Abstract

BACKGROUND:

Uric acid (UA) may play a pathogenetic role in hypertension and kidney disease. We explored the prevalence of hyperuricemia and the relationship of UA to graft function and hypertension in prevalent renal transplant recipients (RTR).

METHODS:

Baseline and follow-up data were collected on 90 RTR (mean age 51 yrs, 53% male, median transplant duration 7 years). Graft function was estimated using MDRD Study Equation 7.

RESULTS:

At baseline, 70% RTR had hyperuricemia (UA >7.0 mg/dl (0.42 mmol/L) in men and >6.0 mg/dl (0.36 mmol/L) in women) compared to 80% after 2.2 years (P=0.06). UA was not associated with blood pressure (BP) level but was higher in RTR with a history of hypertension compared to those without (8.6+/-1.8 vs. 7.3+/-2.2 mg/dl, [0.51+/-0.11 vs. 0.43+/-0.13 mmol/L], P=0.003) and in RTR on > or =3 antihypertensive medications compared to those taking less (9.1+/-1.6 vs. 7.6+/-1.8 mg/dL, [0.54+/-0.1 vs. 0.45+/-0.11 mmol/L], P<0.001). A history of hypertension was independently predictive of UA (beta 0.06, [95% CI 0.02 to 0.10], P=0.007) in addition to sex, cyclosporine dose, prednisolone dose, estimated glomerular filtration rate (eGFRMDRD) and beta-blocker therapy. UA was independently predictive of follow-up eGFRMDRD (beta -22.2 [95% CI -41.2 to -3.2], P=0.02) but did not predict change in eGFRMDRD over time. UA was independently associated with requirement for antihypertensive therapy (beta 0.34, [95% CI 1.05 to 1.90], P=0.02).

CONCLUSIONS:

Hyperuricemia is common in RTR and is associated with need for antihypertensive therapy and level of graft function.