The effects of FGF23 and Klotho on vascular calcification in end stage renal disease patients;

Vascular calcification and arterial stiffness, precipitated by abnormal calcium
and phosphate metabolism in CKD, are related to the high cardiovascular
mortality in chronic kidney disease (CKD) patients1-3. High Fibroblast Growth
Factor (FGF)23 levels are associated with endothelial dysfunction, direct toxic
effects to the cardiac myocytes leading to left ventricular hypertrophy and
higher risk of cardiovascular events 4-7. The effects of elevated FGF23 levels
on vascular calcification remains controversial 8, 9.

The goal of this study is to evaluate if serum FGF23 levels are directly
related to cardiovascular calcification, measured as arterial stiffness with
pulse wave velocity. The primary objective is to evaluate if elevated serum
FGF23 and decreased klotho and vitamin D (25 (OH)D) concentrations are related
to increased arterial stiffness as measured by a carotid-femoral pulse wave
velocity meter in patients with chronic kidney disease.
As a secondary objective, the study assesses correspondence between pulse wave
velocity estimated from skin reflectivity (photoplethysmogram, PPG) and
acceleration data simultaneously acquired at wrist, ankle and torso and pulse
wave velocity obtained using a carotid-femoral pulse wave velocity meter.

Cross-sectional single center study.

Patients visit the out-patient clinic for routine check-up including their
regular blood sample drawn, which we will use to measure FGF23, klotho and
vitamin D concentrations. During this same appointment, patients undergo a
single lead ECG measurement , a carotid-femoral pulse wave velocity measurement
(cfPWV) and skin reflectivity (PPG) and acceleration measurements at wrist,
ankle and torso.