Critical appraisal of serum urate targets in the management of gout

Abstract

Gout management involves two broad aspects: treatment of gout flares to provide rapid symptomatic relief and long-term urate-lowering therapy to lower serum urate sufficiently to prevent gout flares from occurring. All of the major rheumatology societies recommend a target serum urate of <5 mg/dl (<0.30 mmol/l) or <6 mg/dl (<0.36 mmol/l), both of which are below the point of saturation for urate and therefore lead to monosodium urate crystal dissolution. In this Review, we describe the rationale for treat-to-target urate approach in the long-term management of gout and the current evidence and controversy around the appropriate serum urate targets.

Key points

• The major rheumatology societies all recommend a treat-to target serum urate approach with the targets being <5 mg/dl (0.30 mmol/l) or <6 mg/dl (<0.36 mmol/l).

• The treat-to target serum urate strategy for the management of gout has been questioned with the American College of Physicians, which states that insufficient evidence exists for such an approach.

• Sustained reduction in serum urate to levels <6 mg/dl (<0.36 mmol/l) is associated with a reduction in the dissolution of gout flares and tophi but these clinical benefits take time to occur.

• More than one target might be appropriate during gout management, with a lower target (<5 mg/dl (0.30 mmol/l)) in the initial phase of urate-lowering treatment and a higher target (<6 mg/dl (< 0.36 mmol/l)) once the flares and tophi have resolved.

• Which serum urate target results in the best clinical outcomes for people with gout remains to be determined.