Editing Sleep debt (section)

==Evaluation==

Sleep debt has been tested in a number of studies through the use of a [[sleep onset latency]] test.<ref>{{cite journal | vauthors = Klerman EB, Dijk DJ | title = Interindividual variation in sleep duration and its association with sleep debt in young adults | journal = Sleep | volume = 28 | issue = 10 | pages = 1253–9 | date = October 2005 | pmid = 16295210 | pmc = 1351048 | doi = 10.1093/sleep/28.10.1253 }}</ref> This test attempts to measure how easily a person can fall asleep. When this test is done several times during the day, it is called a [[multiple sleep latency test]] (MSLT). The subject is told to go to sleep and is awakened after determining the amount of time it took to fall asleep. The [[Epworth Sleepiness Scale]] (ESS), an eight-item questionnaire with scores ranging from 0 to 24, is another tool used to screen for potential sleep debt.

A January 2007 study from [[Washington University in St. Louis]] suggests that saliva tests of the enzyme [[amylase]] could be used to indicate sleep debt, as the enzyme increases its activity in correlation with the length of time a subject has been deprived of sleep.<ref>{{cite web |date=January 25, 2007 |title=First Biomarker for Human Sleepiness Identified |url=https://record.wustl.edu/news/page/normal/8539.html |publisher=[[Washington University in St. Louis]]}}</ref>

The control of wakefulness has been found to be strongly influenced by the protein [[orexin]]. A 2009 study from Washington University in St. Louis has illuminated important connections between sleep debt, orexin, and [[amyloid beta]], with the suggestion that the development of [[Alzheimer's disease]] could hypothetically be a result of chronic sleep debt or excessive periods of wakefulness.<ref name="kang">{{cite journal | vauthors = Kang JE, Lim MM, Bateman RJ, Lee JJ, Smyth LP, Cirrito JR, Fujiki N, Nishino S, Holtzman DM | title = Amyloid-beta dynamics are regulated by orexin and the sleep-wake cycle | journal = Science | volume = 326 | issue = 5955 | pages = 1005–7 | date = November 2009 | pmid = 19779148 | pmc = 2789838 | doi = 10.1126/science.1180962 | bibcode = 2009Sci...326.1005K }}</ref>