Two nights of good sleep appeared to reverse the negative metabolic effects that can come with short-term sleep deprivation, according to a new study.

Researchers took 19 participants, all of them "lean" young men, and restricted their sleep to only 4.5 hours in bed for four consecutive nights. The participants were then allowed two consecutive nights of 12 hours in bed on the first night and 10 hours on the second night.

Insulin sensitivity was reduced by 23% after sleep restriction compared to normal sleep (at about 8 hours a night), but gained about half of that reduction back after sleep recovery, according to Josiane Broussard, PhD, at the University of Colorado Boulder, and colleagues.

"A common question is whether, and how quickly, an individual can recover from the adverse effects of sleep loss on glucose homeostasis. We have demonstrated that 2 nights of recovery sleep averaging nearly 10 hours per night following 4 nights of sleep restriction in healthy young lean men is sufficient to improve insulin sensitivity," they wrote in Diabetes Care.



Acute insulin response to glucose did not differ between any of the sleep conditions, they reported, and disposition index -- a measure of insulin sensitivity multiplied by acute insulin response to glucose -- was reduced by 16% after sleep restriction when compared with normal sleep, but returned to normal after recovery sleep.

"The metabolic response to this extra sleep was very interesting and encouraging," said co-author, Esra Tasali, MD, of the University of Chicago, in a press release. "It shows that young, healthy people who sporadically fail to get sufficient sleep during the work week can reduce their diabetes risk if they catch up on sleep during the weekend."

Participants received standardized meals 24 hours to each intravenous glucose tolerance test, which was done after the normal, restricted, and recovery sleep sessions. Researchers tracked the normal sleeping habits of the participants prior to the study and found that they slept an average of 7.8 hours. During sleep restriction, they slept 4.3 hours, and during sleep recovery 9.7 hours. Weight was measured prior to each intravenous glucose tolerance test and was similar between sleep conditions.

"This data is clinically relevant because such sleep patterns (i.e., short-term sleep restriction on workdays and recovery sleep on weekends) are quite common in modern society," the authors wrote.

Limitations of the study include the laboratory setting, which may not reflect the real world conditions, and its relatively short duration.

"Future studies in real-world settings are needed to investigate whether catching up on sleep could be an effective behavioral intervention in the prevention and management of type 2 diabetes," Broussard's group concluded.