolerance was due to the changes in food intake or energy expenditure or to the sleep deprivation itself.
Now, according to researchers at Toho University Graduate School of Medicine in Japan., their most recent study suggests that glucose intolerance is due to sleep deprivation.
How Was the Study Conducted?
The researchers studied two groups of mice: One group was kept awake for six hours each night, the sleep-deprived group, while the control group was allowed to sleep as desired.
The research team offered unlimited high-fat food and sugar water–mimicking lifestyle-related food choices that people make–to both groups prior to the study. During the sleep/wake period, the animals had limited opportunity for physical activity.
The researchers measured glucose levels and fat content of the liver immediately after the trial period. Blood glucose levels were significantly higher in the sleep deprivation group than controls after one six-hour session of wakefulness.
Triglyceride (fat) levels and the production of glucose in the liver also increased in the sleep deprivation group after a single wake period.
Elevated liver triglycerides are associated with insulin resistance, or the inability of the body to process insulin properly.
What Do the Results Mean?
The researchers also found that lack of sleep changed the expression of enzymes that regulate metabolism in the liver in the sleep deprivation group.
“This study implies that glucose intolerance can be induced by only single 6 hours sleep deprivation,” says Dr. Naoki Kumashiro, “and hepatic steatosis and hepatic insulin resistance may be the key target to cancel the glucose intolerance by sleep deprivation.”
He says although it is difficult to resolve sleep deprivation itself, drugs targeting Elovl3 or other enzymes found in this study may become a breakthrough in understanding sleep deprivation induced hepatic steatosis and glucose intolerance.
These findings suggest that intervention studies designed to prevent sleep deprivation should be performed in the future, according to a press release.
Kumashiro says the intervention studies targeting hepatic Elovl3 is ongoing in mice. “If this will succeed,” tells dLife, “this intervention may be applied into humans in the future.”
Source: American Physiological Society.
The findings are published ahead of print in the American Journal of Physiology–Endocrinology and Metabolism.