Context: Fibroblast growth factor-21 (FGF21) is an important metabolic regulator suggested to improve glucose metabolism and prevent dyslipidemia. An FGF21-resistant state that increases circulating FGF21 has been reported in obese patients. Although regular exercise prevents metabolic disease, the relationship of the fitness level to serum FGF21 level and body fat distribution in humans remains poorly understood.
Objective: The objective of the study was to determine the relationship among the serum FGF21 concentration, cardiorespiratory fitness (CRF) level, and visceral fat area (VFA).
Design: Serum FGF21 was measured by an ELISA in 166 middle-aged and elderly Japanese men (aged 30-79 y) and 25 untrained and 21 endurance-trained young men (aged 19-29y). CRF was assessed by measuring the peak oxygen uptake (VO2peak) and VFA by magnetic resonance imaging.
Results: In the middle-aged and elderly subjects, the serum FGF21 level correlated with the VO2peak (r = -0.355, P <.001) and VFA (r= 0.487, P <.001). Stepwise multiple regression analysis showed VFA to be most strongly associated with the serum FGF21 level (β =.360, P <.001), and VO2peak was also an independent predictor of the serum FGF21 level (β = -.174, P =.019). Furthermore, the proportion of subjects with an FGF21 level below the limit of detection was significantly higher among the endurance-trained than among the untrained young men (71.4% vs24.0%, P=.001), and the VO2peak and VFA were independently associated with an undetectable FGF21 level (P <.05).
Conclusions: CRF and VFA are key determinants of the circulating FGF21 concentration.
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Clinical Biochemistry
- Biochemistry, medical