ALDOSTERONE/RENIN ACTIVITY RATIO
- ALDOSTERONE/RENIN ACTIVITY RATIO
- Start Date
- Expiration Date
- Aldosterone Renin Ratio (ARR)
- CPT Codes
- 82088, 84244
- Reference Test
2.0 ml (Two 1.0ml aliquots)
- Transport Info
Centrifuge and immediately transfer plasma to two (2) separate plastic tubes (1.0ml in each)
CRITICAL FROZEN – Separate specimens must be submitted when multiple tests are ordered
- Fasting Required?
- 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
Quantitative Radioimmunoassay (RIA)
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).