RBP4 and liver disorder: OR, odds ratio; CI, confidence interval; NAFLD, non‐alcoholic fatty liver disease; MASLD, metabolic dysfunction‐associated steatotic liver disease; T2DM, type 2 diabetes mellitus; NASH, non‐alcoholic steatohepatitis; FGF21, fibroblast growth factor 21; RBP4, retinol‐binding protein 4; LECT2, leukocyte cell‐derived chemotaxin 2