Fibroblast Growth Factor 21 (FGF21) is A Novel Sensitive Biomarker for the Diagnosis and Control of Hepatic Glycogenoses

Background: Fibroblast growth factor 21 (FGF21) is a growth factor with regulatory effects on glucose and lipid metabolism. Previous studies have shown that elevated serum FGF21 levels can serve as a diagnostic biomarker for various mitochondrial diseases. Recently, serum FGF21 was associated with long term complications in organic acidemias.

Objective: To study the utility of serum FGF21 levels as a biomarker in patients with confirmed diagnosis hepatic glycogenoses

Methods: FGF21 serum levels were assayed by ELISA kit in patients with various hepatic glycogen storage diseases (GSD). Three separate samples (random, fasting and postprandial) were obtained and compared with normal controls.

Results: The cohort included 11 patients with various hepatic GSDs as follows: two with GSD1a, one with GSD1b, four with GSD3, one with GSD6 and one with GSD9b. Serum FGF21 were significantly elevated at all three conditions compared to normal levels; random samples 564±720pg/ml (normal level 0-250pg/ml, p<0.001), fasting sample 1446±1755pg/ml (normal level 0-250pg/ml, p<0.001), post prandial samples 759±509pg/ml (normal level 0-250pg/ml, p<0.001). In the same individual serum FGF21 levels were significantly higher during fasting compared with postprandial condition (Z=-2.52, p<0.04)

Discussion: Our results suggest serum FGF21 can serve as a reliable biomarker for the diagnosis of hepatic GSD. We demonstrate that its levels are dependent on fasting/satiation. Future studies are needed to confirm its role in better metabolic control of GSD patients.