Sort of related: has there been any evidence as to why sleep deprivation kills you? A friend and I were hypothesizing about it once, although neither of us are particularly knowledgeable about biology so it was a bunch of probably wild guesses.
Effect of sleep loss on C-reactive protein, an inflammatory marker of cardiovascular risk. (http://www.med.upenn.edu/uep/user_documents/dfd10.pdf)
Short Sleep Duration Is Associated with Reduced Leptin, Elevated Ghrelin, and Increased Body Mass Index. (http://med.stanford.edu/school/Psychiatry/narcolepsy/article...)
Neurocognitive Consequences of Sleep Deprivation. (http://www.med.upenn.edu/uep/user_documents/DurmerandDinges-...)
Insomnia with Objective Short Sleep Duration is Associated with Type 2 Diabetes. (http://care.diabetesjournals.org/content/early/2009/07/28/dc...)
"Complete and partial lack of sleep increased the blood concentrations of High sensitivity C-Reactive Protein (hs-cRP), the strongest predictor of heart attacks. Even after getting adequate sleep later, the levels stayed high!
Just one night of sleep loss increases very toxic substances in body such as Interleukin-6 (IL-6), Tumour Necrosis Factor-Alpha (TNF-alpha) and C-reactive protein (cRP). They increase risks of many medical conditions, including cancer, arthritis and heart disease. Paper published in 2004."