OBJECTIVE: During the aging process, a decrease in irisin levels is associated with numerous bone and muscle diseases. This study aims to provide evidence of circulating irisin levels in patients with sarcopenia. METHODS: This systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standard and the recommendations of the Cochrane Collaboration. A comprehensive search was conducted in PubMed, Embase, Web of Science databases, and other sources from their establishment until August 2023. The Review Manager software version 5.4 was used to calculate the standard mean difference (SMD). I RESULTS: 12 studies involving 2133 participants who met the inclusion criteria were analyzed. We found that irisin levels were significantly lower in patients with sarcopenia (SMD: - 1.28
95% CI - 1.65, - 0.90
I CONCLUSION: No matter the study area, study design, blood samples, or diagnostic criteria, the concentration of circulating irisin in patients with sarcopenia was lower than that in the control group.