Fibroblast growth factor-19: development, analytical characterization and clinical evaluation of a new ELISA test.

Objective: Since fibroblast growth factor 19 (FGF-19) is a potent metabolic regulator that influences glucose and lipid homeostasis, our aim was to develop an ELISA assay for measuring FGF-19 in human serum and to investigate its concentrations in healthy volunteers and patients suffering from metabolic syndrome.

Material And Methods: A sandwich ELISA method was developed for quantitative determination of human FGF-19 in serum samples. Blood pressure, waist circumference, FGF-21 serum levels, serum cholesterol, triacylglycerols, HDL-cholesterol, LDL-cholesterol, insulin, glucose, adiponectin, uric acid, creatinine, hs-CRP and calculated BMI and Quicki insulin sensitivity index were measured in 153 healthy volunteers and 66 persons with metabolic syndrome.

Results: Neither sex nor age influenced FGF-19 serum concentration in the healthy volunteers. Probands with metabolic syndrome had 65 % lower FGF-19 serum values than the healthy ones (medians 158.6 versus 242.4 ng/L; p<0.01). FGF-19 correlated with glucose (r = -0.35, p<0.01), HDL (r = 0.24, p = 0.045), triacylglycerols (r = -0.19, p = 0.05) and with a number of other risk factors for metabolic syndrome (r = -0.28, p = 0.01). When adjusted to the concentrations of triacylglycerols, BMI and glucose, and finally to all data pertinent to FGF-19 (according to correlation analysis), our data indicate that FGF-19 is an independent marker of metabolic syndrome.

Conclusions: The present study demonstrates the analytical properties of the ELISA FGF-19 assay and its usefulness when studying the metabolic syndrome. Serum concentrations of FGF-19 could be new key predictors of metabolic syndrome and thereby even a new negative risk factor of atherosclerosis.