One night of sleep loss has a tissue-specific impact on the regulation of gene expression and metabolism in humans. This may explain how shift work and chronic sleep loss impairs our metabolism and adversely affects our body composition.
In a new study, researchers at Uppsala University studied 15 healthy normal-weight individuals who participated in two in-lab sessions in which activity and meal patterns were highly standardised. In randomised order, the participants slept a normal night of sleep (over eight hours) during one session, and were instead kept awake the entire night during the other session. The morning after each night-time intervention, small tissue samples (biopsies) were taken from the participants' subcutaneous fat and skeletal muscle. These two tissues often exhibit disrupted metabolism in conditions such as obesity and diabetes. At the same time in the morning, blood samples were also taken to enable a comparison across tissue compartments of a number of metabolites. These metabolites comprise sugar molecules, as well as different fatty and amino acids.
These observations may provide at least partial mechanistic insight as to why chronic sleep loss and shift work can increase the risk of adverse weight gain as well as the risk of type 2 diabetes