Hyperuricemia Medical Services in China

Hyperuricemia is a metabolic disorder characterized by elevated serum uric acid (SUA) levels—defined as >6.8 mg/dL (>405 µmol/L) in men and >5.7 mg/dL (>340 µmol/L) in women—reflecting an imbalance between uric acid production and renal excretion. Uric acid is the end product of purine metabolism in humans; unlike most mammals, humans lack uricase, making them prone to urate accumulation. Pathogenesis involves either overproduction (e.g., due to increased purine synthesis, high dietary purine intake, or enzymatic defects like HGPRT deficiency), underexcretion (accounting for ~90% of cases, often linked to reduced URAT1 or GLUT9 transporter activity in proximal renal tubules), or a combination. Genetic factors—including polymorphisms in SLC2A9, ABCG2, and SLC22A12—significantly influence urate handling. Secondary causes include chronic kidney disease, hypertension, obesity, metabolic syndrome, diuretic use (especially thiazides and loop diuretics), alcohol consumption (particularly beer and spirits), and malignancy-related tumor lysis. Epidemiologically, hyperuricemia affects approximately 14–24% of adults globally, with rising prevalence in China (13.3% overall, up to 21.6% in urban males aged 40–60), driven by aging, dietary Westernization, sedentary lifestyles, and increasing rates of obesity and CKD. Key modifiable risk factors include high-fructose corn syrup intake (e.g., sugary beverages), red meat and seafood consumption, excessive alcohol, insulin resistance, and chronic low-grade inflammation. Non-modifiable risks include male sex, postmenopausal status, family history, and certain ethnic backgrounds (e.g., East Asian and Pacific Islander populations show higher baseline SUA). Although often asymptomatic, persistent hyperuricemia substantially elevates the risk of gout (acute inflammatory arthritis), uric acid nephrolithiasis, chronic kidney disease progression, cardiovascular morbidity (including hypertension, coronary artery disease, and heart failure), and metabolic dysfunction. Quality of life is frequently impaired—even before gout onset—due to anxiety about flare unpredictability, dietary restrictions limiting social engagement, chronic fatigue, sleep disruption from nocturnal flares, and stigma associated with visible tophi or recurrent joint swelling. Untreated, it contributes to long-term disability, work absenteeism, and reduced physical function. Early detection via routine serum uric acid screening—especially in patients with hypertension, diabetes, CKD, or metabolic syndrome—is critical for timely intervention and prevention of irreversible organ damage.

Hyperuricemia—defined as serum uric acid (SUA) concentration exceeding 6.8 mg/dL (405 µmol/L), the physiological saturation threshold for monosodium urate—represents a key metabolic disorder managed primarily within Endocrinology. While often asymptomatic, chronic hyperuricemia predisposes individuals to gouty arthritis, uric acid nephrolithiasis, chronic kidney disease (CKD), hypertension, insulin resistance, and cardiovascular morbidity. Management is stratified according to SUA level, symptom status (asymptomatic vs. gout or nephrolithiasis), comorbidities (e.g., CKD stage, diabetes, heart failure), and urinary uric acid excretion profile (underexcretors vs. overproducers). A comprehensive, evidence-based approach integrates conservative measures, pharmacotherapy, and, rarely, surgical intervention.

Conservative treatment forms the cornerstone of long-term management and must be initiated in all patients, regardless of pharmacologic indication. Dietary modification emphasizes reduction of purine-rich foods—including red meat, organ meats, shellfish, and yeast extracts—while encouraging low-fat dairy, cherries (anthocyanin-mediated xanthine oxidase inhibition), coffee (dose-dependent uricosuric effect), and adequate hydration (>2 L/day to maintain urine output >2 L/day and prevent uric acid crystallization). Alcohol intake—particularly beer (high in purines and ethanol-induced lactic acidosis impairing renal urate excretion) and spirits—must be strictly limited; wine may be consumed in moderation if tolerated. Fructose-sweetened beverages and high-fructose corn syrup are strongly discouraged due to hepatic fructokinase-driven ATP depletion and subsequent uric acid generation. Weight loss—achieved via caloric restriction and aerobic exercise—is recommended for overweight or obese individuals (BMI ≥24 kg/m² in Asian populations), with even 5–10% weight reduction shown to lower SUA by 0.5–1.0 mg/dL. Concurrent management of metabolic comorbidities is essential: optimizing glycemic control in diabetes, using SGLT2 inhibitors (which confer mild uricosuric effects), selecting antihypertensives that do not elevate SUA (e.g., losartan, calcium channel blockers) while avoiding diuretics (especially thiazides and loop diuretics) unless absolutely necessary and closely monitored.

