Aldosterone, 24‑Hour Urine
Use
Assessment of aldosterone production over a 24‑hour period, aiding in the evaluation of adrenal cortical function, hypertension (including primary hyperaldosteronism/Conn’s syndrome), and in the investigation of hypokalemia associated with elevated blood pressure.
Special Instructions
A 24‑hour urine collection must be refrigerated during collection; preservative such as acetic or boric acid may be required. Record total volume and collection times on the requisition and label. Aliquot urine into a screw‑cap plastic container after thorough mixing.
Limitations
Urinary aldosterone measurements in isolation may have limited diagnostic value for hyperaldosteronism and often require correlation with additional clinical and biochemical parameters.
Methodology
Mass Spectrometry
Biomarkers
Result Turnaround Time
4-10 days
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
10 mL aliquot from 24‑hour collection
Minimum Volume
Not provided
Container
24‑hour plastic urine collection container
Collection Instructions
Collect 24‑hour urine, refrigerate during collection, mix thoroughly, record total volume, transfer 10 mL aliquot into screw‑cap plastic container.
Patient Preparation
Diet containing ~135 mmol sodium per day for ≥2 weeks (preferably 30 days); avoid diuretics, antihypertensives, cyclic progestational agents, estrogen, licorice.
Storage Instructions
Refrigerate aliquot; transport refrigerated.
Causes for Rejection
Incomplete 24‑hour collection; unadjusted/low pH (<2) in original container; missing preservative when required.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
Other tests from different labs that may be relevant