To investigate the potential mediator of the liver-heart axis, we measured serum FSTL3 of 323 T2DM and co-existent NAFLD patients (132 had AMI, and another 191 without AMI served as controls) who had serum samples in 995 T2DM co-existent NAFLD patients. This evidence concerns the gene FSTL3 and metabolic dysfunction-associated steatotic liver disease.