The effect of disrupted sleep on macrophage polarization: a systematic review and meta-analysis of animal studies

Based on the bidirectional relationship between sleep and macrophages in healthy and diseased states, this systematic review and meta-analysis investigated the effect of disrupted sleep on macrophage polarization.

A literature search was conducted in PubMed, Scopus, and Web of Science (WoS) databases up to October 2023, identifying English-language studies on disrupted sleep's effects on macrophage polarization. After screening and data extraction, the standardized mean difference (SMD) with a 95% Confidence Interval (CI) was calculated for M1 pro-inflammatory and M2 anti-inflammatory markers. Heterogeneity was assessed using Cochran's Q test and the I-square (I²) statistic, and subgroup analyses were performed. The methodological quality was assessed using SYRCLE's RoB tool. Publication bias was examined through Egger's test and the trim-and-fill method, and a sensitivity analysis was also conducted. The meta-analysis was performed using STATA version 14.2 software.

Thirteen studies were included. Results indicated that disrupted sleep significantly increased CD11c levels [SMD: 2.450, 95% CI: 1.517 to 3.383, I² = 11.7%], and decreased CD206 levels [SMD: -2.616, 95% CI: -4.911 to -0.321, I² = 83.3%]. The association between disrupted sleep and M1/M2 was uncertain, with sex identified as a potential source of heterogeneity. No publication bias or sensitivity was detected, which strengthens the reliability and robustness of the findings.

Disrupted sleep significantly influenced macrophage polarization towards a CD11c⁺ M1 inflammatory phenotype. Given the heterogeneity and limited number of studies, these findings should be interpreted as exploratory. Further research on the underlying mechanisms, particularly concerning biological sex, to better understand sleep's impact on immune function and treatment strategies for inflammatory conditions.