Lhyperuricémie

Hyperuricemia, or l'hyperuricémie in French, is a biochemical condition characterized by persistently elevated serum uric acid levels. Uric acid is produced from purine metabolism and is primarily excreted by the kidneys; when production exceeds excretion, serum levels rise.

Causes may be primary (idiopathic) or secondary to disease or drugs. Primary hyperuricemia often involves reduced renal urate excretion due to genetic variants in renal transporters. Secondary causes include renal insufficiency, metabolic syndrome, obesity, diabetes, hypertension, high-purine diet, alcohol use (especially beer), fructose-sweetened beverages, and medications such as thiazide and loop diuretics, niacin, and certain agents. Age and sex influence risk; men have higher prevalence, while risk in women increases after menopause.

Clinical significance: most individuals are asymptomatic. Hyperuricemia is associated with gout, a condition marked by recurrent joint inflammation due to monosodium urate crystals; it can also cause uric acid nephrolithiasis and, less commonly, urate nephropathy. Some observational data link hyperuricemia with kidney disease progression and cardiovascular risk, though causality remains debated.

Diagnosis: hyperuricemia is defined by elevation of serum uric acid concentration, often above 7 mg/dL in men or 6 mg/dL in women, with thresholds varying by guideline. In asymptomatic individuals, measurement is guided by risk factors. Evaluation may include assessment of kidney function, 24-hour urine uric acid excretion in selected cases, and imaging if gout or stones are suspected.

Management: asymptomatic hyperuricemia typically does not require treatment. Focus is on managing comorbidities and lifestyle: weight reduction, reduced intake of purine-rich foods, limited alcohol, and adequate hydration. Urate-lowering therapy (eg, xanthine oxidase inhibitors such as allopurinol or febuxostat; uricosurics such as probenecid) is reserved for patients with recurrent gout, tophaceous disease, or urate nephrolithiasis. Pegloticase is used for refractory cases. Therapy aims to maintain target serum uric acid levels with monitoring and flare prophylaxis during initiation.