Aldosterone / Direct Renin Ratio (ADRR)

Specimen Required

3cc Clotted & 3cc EDTA

Fasting Required

Purpose of the Test

To see if your aldosterone or renin levels are abnormal; to detect hyperaldosteronism (overproduction of aldosterone) or hypoaldosteronism (underproduction of aldosterone)

When this test is required

Aldosterone and renin tests are commonly requested together. High blood pressure together with a low potassium concentration within the bloodstream usually leads the doctor to request these two tests. Aldosterone levels are sometimes used in people suspected of having poor adrenal function. Some doctors use aldosterone and renin levels to point to the likely treatments that will be effective in persons with high blood pressure.

What the Test Detects

Aldosterone is a hormone which regulates the retention of sodium (salt) and water by the kidney and also regulates the removal of potassium. It plays an important role in the control of blood pressure.Aldosterone is produced by the adrenal glands which are located at the top of each kidney. Its production is stimulated by a complex process that includes several other “hormones”, the most important of these being renin and angiotensin II. Renin, produced by the kidney, stimulates production of angiotensin II in the bloodstream. Angiotensin II then regulates the release of aldosterone. Normally when renin increases, aldosterone increases; when renin is low, aldosterone decreases.See MoreSee Less

Preparation for the Test

You may be asked to adhere to an unrestricted salt diet prior to the test or to temporarily discontinue one or more medications. The amount of salt in the diet and medicines, such as over-the-counter pain relievers can affect the test results. Medicines of the non-steroid class (such as Ibuprofen) and beta blockers can increase the ratio of aldosterone to renin giving a false positive, whereas diuretics (water pills),angiotensin-converting enzyme (ACE) inhibitors and calcium channel blockers can reduce the ratio giving a false negative result. Oral contraceptives can affect the test results by falsely raising the ratio but this depends on the assay method used for renin in the laboratory. Many of these drugs are used to treat high blood pressure. Your doctor will tell you if you should change the amount of sodium (salt) you ingest in your diet, your use of diuretics or other medications, or your exercise routine before aldosterone and renin are tested. Your doctor will also want to know if your serum potassium level is low as this would affect the aldosterone level.Please follow any instructions you are given, as this is important to ensure the validity of test results.

Sample Requirements

A blood sample taken from a vein in your arm or a 24-hour urine sample

Additional Notes

As some medicines can affect the aldosterone-renin ratio results your doctor will tell you if you should change your medications before testing. For example beta-blockers and ACE inhibitors should ideally be stopped 2 weeks prior to testing and Spironolactone and other diuretics should ideally be withheld for 6 weeks before testing. If it is necessary to maintain the control of high blood pressure your doctor will prescribe alternative antihypertensive medication that has lesser effects on the aldosterone and renin results. Do not stop taking any medications unless specially advised by your doctor.

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