Effects of Experimental Sleep Deprivation on Peripheral Inflammation: An Updated Meta-Analysis of Human Studies.

A precise understanding of the effects of experimental sleep deprivation on inflammation is necessary to refine theoretical perspectives on sleep-related immunopathological processes and implement robust empirical procedures. Here, we report an updated preferred reporting items for systematic reviews and meta-analysis systematic review and meta-analysis testing the effects of experimental total and partial sleep deprivation on circulating inflammatory markers in healthy adult individuals. PubMed, Scopus, PsycINFO, and CINAHL were searched up to March 2025. Data were analysed using the DerSimonian and Laird random effects approach. Of the 2264 articles retrieved, we included 35 studies reporting on 887 participants. Compared to normal sleep, multiple nights of experimental partial sleep deprivation (sleep duration reduced to ~4.30 h for 3+ nights) were associated with a significant increase of interleukin-6 [IL-6, k = 5, d = 0.42, [95% CI = 0.11 to 0.73], p < 0.01] and C-reactive protein [CRP, k = 5, d = 0.76, [95% CI = 0.09 to 1.43], p = 0.03] in blood. A single night of total or partial sleep deprivation was not associated with changes in inflammation. Results suggest that the upregulation of inflammatory proteins in blood may only manifest following persistent periods of partial sleep deprivation. Further research will be needed to determine whether sleep recovery strategies (e.g., naps, sleep extension) may restore immune homeostasis. We suggest that experimental partial sleep deprivation for at least 3 nights may elicit peripheral IL-6 and CRP and could therefore serve as a valid procedure to study sleep-related immunopathological processes.