Did you know that 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 hepatic steatosis (fatty liver) and type 2 diabetes?
Sleep deprivation has been associated with eating more, moving less and having a higher risk of developing type 2 diabetes. However, a team of researchers from Toho University Graduate School of Medicine in Japan wanted to know more, since “it was not clear whether glucose intolerance was due to the changes in food intake or energy expenditure or to the sleep deprivation itself.”
The researchers studied two groups of mice: One group was kept awake for 6 hours each night (“sleep deprivation”), while the control group was allowed to sleep as desired. Before the intervention, the research team offered both groups unlimited high-fat food and sugar water—mimicking lifestyle-related food choices that people make. During the sleep/wake period, the animals had limited opportunity for physical activity.
The scientists measured glucose levels and fat content in the liver immediately after the trial period. Blood glucose levels were significantly higher in the sleep deprivation group than in the controls after one 6-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.
In addition, lack of sleep changed the expression of enzymes that regulate metabolism in the liver in the sleep deprivation group. These findings suggest that “intervention studies designed to prevent sleep deprivation–induced hepatic steatosis and insulin resistance should be performed in the future,” the researchers wrote.
Read the full article, “Mechanisms of sleep deprivation-induced hepatic steatosis and insulin resistance in mice,” in the September 2018 American Journal of Physiology—Endocrinology and Metabolism.