ALDOSTERONE/RENIN ACTIVITY RATIO

Code
000.0000
Name
ALDOSTERONE/RENIN ACTIVITY RATIO
Category
None
Department
Send-Out
Start Date
Expiration Date
Synonyms
Aldosterone Renin Ratio (ARR)
CPT Codes
82088, 84244
Site
SBMF
Reference Test
30074
ATLAS Test Code

Specimen Information

Type

(Gold SST or Red Top) AND Lavender Top

Volume

1.0 ml Serum AND 2ml EDTA Plasma

Transport Info

Centrifuge and immediately transfer plasma from Lavender Tube to a separate plastic tube.

Transfer 1ml SERUM from Gold or Red Top to separate plastic tube.

Frozen

CRITICAL FROZEN – Separate specimens must be submitted when multiple tests are ordered

Fasting Required?
False
Patient Instructions

Discontinue diuretics, antihypertensive drugs, cyclic progestogens, estrogens, and licorice for at least 2 weeks (preferred 4 weeks) prior to sample collection
Patients should be on normal salt diet: 3.0 grams of sodium a day for 2-4 weeks prior to sampling

Supine specimen: Draw before patient arises in morning
Upright specimen: Draw from patient who has been upright at least 2 hours

Reference Range

See Report

Methodology

Quantitative Radioimmunoassay (RIA)

Clinical Significance

Differential diagnosis of hyperaldosteronism in combination with the determination of aldosterone and functional tests; Diagnosis of isolated mineralocorticoid deficiency; Detection of renin-producing tumors
Diagnosis of malignant hypertension

Renin is produced in the juxtaglomerular cells of the kidney. These cells are innervated by sympathetic nerves. Renin secretion is increased when blood pressure in the arterioles is low and by sympathetic stimulation. Sympathetic stimulation occurs under circumstances of physical stress. Renin angiotensin system (RAS) is activated in hemorrhagic and cardiogenic shock, after fluid loss by diarrhea and the use of diuretics, and in edematogenic conditions such as liver or kidney disease. Renin is substrate, angiotensinogen, angiotensin I, and angiotensin II, specific. Measurement of renin activity is therefore a good index of RAS activity.

The secretion of renin is affected by sodium load and the intake of potassium. Renin levels are also affected by the following biological factors: body posture (upright >supine), physical activity (increased levels), and diurnal variation (highest in the morning and lowest in the late afternoon).

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