Aldosterone
(ALD)

Sample type: -

1. Serum or plasma (heparin)

2. Urine (24-hour)

Uses: -

1. Diagnosis of primary hyperaldosteronism.

2. Differential diagnosis of fluid and electrolyte disorders.

3. Assessment of adrenal aldosterone production

Precautions: -

1. If patient is taking diuretics, antihypertensive drugs, cyclic progestational agents, estrogen, or licorice, results for aldosterone may not be interpretable.

2. 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.

3. The patient should be taken off medications for at least three weeks prior to sample collection. Dietary sodium levels during the period prior to testing can affect aldosterone levels. Reference intervals are based on the clinician’s verification that the patient has been on a normal sodium diet.

Interfere factor: -

1. Values are increased by upright posture.

2. Recently administered radioactive medications affect test outcomes.

3. Heparin therapy causes levels to fall.

4. Thermal stress, late pregnancy, and starvation cause levels to rise.

5. Aldosterone levels decrease with age.

6. Many drugs—diuretics, antihypertensives, progestogens, estrogens, and licorice—should be terminated 2–4 weeks before test.

Pre analytical errors: -

• Incomplete 24-hour collection; original container with pH <2.

• Have patient resume hard activities and diet.

• Take the sample in wrong tube.

Corrective action: -

• Ensure that the patient’s diet for 2 weeks before the test and should include 3 g/day (135 mEq/L/day) of sodium.

• Use red-top tube, gel-barrier tube, or lavender-top (EDTA) tube.

Post analytical errors: -

1. Very high result.

2. Send the result for wrong patient.

Corrective action: -

1. Interpret test results and monitor appropriately for aldosteronism and aldosterone deficiency.

2. Be carful with labeling and submission of the result.

Reference range: -

For serum or plasma: -

• Normal (In upright position)

• Adults: 7–30 ng/dL or 0.19–0.83 nmol/L

• Adolescents: 4–48 ng/dL or 0.11–1.33 nmol/L

• Children: 5–80 mg/dL or 0.14–2.22 nmol/L

• Low-sodium diet: values 3–5 times higher

For 24 hours urine: -

- Pediatric:

− 0 to 3 days: 0.00−5.00 μg/24 hours

− 4 days to 10 years: 0.00−8.00 μg/24 hours

− >10 years: 0.00−19.00 μg/24 hours

- Adults:

− Low sodium intake: 20.00−80.00 μg/24 hours

− Normal sodium intake: 0.00−19.00 μg/24 hours

− High sodium intake: 0.00−12.00 μg/24 hour