Fibroblast growth factor 21 as marker of low protein intake in patients with disease-related malnutrition

Introduction: FGF21 has potential functions as a key regulator in coordinating the metabolic response to protein deficiency. Objective: the aim of our design is to explore the role of circulating FGF21 in patients with disease-related-malnutrition (DRM) and its relationship with protein dietary intake. Material and methods: 108 DRM patients were included. Bioelectrical impedance analysis was conducted to assess skeletal muscle mass (SMM), appendicular skeletal muscle mass (aSMM), and the appendicular skeletal muscle mass index (aSMMI). Muscle mass was evaluated using ultrasound at the rectus femoris quadriceps (RFQ) level, too. Handgrip strength, biochemical parameters, dietary intake, and circulating FGF21 levels were also measured. Results: mean age was 61.3 ± 1.1 years. A negative correlation between FGF21 levels and some parameters of rectus femoris quality (RFQ) such as dominant muscle area, reactance, SMM, aSMM and albumin levels were reported. Protein intake was negatively correlated (r = -0.55; p = 0.02), too. Patients with higher protein intake (median intake 53.7 g/day) had higher dominant muscle area RQF (0.6 ± 0.2 cm2; p = 0.03), reactance (7.5 ± 0.3; p = 0.03), SMM (2.6 ± 0.3 kg; p = 0.03), aSMM (2.3 ± 0.8 kg; p = 0.03), albumin (0.7 ± 0.2 mg/dL; p = 0.04), prealbumin (10.1 ± 0.8 mg/dL; p = 0.02) and lower levels of FGF21 (86.5 ± 9.8 ng/dL; p = 0.01). Patients with FGF21 levels above the median cut-off point (61.3 ng/mL) had a significantly higher risk of low protein intake (OR = 2.47, 95 % CI = 1.14-5.35; p = 0.02). Conclusion: a significant association between increased serum FGF21 levels and low protein dietary intake is reported in patients with DRM.