Immune response
The impact of too little sleep on the immune system has not received very much attention even though sleep deprivation has been shown to activate defense mechanisms and to elevate certain inflammatory cytokines or cell "messengers" (IL-6, TNF) in young adults. In an experiment, healthy participants had their sleep restricted to six hours per night; results found the 24-hour secretory profile of IL-6 was increased in both sexes and TNF-alpha was increased in men. Both IL-6 and TNF-alpha are markers of systemic inflammation, which causes pain and soreness and may lead to osteoporosis or autoimmune diseases.
In another study, researchers reported sleep restriction decreased antibody production to vaccination. In participants vaccinated for influenza immediately following a six night run of short sleep (four hours per night), the level of antibodies decreased by more than 50 percent 10 days following the vaccination compared to those vaccinated after a six night run of regular sleep.