A study in which serum irisin concentrations were assessed by the enzyme-linked immunosorbent assay in 102 Parkinson′s disease (PD) patients and 35 age- and sex-matched controls demonstrated that serum irisin was significantly associated with sarcopenia and carotid atherosclerosis in peritoneal dialysis patients [57]. Here, FNDC5 is linked to carotid atherosclerosis.