hyperurikemie

Hyperurikémie, or hyperuricemia, is a condition defined by persistently elevated levels of uric acid in the blood. Uric acid is the end product of purine metabolism in humans. Because humans lack the enzyme uricase, uric acid has limited solubility; when concentrations exceed the solubility threshold, crystals may form in joints, soft tissues, or kidneys.

The condition results from either increased production of uric acid, decreased renal excretion, or a combination of both. Risk factors include obesity, metabolic syndrome, renal impairment, certain medications (such as thiazide and loop diuretics, low-dose aspirin, cyclosporine), excessive purine intake (red meat, seafood), alcohol consumption, and high-fructose diets. Hyperuricemia is a major risk factor for gout and uric acid nephrolithiasis and is associated with cardiovascular and renal disease, especially when accompanied by metabolic abnormalities.

Most people with hyperuricemia are asymptomatic. When urate crystals deposit in joints, a gout attack can occur, typically presenting as sudden, painful swelling of a joint (often the first metatarsophalangeal joint). Chronic hyperuricemia can lead to tophi formation and joint damage. Urate crystals can also cause kidney stones and, less commonly, lead to chronic kidney disease.

Diagnosis relies on serum uric acid measurement, with interpretation guided by clinical context. A single elevated value does not establish disease on its own; assessment for gout, kidney stones, and comorbid conditions is important. In some cases, 24-hour urinary uric acid excretion or imaging for crystal deposition may be used.

Management focuses on lowering uric acid to target levels, treating gout flares, and addressing contributing factors. Lifestyle measures include weight management, reduced intake of purines and alcohol, hydration, and limiting fructose. Pharmacologic options include xanthine oxidase inhibitors (allopurinol, febuxostat), uricosurics in appropriate patients, and, for refractory cases or tumor lysis risk, recombinant uricase therapies. Regular monitoring of uric acid levels and renal function guides treatment.