Slow Wave Sleep and risk of type 2 diabetes

Interesting study.

Randy



Slow-wave sleep and the risk of type 2 diabetes in humans

Esra Tasali*, Rachel Leproult, David A. Ehrmann, and Eve Van Cauter

Department of Medicine, University of Chicago, Chicago, IL 60637

Edited by Donald F. Steiner, University of Chicago, Chicago, IL, and
approved November 9, 2007 (received for review July 10, 2007)


There is convincing evidence that, in humans, discrete sleep stages
are important for daytime brain function, but whether any particular
sleep stage has functional significance for the rest of the body is
not known. Deep non-rapid eye movement (NREM) sleep, also known as
slow-wave sleep (SWS), is thought to be the most "restorative" sleep
stage, but beneficial effects of SWS for physical well being have not
been demonstrated. The initiation of SWS coincides with hormonal
changes that affect glucose regulation, suggesting that SWS may be
important for normal glucose tolerance. If this were so, selective
suppression of SWS should adversely affect glucose homeostasis and
increase the risk of type 2 diabetes. Here we show that, in young
healthy adults, all-night selective suppression of SWS, without any
change in total sleep time, results in marked decreases in insulin
sensitivity without adequate compensatory increase in insulin release,
leading to reduced glucose tolerance and increased diabetes risk. SWS
suppression reduced delta spectral power, the dominant EEG frequency
range in SWS, and left other EEG frequency bands unchanged.
Importantly, the magnitude of the decrease in insulin sensitivity was
strongly correlated with the magnitude of the reduction in SWS. These
findings demonstrate a clear role for SWS in the maintenance of normal
glucose homeostasis. Furthermore, our data suggest that reduced sleep
quality with low levels of SWS, as occurs in aging and in many obese
individuals, may contribute to increase the risk of type 2 diabetes.