Slow-wave sleep and the risk of type 2 diabetes in humans
2.1.2008 University of Chicago
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.
Diabetes Mellitus Type 2 (Wikipedia)