Hyperuricemia is defined as elevated levels of uric acid (≥7 mg/dL) in the blood and may be caused by either urate overproduction or underexcretion.
Uric acid is produced as the end product of purine nucleotide degradation. Hypoxanthine and xanthine are the intermediates which are converted to uric acid via the enzyme xanthine oxidase. Uric acid is mostly excreted via the kidneys, the remainder being excreted intestinally, but up to 90% is resorbed via the transporters URAT1 and GLUT9 in the kidneys 1,2. Hyperuricemia may result from urate underexcretion, overproduction or a combination of both.
- underexcretion 3:
No radiological features are specific for hyperuricemia. Signs of complications of hyperuricemia may be visible (e.g. gout, nephrolithiasis).
Treatment and prognosis
Hyperuricemia is treated by addressing the underlying cause of urate overproduction or underexcretion, xanthine oxidase and URAT1 inhibitors are also commonly used 2. Hyperuricemia is a risk factor for cardiovascular disease and gout 2,3.
- 1. Enomoto A, Kimura H, Chairoungdua A, Shigeta Y, Jutabha P, Cha SH, Hosoyamada M, Takeda M, Sekine T, Igarashi T, Matsuo H, Kikuchi Y, Oda T, Ichida K, Hosoya T, Shimokata K, Niwa T, Kanai Y, Endou H. Molecular identification of a renal urate anion exchanger that regulates blood urate levels. (2002) Nature. 417 (6887): 447-52. doi:10.1038/nature742 - Pubmed
- 2. Gliozzi M, Malara N, Muscoli S, Mollace V. The treatment of hyperuricemia. (2016) International journal of cardiology. 213: 23-7. doi:10.1016/j.ijcard.2015.08.087 - Pubmed
- 3. Erick Prado de Oliveira, Roberto Carlos Burini. High plasma uric acid concentration: causes and consequences. (2012) Diabetology & Metabolic Syndrome. 4 (1): 12. doi:10.1186/1758-5996-4-12 - Pubmed