From the Guidelines
Serum uric acid levels above 6.8 mg/dL (404 µmol/L) require medical attention, as levels above this threshold may lead to precipitation of urate crystals and increase the risk of gout flares. According to the American College of Physicians guideline on management of acute and recurrent gout 1, 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). The European League Against Rheumatism (EULAR) also recommends maintaining serum uric acid (SUA) levels at <6 mg/dL (360 mmol/L) and <5 mg/dL (300 mmol/L) in those with severe gout 1.
Some key points to consider when evaluating serum uric acid levels include:
- The association between lower urate levels and fewer gout flares, although the extent to which use of urate-lowering therapy to achieve various targets can reduce gout flares is uncertain 1
- The importance of considering individual patient factors, such as symptoms, medical history, and lifestyle, when determining the need for medical attention 1
- The role of urate-lowering therapy, such as allopurinol or febuxostat, in managing gout and reducing serum uric acid levels 1
In terms of treatment, lifestyle modifications, such as maintaining a healthy weight, limiting alcohol, and reducing intake of purine-rich foods, are also important in managing gout and reducing serum uric acid levels. Additionally, medications like allopurinol or febuxostat may be prescribed to lower uric acid production, or probenecid to help the kidneys eliminate more uric acid 1. During acute gout attacks, anti-inflammatory medications such as colchicine, NSAIDs, or corticosteroids may be prescribed 1.
From the FDA Drug Label
The upper limit of normal is about 7 mg/dL for men and postmenopausal women and 6 mg/dL for premenopausal women. A serum uric acid level that requires medical attention is not explicitly stated, but levels above the upper limit of normal, which is 7 mg/dL for men and postmenopausal women and 6 mg/dL for premenopausal women, may necessitate medical evaluation and possible intervention 2.
From the Research
Serum Uric Acid Levels Requiring Medical Attention
- Serum uric acid levels greater than or equal to 7 mg/dL have been associated with increased risk of all-cause and cardiovascular disease mortality 3
- Levels greater than or equal to 8 mg/dL without overt cardiovascular disease risk factors have been significantly associated with all-cause and cardiovascular disease mortality 3
- The American College of Rheumatology recommends a therapeutic target of serum urate concentration (sUA) <6 mg/dL, or even lower (≤5 mg/dL) in patients with large deposits 4
- Achieving serum uric acid levels less than or equal to 6.0 mg/dL has been associated with improved renal function, as measured by serum creatinine 5
Uric Acid Level Targets for Treatment
- A target serum uric acid level of <6 mg/dL is recommended for patients with gout 4, 6
- For patients with large deposits, a target level of ≤5 mg/dL is recommended 4
- Reducing serum uric acid levels to <6 mg/dL has been shown to slow renal function decline in patients with gout 7
Association Between Uric Acid Levels and Renal Function
- High uric acid levels have been associated with increased risk of renal decline 7, 3, 5
- Reducing serum uric acid levels has been shown to preserve renal function in patients with gout 7
- Achieving serum uric acid levels less than or equal to 6.0 mg/dL has been associated with improved renal function, as measured by serum creatinine 5