White Paper: How Much Sleep Do Adults Need?
the development of diabetes-(16), and increased hunger/appetite (which could promote obesity -(17) In addition, information obtained from questionnaires in large sample groups has also shown statistical associations between chronically reduced sleep duration and increased risk of hypertension (particularly in women) (18), (19); diabetes(20); and weight gain(21), (22), (23). These results are particularly meaningful because they agree with the results of studies that examined these issues by experimentally reducing the participants' time in bed. There is also a suggestion that sleep restriction may adversely affect immune function. In one study, young adults who had been given a flu shot after four nights of reduced sleep had less than half of the antibody response 10 days later compared with individuals having normal sleep at the time of vaccination (24). Changes in these clinical markers after only a few nights of partial sleep loss typically reverse when normal sleep is allowed. However, it is important to recognize that many of the above studies examined the effects of relatively short-term alteration in sleep duration but many individuals in the community may have chronic partial sleep deprivation. The consequences and reversibility of any consequences in this regard are not known.
The results of studies done to date imply that numerous health consequences could be associated with sleep restriction. In contrast, increased sleep duration has not been associated with immediate negative health consequences. However, controlled long-term studies remain to be done.