Similar to what reported in healthy subjects, DM2 patients were characterized by a positive correlation between plasma irisin levels and the arms and legs fat measured by DEXA, while in DM1 patients, no correlation could be detected with the total body and regional fat mass as well as with visceral adiposity parameters, such as waist circumference, liver steatosis, and epicardial fat thickness. Here, FNDC5 is linked to fatty liver disease.