Elderly renal transplant recipients and renal dysfunction: a risk factor for hyperuricemia

Abstract

Objectives: To date, limited data are currently available on posttransplant hyperuricemia in elderly renal transplant patients.

Materials and methods: We conducted a retrospective study on 120 renal transplant patients aged ≥ 60 years old who received a kidney with at least a minimum time of 1 year after transplant between 2008 and 2011 in Iran. Hyperuricemia was defined if serum uric acid was ≥ 416.36 μmol/L in men (7.0 mg/dL), and ≥ 356.88 μmol/L in women (6 mg/dL) that persisted for at least 2 consecutive tests. Moderate-to-severe hyperuricemia also was defined as a serum uric acid of ≥ 475.84 μmol/L (8.0 mg/dL) in both sexes.

Results: The majority of cases were men (66%) and only 9% received their grafts from deceased donors. The rate of deceased kidney transplant was higher in normouricemic patients. The prevalence of late posttransplant hyperuricemia was 37.5% of patients (n=45). Moderate-to-severe hyperuricemia was seen in 21 patients (17.5%). Although hyperuricemia was commonly observed in women than in men (43% in women vs 32% in men; P = .02), the rate of moderate-to-severe hyperuricemia was similar among both sexes (4.5% vs 4.3%; P = .9). Hyperuricemia frequently occurred in patients receiving kidney from a female donor (50% vs 29%; P = .005). In univariate analysis, a significant correlation was seen between serum uric acid and serum creatinine (r=0.5, P = .000). On multivariate regression, high serum creatinine was only a risk factor for posttransplant hyperuricemia in elderly kidney transplants (P = .000).

Conclusions: Posttransplant hyperuricemia was a quite common among elderly aged kidney recipients. It was correlated with renal allograft impairment.