The relationship between carotid intima media thickness and left ventricular mass index with the level of serum FGF23 in chronic renal failure patients

Introduction and Objective: FGF23 is, a new hormone that plays a role in regulation of phosphate and vitamin D metabolism, which is mainly synthesized by osteocytes and also progressively increases to compensate for persistent phosphate retention in chronic renal failure. Cardiovascular diseases are the major cause of death in patients with end-stage renal failure. The contribution of high FGF 23 levels to cardiac disorders and atherosclerosis in chronic renal failure patients are uncertain. In this study, we analyzed the relationship between carotid intima media thickness and left ventricular mass index with the level of serum FGF23 in chronic renal failure patients. Materials and Methods: In this study, 162 patients in stage 2-5 chronic renal failure admitted to Cukurova University Nephrology Department in 2011-2013, were included. The age, height, weight, body mass index, body surface area measurements, the cause and duration of renal failure, drugs, smoking, alcohol habits and physical examination findings of the patients were recorded. Serum FGF23, glucose, BUN, creatinine, albumin, calcium, phosphorus, PTH, 25 (OH) vitamin D were studied. Also 24-hour urine protein and phosphorus were studied. USCN Life Science Inc. Wuhan, China ELISA kit was used for serum FGF-23 measurements. Vertebral carotid doppler ultrasonography and echocardiography imaging modalities were performed. Patients were classified according to stages thereafter evaulated the association between serum FGF23 levels and carotid intima-media thickness and left ventricular mass index. Results: In advanced stages of chronic kidney disease (stage 4-5) serum FGF23 levels (p=0.046), and carotid intima-media thickness (p=0.001) were higher when compared to the early stages of disease (stage 2-3). Left ventricular mass index was found increased with the progression of chronic renal failure (p = 0.015). Serum FGF23 levels and left ventricular mass index (p=0.004) and left ventricular concentric hypertrophy (p=0.017) were positively correlated. There wasn?t a significant relationship between Serum FGF23 levels and carotid intima-media thickness and carotid calcification. Serum creatinine (p=0.007), CRP (p=0.051), ferritin (p=0.007) and PTH (P=0.004) levels were positively correlated with serum FGF23 but there was no correlation between serum 25 (OH) vitamin D, calcium, and phosphorus. Left ventricular mass index was positively corelated left common carotid intima-media thickness (p<0.001), proteinuria (p<0.001), serum creatinine (p=0.031). Left ventricular mass index was negatively corelated albumin (p<0.001), serum 25 (OH) vitamin D (p:0.049). Carotid intima-media thickness was positively corelated left ventricular mass (p<0.001), left ventricular mass index (p=0.005), interventricular septum thickness (p=0.0011), left atrial diameter (p=0.023) heart posterior wall diameter (p=0.002), age (p<0,001) and HbA1c (p=0.023). Carotid intima-media thickness was negatively corelated cardiac ejection fraction (p=0.003). Carotid artery calcification was positively corelated serum phosphorus (p=0.01), CaxP (p=0.01), age (p=0.002), systolic BP (p=0.027), CRP (p=0.008), ferritin (p=0.027) values Conclusion: We found that there was a positively corelation serum FGF23 levels between left ventriculer mass index and concentric left ventricular hypertrophy. The results has been suggested that FGF23 is contributing to the risk of cardiovascular disease in patients with chronic renal failure. Serum FGF23 levels were not associated with carotid intima-media thickness. Carotid intima-media thickness may use as cheap, convenient, non-invasive measurement for cardiac functions. In conclusion our study revealed higher levels of FGF23 are more valuable indicator in evaluation of especially left ventricular mass index. Key Words: Carotid intima-media thickness, FGF23, left ventricular mass index, chronic renal failure.