New research has shown that sleep deprivation profoundly disrupts the normal rhythm of gene expression, findings with potential health significance
It is already known that both sleep deprivation and the disruption of normal sleep patterns (due to ongoing international air travel or night-time shift work) are linked with adverse health outcomes, notably obesity, type 2 diabetes, heart disease and cancer, but the underlying biological mechanisms remain poorly understood.
UK researchers used volunteers to undergo one week of progressive sleep deprivation (based on an artificial 28-hour day) to mimic the effect of severe jet lag or working a night shift. They also had one week of normal sleep. During each week, blood samples were taken for analysis of gene expression.
Analysis of the transcriptome (actively expressed regions of the genome) showed that sleep deprivation altered the activity of over 700 genes, including genes associated with circadian rhythms, control of sleep, oxidative stress and metabolism, with observable effects on the inflammatory, immune and stress responses.
The number of genes showing circadian expression profiles (ie. 24-hour rhythms of activity) fell significantly whilst the number of genes showing altered activity in response to subsequent sleep deprivation rose sharply.
The researchers conclude that insufficient sleep disrupts the normal circadian regulation of the human blood transcriptome and intensifies the effects of acute total sleep deprivation, suggesting that the observed impact of sleep deprivation on health may be mediated by these effects and that further investigation is appropriate.
Comment: This is an interesting example of potential gene-environment interactions that could well be involved in health outcomes, though as the study involved only a short-term study of 22 people its findings are not necessarily typical.
However, an improved understanding of the biological effects of sleep deprivation on circadian rhythms is likely to be important for population and individual health. In population health terms, it could reveal ways to predict and reduce the risks posed by unavoidable sleep deprivation, whilst for individuals it can affect not only their long-term health outcomes but potentially also have more immediate effects, for example on the efficacy of medicines.