Serum Endocrine Fibroblast Growth Factors as Potential Biomarkers for Chronic Kidney Disease and Various Metabolic Dysfunctions in Aged Patients

Objective To prolong the health expectancy, it is important to prevent age-related diseases, such as osteoporosis and cerebrovascular disease, which are major causes of a bedridden state. Early predictable biomarkers for these diseases are urgently required in the clinical setting. Three members of the fibroblast growth factor (FGF) family - FGF19, FGF21, and FGF23 - are designated as endocrine FGFs and play crucial roles in various metabolic processes. We tried to clarify the clinical utility of endocrine FGFs as biomarkers for age-related diseases in elderly patients. Methods We examined the serum endocrine FGF levels and analyzed their association with various clinical parameters in 73 outpatients >60 years old as a single-center cross-sectional study. Results In a multivariable linear regression analysis, FGF19 was associated with ALT, a history of cardiovascular disease, and medication with active vitamin D3. FGF21 was associated with the estimated glomerular filtration rate (eGFR), triglyceride level, and hypertension. FGF23 was associated with the eGFR and the serum levels of 1,25-dihydroxy vitamin D3 and TRACP5b. In addition, a receiver operating characteristics analysis revealed that the measurement of FGF21 and FGF23 was useful for detecting chronic kidney disease (CKD) and its complications, including cardiovascular disease and metabolic bone disorder. Conclusion The measurement of FGF21 and FGF23 may be useful for evaluating CKD and its complications. Using serum endocrine FGFs as biomarkers for age-related conditions may help prevent elderly patients from entering a bedridden state.