The association between retinol-binding protein 4 and risk of type 2 diabetes: A systematic review and meta-analysis.

Retinol-binding protein 4 (RBP4) was controversially associated with type 2 diabetes mellitus (T2DM). This meta-analysis aimed at evaluating the association between RBP4 level and T2DM risk. MEDLINE and EMBASE were searched to identify relevant studies up to 3 December 2022. Random effects model was used to pool multivariate-adjusted odds ratios () and 95% confidence intervals (). Publication bias was estimated by Funnel plot and Egger's test, it was considered to be significant when  < 0.05. Eight studies including 8087 participants were finally included. Compared to those with the lowest level, subjects with the highest level of RBP4 have a higher risk of T2DM ( = 1.47, 95% : 1.16-1.78,  < 0.001,  = 86.9%). No publication bias among the included studies was found ( = 0.94,  = 0.377). This meta-analysis indicated that high RBP4 level was associated with increasing risk of T2DM.