From the Guidelines
Answer to the Question
Serum uric acid levels can indeed be normal in acute gouty arthritis, as stated by the EULAR evidence-based recommendations for gout [ 1 ].
Key Points
- Many people with hyperuricaemia do not develop gout, and during acute attacks, serum levels may be normal [ 1 ].
- Serum uric acid (SUA) levels have limited diagnostic value, especially during an acute attack of gout, as they can be temporarily lowered due to increased renal excretion or behave as a negative acute phase reactant [ 1 ].
- Some patients may have normal SUA levels at the time of investigation, even with MSU crystal-proven gout [ 1 ].
- The definition of hyperuricaemia varies between populations, and men usually have higher levels of SUA than women [ 1 ].
- A raised SUA level is a major risk factor for gout, but many people with high SUA levels do not have gout, and conversely, individual patients who present with MSU crystal-proven gout may have normal SUA levels [ 1 ].
Clinical Implications
- Normal serum uric acid levels do not rule out gout: A normal serum uric acid level, for example, 5.5 mg/dL, does not exclude the diagnosis of gout, especially during an acute attack [ 1 ].
- Consider other diagnostic factors: Clinicians should consider other diagnostic factors, such as clinical manifestations, synovial fluid examination, and medical history, to diagnose gout accurately [ 1 ].
- Monitor and adjust treatment: Treatment should be adjusted according to the individual patient's needs, and monitoring of serum uric acid levels and renal function may be necessary to optimize treatment [ 1 ].
From the Research
Serum Uric Acid Levels in Acute Gouty Arthritis
- Serum uric acid levels can be normal in acute gouty arthritis, as reported in several studies 2, 3, 4, 5, 6
- A study found that 63.3% of patients with acute gout attack had normal serum uric acid levels 2
- Another study reported that 11%-49% of patients with acute gout have normal serum uric acid levels 3
- A retrospective cohort study found that 39.8% of gout patients had normouricemia during an acute attack 4
- Research suggests that normal serum uric acid levels during an acute gout attack do not exclude the diagnosis of gout 2, 6
- The frequency of normal serum uric acid levels during acute gouty attacks has been reported to be as high as 34.92% in some studies 5
Factors Associated with Normal Serum Uric Acid Levels
- Increased inflammatory activity has been observed in patients with normal serum uric acid levels during an acute gout attack 2, 4
- Renal excretion is a potential cause of decreased serum uric acid during acute gout 5
- Patients taking chronic allopurinol were more likely to have lower serum uric acid levels at baseline compared to those not taking chronic allopurinol 6
- Postsurgical gout, hemodialysis initiation, and preserved renal function have been associated with normouricemia during an acute gout attack 4