Urine Test for Oxalates.
Urine test for oxalates and other salts is a biochemical study aimed at determining the concentration of oxalic acid salts (oxalates) and other mineral compounds in 24-hour urine. This test helps diagnose metabolic disorders associated with increased oxalate production and assesses the risk of urolithiasis.
Indications for testing:
- Suspected urolithiasis, especially with symptoms such as renal colic, lower back pain, hematuria (blood in urine).
- Detection and monitoring of hyperoxaluria — a condition with excessive oxalate formation and excretion, including primary (genetic) and secondary forms.
- Disorders of calcium metabolism (hypercalciuria), osteoporosis, parathyroid gland pathologies.
- Gastrointestinal diseases (inflammatory bowel diseases, malabsorption syndrome, chronic pancreatitis).
- Diabetes mellitus, hyperparathyroidism, sarcoidosis, and other systemic diseases.
- Monitoring the effectiveness of therapy and diet in hyperoxaluria and urolithiasis.
- Ethylene glycol poisoning and prolonged high-dose vitamin C intake.
Features of the test:
- 24-hour urine is used to obtain the most accurate data on oxalate concentration.
- Urine collection must be done properly: the first morning portion is discarded, then all urine is collected over 24 hours into a clean container following hygiene rules.
- Urine is mixed, total volume measured, and a sample taken for laboratory analysis.
- The analysis is conducted by enzymatic colorimetric or other biochemical methods.
Interpretation of results:
- Normal oxalate level in 24-hour urine is approximately 20–50 mg in adults and 10–40 mg in children.
- Increased oxalate levels indicate hyperoxaluria and a higher risk of oxalate kidney stone formation.
- Test results are evaluated considering clinical context, comorbidities, and patient diet.
Thus, urine testing for oxalates and other salts is an important diagnostic tool for detecting and monitoring metabolic disorders that contribute to urolithiasis and other kidney pathologies.