"Sleep duration has shortened considerably in western societies in the past decade and simultaneously, there has been an increase in the prevalence of insulin resistance and type 2 diabetes," said Esther Donga, MD of the Leiden University Medical Center in The Netherlands and lead author of the study. "The co-occurring rises in shortened sleep and diabetes prevalence may not be a coincidence. Our findings show a short night of sleep has more profound effects on metabolic regulation than previously appreciated."
Previous studies have found that reductions in sleep duration over multiple nights result in impaired glucose tolerance, but this is the first study to examine the effects of only a single night of partial sleep restriction on insulin sensitivity.
In this study, researchers examined nine healthy subjects, once after a night of normal sleep duration (approximately eight hours), and once after a night of four hours of sleep. Insulin sensitivity of each study participant was measured using the hyperinsulinemic euglycemic clamp method. This method uses catheters to infuse glucose and insulin into the bloodstream and then determines insulin sensitivity by measuring the amount of glucose necessary to compensate for an increased insulin level without causing hypoglycemia.
"Our data indicate that insulin sensitivity is not fixed in healthy subjects, but depends on the duration of sleep in the preceding night," said Donga. "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."
Donga adds that further studies are needed to evaluate whether interventions aimed at improving sleep duration may be beneficial in stabilizing glucose levels in patients with diabetes.
Other researchers working on the study include: Marieke van Dijk, J. Gert van Dijk, Neinke Biermasz, Gert-Jan Lammers, Klaas van Kralingen, Eleonara Corssmit and Johannes Romijn of Leiden University Medical Center in The Netherlands.