Urea
From Health Facts
Latest Edit: Hector 2014-03-21 (EDT)
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Urea is a nitrogenous compound that is the final breakdown product of purine catabolism. Levels of uric acid in the urine are helpful in evaluating uric acid metabolism in gout and for assessing hyperuricosuria in renal calculus formation. This test is also useful in identifying persons at risk for stone formation.[1], [2]
Discussion
- Uric acid is produced primarily in the liver.
- Urinary excretion or uric acid depends on uric acid levels in the blood, along with glomerular filtration and tubular secretion of uric acid into the urine.
- Seventy-five percent of uric acid is excreted via the kidneys, and 25% by way of the intestinal tract.
- Elevated uric acid levels (hyperuricemia) may be indicative of gout, a form of arthritis caused by deposition of uric acid crystals in periarticular tissue.
Patient Preparation
- No special diet is required
- Factors which can cause increased levels:
- recent use of radiographic contrast agents
- Drugs: alcohol, antiinflammatory preparations, salicylates, thiazide diuretics, vitamin C, and warfarin
Clinical Implications
High levels indicate:
- Gout
- Metastatic cancer
- Multiple myeloma
- Leukemias
- Cancer chemotherapy
- High-purine diet
- Uricosuric acid
- Lead toxicity
Low levels indicate:
- Kidney disease
- Eclampsia
- Chronic alcohol ingestion
- Acidosis (ketotic [diabetic or starvation], lactic)
Associated Tests
References
- ↑ Pagana Kathleen D, Pagana Timothy J (2006) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby.
- ↑ Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain.
