Catecholamines - urine

Definition

Catecholamines are small substances made by nerve tissue (including the brain) and the adrenal gland.

The major catecholamines are dopamine, norepinephrine, and epinephrine. These substances break down into other substances, which leave your body through your urine.

A urine test can be done to measure the level of catecholamines in your body.

Catecholamines can also be measured with a blood test. See also: Catecholamines - blood

Alternative Names

Dopamine-urine test; Epinephrine-urine test; Adrenalin-urine test; Vanillylmandelic acid (VMA); Urine metanephrine; Normetanephrine; Norepinephrine-urine test; Urine catecholamines; VMA; HVA; Metanephrine; Homovanillic acid (HVA)

How the Test is Performed

For this test, you must urinate into a special bag or container every time you use the bathroom for 24-hour period.

• On day 1, urinate over the toilet into the container or bag when you wake up in the morning. Close the container tightly. Keep it in the refrigerator or a cool place during the collection period.
• Urinate into the special container every time you use the bathroom for the next 24 hours.
• On day 2, urinate into the container in the morning again when you wake up.
• Label the container with your name, the date, the time of completion, and return it as instructed.

For an infant:

Thoroughly wash the area around the urethra (the hole where urine flows out). Open a urine collection bag (a plastic bag with an adhesive paper on one end).

• For males, place the entire penis in the bag and attach the adhesive to the skin.
• For females, place the bag over the two folds of skin on either side of the vagina (labia). Put a diaper on the baby (over the bag).

Check the infant frequently, and change the bag after the infant has urinated. Empty the urine from the bag into the container provided by your doctor.

Because lively infants can cause the bag to move, this procedure may take a couple of attempts. You may need extra collection bags.

When finished, label the container and return it as instructed.

How to Prepare for the Test

Stress and vigorous exercise may affect the test results.

Foods that can increase urinary catecholamines include coffee, tea, bananas, chocolate, cocoa, citrus fruits, and vanilla. Avoid these foods for several days before the test.

Certain drugs can also affect the test results. Your health care provider may tell you to stop taking certain medicines before the test. Never stop taking medicine without first talking to your doctor.

The following drugs can increase catecholamine measurements:

• Alcohol
• Aminophylline
• Amphetamines
• Buspirone
• Caffeine
• Cocaine
• Decongestants such as phenylephrine or pseudoephedrine
• Drug withdrawal
• Levodopa
• Methyldopa
• Phenothiazines
• Reserpine
• Tricyclic antidepressants

Drugs that can decrease catecholamine measurements include:

• Clonidine
• Disulfiram
• Guanethidine
• MAO inhibitors
• Salicylates

How the Test Will Feel

The test involves only normal urination, and there is no discomfort.

Why the Test is Performed

The test is usually done to diagnose an adrenal gland tumor called pheochromocytoma. It may also be used to diagnose neuroblastoma. Urine catecholamine levels are increased in most persons with neuroblastoma.

The urine test for catecholamines may also be used to monitor those who are receiving treatment for these conditions.

Normal Results

All of the catecholamines are broken down into inactive substances that appear in the urine:

• Dopamine becomes homovanillic acid (HVA)
• Norepinephrine becomes normetanephrine and vanillylmandelic acid (VMA)
• Epinephrine becomes metanephrine and VMA

The following normal values are the amount of the substance found in the urine over a 24-hour period:

• Dopamine: 65 - 400 micrograms (mcg)/24 hours
• Epinephrine: 0.5 - 20 mcg/24 hours
• Metanephrine: 24 - 96 mcg/24 hours (some laboratories give the range as 140 - 785 mcg/24-hours)
• Norepinephrine: 15 - 80 mcg/24 hours
• Normetanephrine: 75 - 375 mcg/24 hours
• Total urine catecholamines: 14 - 110 mcg/24 hours
• VMA: 2 - 7 milligrams (mg)/24 hours

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

What Abnormal Results Mean

Elevated levels of urinary catecholamines may indicate:

• Acute anxiety
• Ganglioblastoma (very rare)
• Ganglioneuroma (very rare)
• Neuroblastoma (rare)
• Pheochromocytoma (rare)
• Severe stress

The test may also be performed for:

• Multiple endocrine neoplasia (MEN) II

Risks

There are no risks.

Considerations

Several foods and drugs, as well as physical activity and stress, can affect the accuracy of this test.

References

Young WF. Adrenal medulla, catecholamines, and pheochromocytoma. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 246.

Young WF. Endocrine hypertension. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 16.

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