Fewer than 6 hours of sleep alters genes

As little as one week of inadequate sleep is enough to alter the activity of hundreds of genes, researchers in Britain say. Derk-Jan Dijk, director of the Sleep Research Center at the University of Surrey, said the researchers monitored the activity of all genes of the human genome and found that inadequate sleep -- less than 6 hours a night -- affects the activity of more than 700 genes, genes linked to controlling inflammation, immunity and the response to stress. The research showed inadequate sleep reduced the number of genes that normally peak and wane in expression throughout the 24-hour day from 1,855 to 1,481. The authors said the number of genes affected by sleep deprivation was seven times higher after a week of insufficient sleep. Sleep deficiency leads to a host of significant health conditions including obesity, heart disease and cognitive impairment but until now scientists were unclear how gene expression patterns were altered by insufficient sleep, the study said.