Lack of sleep affects gene activity

One week of poor sleep can disrupt hundreds of genes linked to stress, immunity and inflammation, research here has shown. The discovery could explain why lack of sleep is so bad for the health. Sleep deficiency is associated with a host of conditions including obesity, heart disease and mental impairment. But scientists are still trying to understand the molecular mechanisms involved. For the new study, researchers examined gene activity in 26 sleep-deprived volunteers. They found that insufficient sleep had an impact on more than 700 genes. Some had their activity dampened, while others became extra-active. Those affected included genes associated with the circadian night and day "body clock" cycle, metabolism, and immune and stress responses. Poor sleep also altered chromatin - the DNA and protein "packaging" that plays an important role in gene regulation. The scientists, led by sleep expert Professor Derk-Jan Dijk, from the University of Surrey, outside London, wrote in the journal "Proceedings of the National Academy of Sciences", "Biological processes affected included chromatin modification, gene-expression (activity) regulation, macro-molecular metabolism, and inflammatory, immune and stress responses. "The identified biological processes may be involved with the negative effects of sleep loss on health, and highlight the inter-relatedness of sleep homeostasis (stability), circadian rhythmicity, and metabolism." Participants were exposed to a week of poor sleep during which they slept no more than six hours a night.