Lower circulating irisin levels in type 2 diabetes mellitus patients with chronic complications: A meta-analysis

Purpose: The aim of this study was to provide evidence of the differences in circulating irisin levels between type 2 diabetes mellitus (T2DM) patients with and without chronic complications.Methods: We performed a meta-analysis to compare circulating irisin levels between different groups. Literature search was conducted in PubMed, Cochrane Library, Embase, WanFang, and China National Knowledge Infrastructure databases from inception through December 2022. Random effects model and standard mean difference (SMD) was used to calculate the pooled outcomes with 95 % confidence intervals (CIs).Results: Forty-two studies that matched the inclusion criteria were analyzed. Circulating irisin levels were significantly lower in T2DM patients with chronic complications than those in T2DM patients without chronic complications (SMD: -1.43; 95 % CI: -1.76 to -1.09; p < 0.00001) and healthy control group (SMD: -2.40; 95 % CI: -3.02 to -1.77; p < 0.00001). Moreover, irisin levels further decrease with the aggravation of complications in T2DM patients with diabetic nephropathy or diabetic retinopathy.Conclusion: Compared with T2DM patients without chronic complications, T2DM patients with chronic complications had lower circulating irisin levels. In addition, irisin levels were negatively correlated with the severity of chronic complications.