Aldosterone, 24-Hour Urine
Use
Study of adrenocortical-renin-angiotensin system; adrenal cortical function test; evaluate renal hypertension; diagnose Conn syndrome (primary aldosteronism); evaluate hypokalemia with hypertension
Special Instructions
Instructions for suppression or stimulation tests involving serum aldosterone measurement can be found in the online Endocrine Appendix: Aldosterone Suppression. It is crucial to follow the instructions carefully to ensure accurate test results.
Limitations
Urinary aldosterone measurements alone have limited value in diagnosing hyperaldosteronism. Elevated levels warrant further investigation to confirm or rule out hyperaldosteronism. Factors such as diuretics, antihypertensives, and dietary variations impact aldosterone levels, potentially affecting test interpretation.
Methodology
Mass Spectrometry
Biomarkers
LOINC Codes
- 1764-0
- 1765-7
Result Turnaround Time
4-9 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
10 mL
Minimum Volume
1 mL
Container
Plastic urine container, no preservative
Collection Instructions
Instruct the patient to void at 8 a.m. and discard the specimen. Then collect all urine including the final specimen voided at the end of the 24-hour collection period (i.e., 8 a.m. the next morning) into the plastic urine container. Screw the lid on securely. Transport the specimen promptly to the laboratory. Container must be labeled with patient's full name, date and time collection started, and date and time collection finished. pH must be 4 to 8.
Patient Preparation
If patient is taking diuretics, antihypertensive drugs, cyclic progestational agents, estrogen, or licorice, results for aldosterone may not be interpretable. Patient should be on a diet containing 135 mmol (3 g) sodium per day for at least two weeks and preferably 30 days prior to testing.
Storage Instructions
Refrigerate
Causes for Rejection
Incomplete 24-hour collection; original container with pH <2
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 14 days |