Fibroblast Growth Factor-23 Levels Are Associated With Uric Acid But Not Carotid Intima Media Thickness in Renal Transplant Recipients

Introduction. Cardiovascular disease (CVD) is the leading cause of mortality in chronic kidney disease (CKD) patients. Fibroblast growth factor-23 (FGF-23) is associated with atherosclerosis and cardiovascular mortality in CKD patients and healthy subjects. However, data in renal transplant recipients (RTR) are scarce. We aimed to determine factors associated with FGF-23 and to explore its relationship to atherosclerosis. Methods. Forty-six patients and 44 controls were included. FGF-23 was measured from plasma. Carotid intima media thickness (CIMT) was evaluated ultrasonographically. Results. Patients had higher waist circumference (WC; 92.2 +/- 14.9 vs 85.3 +/- 11.0 cm; P < .05), glucose (99.8 +/- 17.2 vs 90.3 +/- 6.5 mg/dL; P < .01), creatinine (1.43 +/- 0.6 vs 0.86 +/- 0.1 mg/dL; P < .01), triglyceride (160.4 +/- 58.9 vs 135.6 +/- 59.8 mg/dL; P < .05), white blood cells (WBC; 7938.6 +/- 2105.2 vs 6715.7 +/- 1807.5 WBC/mm(3); P < .01), ferritin (217.0 +/- 255.8 vs 108.3 +/- 142.4 ng/mL; P < .05), uric acid (6.5 +/- 1.6 vs 4.7 +/- 1.3 mg/dL; P < .01), C-reactive protein (CRP; 8.2 +/- 18.2 vs 5.3 +/- 7.9 mg/L; P < .01), parathyroid hormone (PTH; 89.7 +/- 59.2 vs 44.1 +/- 16.7 pg/mL; P < .01), and alkaline phosphatase (ALP; 162.5 +/- 86.6 vs 74.2 +/- 21.9 U/L; P < .01). FGF-23 was higher in patients (11.7 +/- 7.2 vs 9.6 +/- 6.8 pg/mL; P < .05). CIMT was similar (0.58 +/- 0.09 vs 0.57 +/- 0.1 mm; P > .05). WC, creatinine, and uric acid were positively correlated with FGF-23, whereas albumin showed negative correlation. On multivariate analysis only creatinine and uric acid were determinants of FGF-23. Conclusion. FGF-23 levels are associated with uric acid in RTR. Larger studies are needed to confirm this finding.