From the Guidelines
Uric acid levels should not be used as the sole diagnostic criterion for acute gout, as approximately 30% of patients may have normal levels during an acute attack. According to the American College of Physicians guideline on management of acute and recurrent gout 1, the target thresholds for serum urate levels rely on the chemistry of urate, which is soluble up to a concentration of about 404 µmol/L (6.8 mg/dL), above which precipitation may occur. However, this threshold is not absolute because patients with higher serum urate levels may still be asymptomatic, and some may have acute flares below this threshold. Some key points to consider when evaluating uric acid levels in acute gout include:
- Normal uric acid levels range from 3.5-7.2 mg/dL in men and 2.6-6.0 mg/dL in women
- Patients experiencing acute gout often have levels exceeding 6.8 mg/dL, but approximately 30% of patients may have normal uric acid levels during an acute attack
- Joint fluid analysis showing monosodium urate crystals is more reliable than serum uric acid levels for diagnosis
- Treatment focuses on anti-inflammatory medications like colchicine, NSAIDs, or corticosteroids rather than immediately starting urate-lowering therapy
- Urate-lowering medications like allopurinol should typically be initiated after the acute attack resolves, usually waiting 1-2 weeks, to avoid worsening or prolonging the attack, as supported by the American College of Physicians guideline 1. The goal of long-term therapy is to maintain uric acid levels below 6.0 mg/dL to prevent future attacks and crystal deposition, as achieving lower urate levels after 1 year of urate-lowering therapy has been shown to result in fewer gout flares 1.
From the Research
Uric Acid Levels in Acute Gout
- Uric acid levels play a crucial role in the management of gout, as the disease is caused by the deposition of monosodium urate crystals in joints and tissues 2
- During an acute gouty attack, the focus is on reducing acute inflammation, rather than immediately lowering uric acid levels 3
- The treatment of acute gout typically involves non-pharmacological measures such as rest and ice, as well as pharmacological treatments like NSAIDs, colchicine, and corticosteroids 3, 4, 5, 2, 6
- Urate-lowering therapy is usually initiated after the acute attack has resolved, with the goal of preventing future flares and reducing serum uric acid levels to a target value of <6 mg/dL 4, 5, 2, 6
Management of Uric Acid Levels
- The management of uric acid levels in gout involves a treat-to-target strategy, with the goal of reducing serum uric acid levels to a target value 5
- Urate-lowering therapies, such as allopurinol and febuxostat, are used to prevent gout flares and reduce serum uric acid levels 4, 5, 2, 6
- Uricosuric agents, such as probenecid and benzbromarone, can also be used to lower uric acid levels, particularly in patients who are allergic to allopurinol or have renal insufficiency 3, 5, 6
- Emerging therapies, such as novel uricosurics and IL-1β antagonists, are being developed to improve the management of gout and uric acid levels 5, 6