Association of serum fibroblast growth factor 21 levels with skeletal muscle mass and mortality in chronic hemodialysis patients

Background/purpose: Fibroblast growth factor 21 (FGF21) is a hormone that modulates metabolic pathways, which acts as a myokine under metabolic stress. We aimed to explore the association of serum FGF21 levels with skeletal muscle mass and mortality in patients on hemodialysis (HD). Methods: Baseline serum FGF21 levels were measured, and a portable whole-body bioelectrical impedance device was used to assess skeletal muscle mass. One hundred twenty-four patients undergoing chronic HD were categorized into high-and low-FGF21 groups according to the median FGF21 value. Results: Patients with low FGF21 values had lower body weight, body mass index, skeletal muscle mass index (SMI Z skeletal muscle mass/height2), and serum triglyceride levels. Log serum FGF21 levels revealed a modest but positive correlation with SMI (r Z 0.30, p Z 0.001) and independently predicted SMI after multiple adjustment (b Z 1.59, p Z 0.027). During a median follow-up period of 66 months, all-cause mortality and cardiovascular death rates did not differ significantly between the high- and low-FGF21 groups. We also failed to demonstrate FGF21 as an independent predictor of all-cause mortality. Conclusion: Serum FGF21 levels exhibited a positive association with skeletal muscle mass but were not predictive of mortality in patients undergoing chronic HD. Copyright (c) 2022, Formosan Medical Association. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/bync-nd/4.0/).