Challenges of conducting a trial of uric-acid-lowering therapy in CKD.

Observational studies have shown that asymptomatic hyperuricemia is associated with increased risks of hypertension, chronic kidney disease (CKD), end-stage renal disease, cardiovascular events, and mortality. Whether these factors represent cause, consequence or incidental associations, however, remains uncertain. Hyperuricemia could be a consequence of impaired kidney function, diuretic therapy or oxidative stress, such that elevated serum urate level represents a marker, rather than a cause, of CKD. On the other hand, small, short-term, single-center studies have shown improvements in blood-pressure control and slowing of CKD progression following serum urate lowering with allopurinol. An adequately powered randomized controlled trial is required to determine whether uric-acid-lowering therapy slows the progression of CKD. This article discusses the rationale for and the feasibility of such a trial. International collaboration is required to plan and conduct a large-scale multicenter trial in order to better inform clinical practice and public health policy about the optimal management of asymptomatic hyperuricemia in patients with CKD.