Increased levels of fibroblast growth factor 23 (FGF-23) are commonly found in hemodialysis (HD) patients, a new study confirms. Whether FGF-23, a hormone involved in phosphate regulation and vitamin D metabolism, plays a role in vascular calcification is still unclear.
Cardiovascular calcification has been linked with an increased risk of death in HD patients. Since previous research on FGF-23 and calcification yielded mixed results, Tarek Zakaria El Baz, MD, of Al Azhar University in Cairo, and colleagues investigated the relationship between plasma intact FGF-23 and calcification in the coronary arteries and abdominal aorta. Among 60 maintenance HD patients free of diabetes, all had elevated FGF-23 (280.7 pg/mL). Half also showed abdominal aortic calcification on basal abdominal X-ray. Multislice computerized tomography scan performed on these patients provided their coronary artery calcification score.
Increased FGF-23 correlated with aortic and coronary calcifications. FGF-23 also showed associations with cardiovascular risk factors, including lipid profile, left ventricular mass index (LVMI), inflammatory markers, and age. Older age, in turn, was associated with higher body mass index, longer HD vintage, and higher abdominal aortic calcification score.
Despite these associations, the investigators found no direct evidence that FGF-23 predicts vascular calcification. “Possibly through its disturbing effects on minerals and parathyroid hormone, FGF-23 might indirectly affect vascular calcification,” Dr El Baz and colleagues wrote in the Saudi Journal of Kidney Diseases and Transplantation. “LVMI was higher in patients with vascular calcification and correlated positively with it.” Greater LVMI was associated with both aortic and coronary calcifications.
1. El Baz TZ, Khamis OA, Gheith OAA, Abd Ellateif SS, Abdallah AM, Abd El Aal HC. Relation of Fibroblast Growth Factor-23 and Cardiovascular Calcification in End-stage Kidney Disease Patients on Regular Hemodialysis. Saudi J Kidney Dis Transpl 2017;28(1):51-60.