Taking 81 mg of aspirin daily for two weeks before sleep loss does not change baseline immune cell counts in healthy adults, and any immune changes from aspirin only happen during sleep deprivation.
Mechanism
Synthesis from 1 study
Aspirin only affects immune cells when sleep is poor because that’s when the body starts producing signals that pull immune cells into the blood. Aspirin blocks those signals, so the cells don’t increase. When sleep is normal, those signals aren’t active, so aspirin does nothing.
Most probable mechanism
When a person doesn't get enough sleep, their body releases chemicals that tell certain immune cells to move into the bloodstream. A low dose of aspirin blocks the production of these chemicals, so the immune cells don't increase during poor sleep. But when sleep is normal, these chemicals aren't being made in large amounts, so aspirin has nothing to block and doesn't change anything.
Sleep restriction increases production of pro-inflammatory cytokines and lipid mediators that stimulate bone marrow to release eosinophils, basophils, and monocytes into circulation
Low-dose acetylsalicylic acid irreversibly inhibits cyclooxygenase enzymes, preventing synthesis of prostaglandins including PGE2
Reduced prostaglandin signaling diminishes chemotactic signals that recruit eosinophils and basophils from bone marrow and tissues into peripheral blood
Suppressed prostaglandin activity normalizes CD4/CD8 T-cell ratio by reducing preferential activation and proliferation of CD4+ T cells over CD8+ T cells
Inhibition of prostaglandin synthesis interferes with resolution pathways that clear monocytes after sleep loss, resulting in prolonged peripheral elevation despite recovery sleep
Evidence from Studies
Supporting (1)
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The Effect of Low-Dose Acetylsalicylic Acid on Cellular Immune Responses to Experimental Sleep Restriction in Healthy Humans
Contradicting (0)
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