Role of uric acid in post-renal transplantation hypertension.

Uric acid (UA) is an emerging cardiovascular (CV) risk factor that is associated with hypertension and CV disease (CVD) in the general population, but whose role in renal transplant recipients (RTR) has not been defined. We performed a retrospective chart review of 589 stable RTR receiving ongoing posttransplant care at our hospital, identifying those with a minimum of 3 serum UA measurements obtained at least 2 months posttransplantation, 6 months graft survival, stable renal function, and no change in antihypertensive or immunosuppressive drugs over this time. Data were collected for the period November 2005 to July 2007. Relationships were assessed by Pearson's correlation coefficient, and correlates of UA including blood pressure (BP) were determined using multiple linear regression analysis. There were 464 RTR who met eligibility criteria for the study. Hyperuricemia was present in 196 patients (42%). By Pearson's correlation coefficient, UA was inversely correlated with estimated glomerular filtration rate (eGFR; R = -.39; P < .0001) and directly correlated with C-reactive protein (CRP; R = .10; P = .02). However, UA did not correlate with either age (R = .07; P = .08) or systolic BP (R = .05; P = .76). Upon multivariate linear regression, UA was inversely associated with eGFR (P < .0001) and directly associated with male gender (P < .0001), use of cyclosporine (CsA; P = .0002), increasing time posttransplantation (P = .007), and CRP (P = .01). In summary, hyperuricemia is common in RTR, but was not related to BP. Further studies are required to establish whether UA predicts CV risk in this population.

Pre-transplantation glucose testing for predicting new-onset diabetes mellitus after renal transplantation.

AIM: New-onset diabetes after renal transplantation (NODAT) adversely affects graft and patient survival. However, NODAT risk based on pre-transplant blood glucose (BG) levels has not been defined. Our goal was to identify the best pre-transplant testing method and cut-off values. MATERIALS AND METHODS: We performed a case-control analysis of non-diabetic recipients who received a live donor allograft with at least 6 months post-transplant survival. Pre-transplant glucose abnormalities were excluded through 75 g oral glucose tolerance testing (OGTT) and random BG (RBG) measurement. NODAT was defined based on 2003 Canadian Diabetes Association criteria. Multivariate logistic and Cox regression analysis was performed to determine independent predictor variables for NODAT. Receiver-operating-characteristic (ROC) curves were constructed to determine threshold BG values for diabetes risk. RESULTS: 151 recipients met initial entry criteria. 12 had pre-transplant impaired fasting glucose and/or impaired glucose tolerance, among who 7 (58%) developed NODAT. In the remaining 139, 24 (17%) developed NODAT. NODAT risk exceeded 25% for those with pre-transplant RBG > 6.0 mmol/l and 50% if > 7.2 mmol/l. Pre-transplant RBG provided the highest AUC (0.69, p = 0.002) by ROC analysis. Increasing age (p = 0.025), acute rejection (p = 0.011), and RBG > 6.0 mmol/l (p = 0.001) were independent predictors of NODAT. CONCLUSION: Pre-transplant glucose testing is a specific marker for NODAT. Patients can be counseled of their incremental risk even within the normal BG range if the OGTT is normal.