Adult-onset diabetes (type 2) has been linked to poor diet and lack of exercise. But recent studies have implicated lack of sleep as a major factor in the disease. Earlier this year, U.S. researchers reported that people who slept less than six hours a night were 4.5 times more likely to develop symptoms of diabetes than people who slept longer.
But the latest study, conducted by Leiden University Medical Center in the Netherlands, shows how just one late night can affect the body’s ability to use insulin the next day. They examined nine healthy people, once after eight hours of sleep and the second time, after four hours of sleep.
Results of the study, published in the Journal of Clinical Endocrinology & Metabolism, showed that just one night of short sleep (4 hours) reduced insulin sensitivity by 19 to 25 percent.
“Our data indicate that insulin sensitivity is not fixed in healthy (people), but depends on the duration of sleep in the preceding night,” Ester Donga, Director of the Leiden University Medical Center wrote in the study. “In fact it is tempting to speculate that the negative effects of multiple nights of shortened sleep on glucose tolerance can be reproduced, at least in part, by just one sleepless night.”
Insulin is a hormone produced by the pancreas that controls the body’s use of glucose sugar. When insulin sensitivity levels go down, the pancreas produces more insulin, which causes sugar levels to rise in the body. Over time, high sugar levels can lead to damage of the kidneys, heart, nerves, and major arteries. Damage to the ocular nerves is common.
Further studies, Donga indicated, are needed to determine if improving sleep could help stabilize insulin sensitivity in adults.
Experts recommend 7 to 9 hours of sleep for adults.