Aldosterone with Sodium, 24 Hour, Urine
Use
Investigating primary aldosteronism (e.g., adrenal adenoma/carcinoma and adrenal cortical hyperplasia) and secondary aldosteronism (e.g., renovascular disease, salt depletion, potassium loading, cardiac failure with ascites, pregnancy, Bartter syndrome) in conjunction with urine sodium levels.
Special Instructions
Patient preparation includes discontinuation of spironolactone (Aldactone) for 4 to 6 weeks before testing. For collection, add 25 mL of 50% acetic acid (15 mL for children under 5 years) at start to achieve pH ~2–4. Collect 24-hour urine, record total volume, then aliquot 5 mL labeled 'Aldosterone' and 5 mL labeled 'Sodium'. Use Sarstedt Aliquot Tube 5 mL (T914); complete and send Renal Diagnostics Test Request (T830) if not ordered electronically. Useful PDFs include 'Urine Preservatives‑Collection and Transportation for 24‑Hour Urine Specimens' and 'Renin‑Aldosterone Studies'.
Limitations
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration. Urinary aldosterone excretion greater than 12 mcg/24 hours is consistent with hyperaldosteronism; if 24‑hour urinary sodium exceeds 200 mmol, urinary aldosterone should be less than 10 mcg. Interpretation may be confounded by ACE inhibitor use (may falsely elevate plasma renin activity) and treatment with spironolactone interferes with interpretation.
New York Approved
Methodology
Mass Spectrometry (LC‑MS/MS)
Biomarkers
LOINC Codes
- 94871-1
- 1765-7
- 2956-1
- 13362-9
- 3167-4
- 21525-1
Result Turnaround Time
2-8 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
10 mL
Minimum Volume
2 mL
Container
Sarstedt Aliquot Tube 5 mL (T914), plastic, 5‑mL tubes
Collection Instructions
Add 25 mL of 50% acetic acid (15 mL for children <5 years) at start; collect 24‑hour urine, record total volume; aliquot 5 mL labeled Aldosterone and 5 mL labeled Sodium.
Patient Preparation
Discontinue spironolactone (Aldactone) for 4 to 6 weeks before testing.
Causes for Rejection
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 14 days |