Post-transplant Hyperuricemia as a Cardiovascular Risk Factor

Purpose. Uric acid is known to impair endothelial cell function and to stimulate the development of renal interstitial fibrosis. The aim of this study was to evaluate the association between first-year hyperuricemia with graft dysfunction and the development of cardiovascular risk disorders in renal transplant recipients. Methods. One hundred kidney transplant recipients (31 female, 45.9 +/- 9.6 post-transplantation months) with normal graft functions were enrolled. The clinical biochemical parameters in the first post-transplantation year were retrospectively recorded and searched for the predictive value in yearly determined graft function and association with cross-sectionally analyzed cardiovascular parameters, including body composition analyses, ambulatory blood pressure monitoring data, and pulse wave velocity. Hyperuricemia was defined as an uric acid level of >= 6.5 mg/dL that persisted for at least 2 consecutive tests. Results. One year after transplantation, 37% of subjects had hyperuricemia. According to cross-sectional data, sagittal abdominal diameter (P = .002) and hip circumferences (P = .013) were significantly higher in hyperuricemic patients than in normouricemic ones. Hyperuricemic patients had higher fat (P = .014) and muscle mass (P = .016) than normouremic patients. Hyperuricemic patients had significantly higher mean systolic BP (P = .044) than normouremic patients. Hyperuricemic patients had significantly higher pulse wave velocity levels (P = .0001) and left ventricular mass index (P = .044) than normouremic patients. The yearly decline in estimated glomerular filtration rate levels was significantly higher in hyperuricemic patients (P = .0001) than in normouricemic ones. Conclusion. Post-transplantation hyperuricemia is associated with hypertension, arterial stiffness, and dyslipidemia; it should be accepted not only as a marker for renal allograft dysfunction but also as a cardiovascular risk factor in renal transplant recipients.