Elevated inflammatory markers in response to prolonged sleep restriction are associated with increased pain experience in healthy volunteers

Haack M, Sanchez E, Mullington JM · Sleep

IL-6 separated between conditions (p = 0.04, effect size 0.92): 1.88 to 3.04 pg/mL under restriction against 3.15 to 2.36 pg/mL in controls, neither arm's own change significant. Bodily-discomfort ratings, which pooled joint pain with headache, back and muscle pain, rose 5.6% against a 0.8% fall in controls (p = 0.05), and the IL-6 change correlated r = 0.67 (p = 0.003) with the pain change, holding after adjustment for fatigue. CRP (p = 0.11), soluble TNF receptor and urinary prostaglandins did not separate — experimental evidence that sleep loss amplifies pain alongside a rise in IL-6.

Population

18 healthy volunteers aged 21-40 (10 restricted, 8 control) in a 16-day inpatient laboratory study, the placebo arm of a larger endotoxin protocol

Intervention

12 nights of sleep restricted to 4 h/night

Comparator

8 h/night sleep

Limitations

Healthy volunteers, not joint-disease patients; n=18 split 10 and 8; short duration; pain measured by self-report as a composite; the between-condition IL-6 effect is partly a fall in the well-slept controls. NIH-funded; the senior author reports speaking and advisory work for Takeda, Sanofi-Aventis and Jazz.