Abstract
Uric acid nephrolithiasis is characteristically a manifestation of a systemic metabolic disorder. It has a prevalence of about 10% among all stone formers, the third most common type of kidney stone in the industrialized world. Uric acid stones form primarily due to an unduly acid urine; less deciding factors are hyperuricosuria and a low urine volume. The vast majority of uric acid stone formers have the metabolic syndrome, and not infrequently, clinical gout is present as well. A universal finding is a low baseline urine pH plus insufficient production of urinary ammonium buffer. Persons with gastrointestinal disorders, in particular chronic diarrhea or ostomies, and patients with malignancies with a large tumor mass and high cell turnover comprise a less common but nevertheless important subset. Pure uric acid stones are radiolucent but well visualized on renal ultrasound or computer tomography. A 24 h urine collection for stone risk analysis provides essential insight into the pathophysiology of stone formation and may guide therapy. Management includes a liberal fluid intake and dietary modification. Potassium citrate to alkalinize the urine to a goal pH between 6 and 6.5 is essential, as undissociated uric acid deprotonates into its much more soluble urate form.
Original language | English (US) |
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Pages (from-to) | 207-217 |
Number of pages | 11 |
Journal | Clinical Reviews in Bone and Mineral Metabolism |
Volume | 9 |
Issue number | 3-4 |
DOIs | |
State | Published - Dec 2011 |
Keywords
- Acid urine
- Alkaline
- Ammonium
- Gout
- Hyperuricosuria
- Metabolic syndrome
- PH
- Potassium citrate
- Uric acid nephrolithiasis
- Urine buffer
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Orthopedics and Sports Medicine
- Endocrinology