Background:​ With emerging basic research evidence suggesting that fibroblast growth factor (FGF) 21 is a catabolic molecule on muscle metabolism, we aimed to analyze the serum FGF21 level in relation to sarcopenia in older adults.

Methods:​ Blood samples were collected from 125 participants who underwent evaluation for muscle mass and function in an outpatient geriatric clinic of a teaching hospital. Sarcopenia and related components were determined using cutoff values for the Asian population. The serum FGF21 level was measured using enzyme linked immunosorbent assay.

Results:​ After controlling for age, sex, and body mass index (BMI), participants with sarcopenia, low muscle mass, and weak muscle strength had 2.3-, 2.0-, and 1.5-fold higher serum FGF21 levels than controls, respectively (p = .033 to <0.001). The serum FGF21 level was positively correlated with sarcopenia phenotype score and inversely correlated with skeletal muscle mass index and grip strength by both crude and multivariate analysis adjusting potential confounders (p = .017 to <0.001). Consistently, higher serum FGF21 level was significantly associated with increased odds for sarcopenia, low muscle mass, and low muscle strength after adjusting for age, sex, and BMI (odds ratio, 1.53–2.61;​ p = .048 to <0.001).

Conclusions:​ Higher circulating FGF21 was associated with the likelihood of sarcopenia, lower muscle mass, and worse grip strength in older adults, supporting a potential catabolic role of FGF21 on human muscle health.