Renoprotective effects of genetically proxied fibroblast growth factor 21: Mendelian randomization, proteome-wide and metabolome-wide association study

•We identify a clinically validated genetic instrument to study the effect of FGF21.•Instrumented FGF21 has pleiotropic effects extending beyond the liver.•FGF21 is likely to be efficacious for preventing and treating kidney disease.•Instrumented FGF21 is associated with a favorable metabolic profile.•Instrumented FGF21 affects levels of numerous plasma proteins and metabolites.