Partial sleep deprivation reduces natural killer cell activity in humans.
Level 3 - non-randomized controlled study
Single-arm prospective before-after experimental study in healthy human volunteers serving as their own baseline controls
PubMed 7871104 · doi:10.1097/00006842-199411000-00004
What was done
Natural killer (NK) cell activity was assessed in 23 medically and psychiatrically healthy male volunteers across three baseline measurements, after one night of late-night partial sleep deprivation (awake between 3:00 AM and 7:00 AM), and after one night of resumed nocturnal sleep.
What was found
After partial sleep deprivation, NK cell activity fell in 18 of the 23 subjects, with average lytic activity significantly reduced (p < .01) to 72% of the baseline mean. Following one night of recovery sleep, NK cell activity returned to baseline levels.
Why it matters
The study indicates that modest, acute sleep loss directly and reversibly reduces innate cellular immune function in humans, independent of mood disturbance.
Limits
The trial had a small sample size of 23 participants, included only healthy men, and lacked a parallel non-deprived control group. Clinical infection endpoints were not evaluated.
Cited by
- contradicts Restricting healthy individuals to four hours of sleep for a single night leads to a 70% reduction in natural killer cell activity.