Why Uric Acid is Checked in CKD Patients
Uric acid should be checked in CKD patients primarily to identify therapeutic implications for gout management, assess cardiovascular and metabolic comorbidities, and guide medication selection—not to treat asymptomatic hyperuricemia, which does not slow CKD progression. 1
Primary Reasons for Monitoring Uric Acid in CKD
Therapeutic Decision-Making for Gout
- Hyperuricemia and gout are extremely common in CKD, with gout present in 25% and hyperuricemia in 60% of CKD patients 2
- Identifying CKD stage is critical because it determines which urate-lowering medications are safe to use 3
- Patients with moderate-to-severe CKD (stage ≥3) should not receive uricosuric agents like probenecid or benzbromarone 3
- For symptomatic gout in CKD stages 3-4, xanthine oxidase inhibitors (allopurinol starting at ≤50 mg/day) are preferred over uricosurics 1
- Colchicine and NSAIDs must be avoided in severe renal impairment, making uric acid measurement essential for safe anti-inflammatory selection 3
Assessment of Associated Comorbidities
- Hyperuricemia serves as a marker for cardiovascular disease, heart failure, stroke, peripheral arterial disease, and diabetes—all of which are independent risk factors for mortality in CKD patients 3
- Large epidemiological studies demonstrate that both hyperuricemia and gout are independent risk factors for cardiovascular death 3
- The bidirectional relationship between CKD and hyperuricemia makes monitoring important for identifying patients at highest risk for progression 4
Medication-Induced Hyperuricemia Detection
- Diuretics (thiazides and loop diuretics) are among the most common medication-related causes of elevated uric acid in CKD through volume depletion and enhanced tubular reabsorption 5
- Calcineurin inhibitors in transplant recipients impair renal uric acid excretion 5
- Identifying medication-induced hyperuricemia allows for potential therapeutic adjustments when clinically appropriate 5
What NOT to Do Based on Uric Acid Results
Do Not Treat Asymptomatic Hyperuricemia
- KDIGO guidelines explicitly recommend NOT initiating uric acid-lowering therapy for asymptomatic hyperuricemia, as it does not delay CKD progression 1
- A 2022 JAMA Network Open study of 269,651 patients found that uric acid-lowering therapy in patients with normal kidney function was associated with higher risk of incident eGFR <60 mL/min/1.73 m² (SHR 1.15,95% CI 1.10-1.20) and incident albuminuria (SHR 1.05,95% CI 1.01-1.09) 6
- Treatment of hyperuricemia in patients with preexisting CKD has not been shown to improve kidney outcomes 6
Critical Monitoring Parameters
- Uric acid should be measured in parallel with eGFR calculation at diagnosis and monitored regularly 3
- The frequency of monitoring depends on CKD stage severity, with higher-stage CKD requiring more frequent assessment 3
- Serum uric acid should be monitored particularly when initiating diuretics or during periods of volume depletion 5
Common Pitfalls to Avoid
- Do not assume all hyperuricemia in CKD is simply due to reduced clearance—actively assess for modifiable dietary factors (purine-rich foods, alcohol, high-fructose corn syrup), medication contributions, and volume status 5
- Never use NSAIDs for pain management in CKD patients, as they worsen both kidney function and hyperuricemia 1, 5
- Do not rely on uric acid levels alone for gout diagnosis—levels may be paradoxically normal or low during acute attacks due to increased renal excretion 7
- Avoid treating based solely on laboratory values without considering the clinical context of symptoms, stone history, or documented gout 7