Pharmacologic therapy is indicated when SUA remains ≥9.0 mg/dL despite lifestyle optimization; in patients with recurrent gout flares (≥2/year), tophi, radiographic joint damage, urolithiasis, or CKD stage ≥2 (eGFR <90 mL/min/1.73m²). First-line urate-lowering therapy (ULT) in China and globally is allopurinol, a xanthine oxidase inhibitor (XOI). Initiated at 100 mg/day (50 mg/day in CKD stage 3–4), titrated upward every 2–4 weeks to achieve target SUA <6.0 mg/dL (or <5.0 mg/dL in severe gout), allopurinol is cost-effective, well-studied, and safe with appropriate HLA-B*58:01 screening (mandatory in Han Chinese populations due to 6–8% carrier frequency and markedly increased risk of severe cutaneous adverse reactions including SJS/TEN). Febuxostat, a non-purine XOI, serves as first-line alternative in patients with allopurinol intolerance or contraindication, particularly those with moderate CKD; however, cardiovascular safety requires careful assessment per FDA and EMA guidance. For underexcretors (fractional excretion of uric acid <5.5%), uricosurics—including benzbromarone (highly effective, potent, and widely used in China despite restricted availability elsewhere due to rare hepatotoxicity) and lesinurad (used adjunctively)—are valuable. Benzbromarone is favored in China for its superior efficacy in lowering SUA compared to probenecid and sulfinpyrazone, especially in CKD stages 2–3, though liver enzyme monitoring is mandatory. Topiroxostat, a novel XOI approved in China, offers once-daily dosing and favorable renal safety. Colchicine (0.5–0.6 mg once or twice daily) or low-dose NSAIDs are prescribed prophylactically during ULT initiation for at least 6 months to prevent gout flares triggered by crystal shedding.

Surgical treatment plays an extremely limited role and is reserved exclusively for complications. Tophaceous gout refractory to maximal medical therapy may necessitate surgical tophi debulking—typically for large, ulcerating, infected, or mechanically disabling deposits (e.g., compressing nerves or tendons). Procedures include curettage, excision, or arthroscopic debridement, often combined with joint reconstruction in advanced cases. Uric acid nephrolithiasis unresponsive to medical dissolution (alkalinization + hydration) or causing obstruction/infection may require ureteroscopy with laser lithotripsy or percutaneous nephrolithotomy. Importantly, surgery does not replace ULT; postoperative SUA control remains critical to prevent recurrence.

China offers distinct advantages in hyperuricemia care. First, national clinical guidelines (CSE 2023, CDS 2020) emphasize early, aggressive ULT targeting SUA <5.0 mg/dL in severe gout—more stringent than many Western recommendations—and integrate HLA-B*58:01 pre-screening into routine practice, significantly reducing life-threatening adverse drug reactions. Second, China’s robust domestic pharmaceutical industry ensures broad access to high-quality, affordable generics (allopurinol, benzbromarone) and novel agents (topiroxostat, ulodesine) at substantially lower costs than in high-income countries. Third, integrated traditional Chinese medicine (TCM) modalities—such as acupuncture for pain modulation during flares and standardized herbal formulas (e.g., Si Miao San derivatives) studied for anti-inflammatory and mild uricosuric effects—are increasingly incorporated into multidisciplinary protocols under rigorous quality control. Fourth, China’s tiered healthcare system enables seamless referral from community health centers (for screening, lifestyle counseling, and initial ULT) to tertiary endocrine centers (for complex cases, genetic testing, and biologic therapies under investigation).

Recovery and long-term maintenance hinge on adherence and monitoring. Patients should undergo SUA measurement every 2–4 weeks during ULT titration until target is sustained for ≥3 months, then quarterly thereafter. Renal function (serum creatinine, eGFR, urinalysis), liver enzymes (especially with benzbromarone or febuxostat), and complete blood count must be tracked regularly. Education on flare recognition and self-management—including immediate colchicine use at symptom onset—is vital. Psychological support addresses stigma associated with gout and chronic disease burden. Annual cardiovascular risk assessment (blood pressure, lipid panel, fasting glucose, carotid ultrasound) is recommended given the strong epidemiologic links between hyperuricemia and atherosclerosis. Ultimately, successful management transforms hyperuricemia from a biochemical abnormality into a modifiable cardiovascular-metabolic risk factor—requiring lifelong commitment to integrated, patient-centered care.