Urine Vanillylmandelic Acid (VMA)

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Category: Urine hormones and metabolites.
Subcategory: Urine metabolites.
Material studied: Urine.
Estimated cost of test: $37.00.
Patient time for test: 24+ hours.
Reliability of test results: Good.
Available as home self-test? No.
Note: Test evaluates hormonal secretion.

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BEFORE THE TEST

Purpose of test:

• Helps detect pheochromocytoma, tumors and some disorders of the autonomic nervous system.
• Evaluates the function of the adrenal medulla.

Where is test performed?

• Commercial laboratory, hospital, doctor's office.

Who performs test?

• Lab technician, nurse, doctor.

Risks and precautions:

• None.

Patient preparation:

• Activity - Avoid excessive physical exercise and stressful situations during the collection period.
• Diet - Do not eat any food or drink any beverages containing phenolic acid, such as coffee, tea, bananas, citrus fruits, chocolate and vanilla, for 3 days before the test.
• Medicines - Inform the person performing the test if you have recently taken any medications listed under Taking these drugs may affect test results. You may be asked not to take this medication before the test.
• Disrobing - None required.

THE TEST

Sensory factors:

• Seeing - Urine color varies greatly, whether you're healthy or ill. Tell the technician, nurse or doctor if urine appears red, cloudy, smoky or has any other strange appearance or color.
• Smelling - Urine may have a noticeably abnormal odor if it is concentrated. Many drugs and foods affect the smell and other characteristics of urine. Report any unusual odors to the technician, nurse or doctor.
• Feeling - Collecting a urine specimen should not cause pain. If it does, notify the technician, nurse or doctor.
• Other senses (touch, hearing, taste) - Not affected.

Equipment used:

• Sterile urine container.

Description of test:

• Collect a 24-hour urine specimen.
• Refrigerate the specimen, or keep it on ice during the collection period.
• Take urine sample to laboratory for analysis.

AFTER THE TEST

Immediate post-test care:

• None.

Activity after test:

• Resume taking any medications that were withheld before the test.
• Resume normal diet.
• Return to pretest activities right away.

Time before test results available:

• Test requires only a few minutes in the laboratory. Time before results are reported to the doctor or patient varies from a few minutes to a few days.

TEST RESULTS

Test values:

• Test results are determined by spectrophotofluorometry.

Normal values:

• VMA values - 0.7 to 6.8mg/24 hours.

What HIGH or INCREASED may indicate:

• Catecholamine-secreting tumor, such as pheochromocytoma.
• Endocrine disorders.

Taking these drugs may affect test results:

• Aminosalicylic acid (PAS).
• Aspirin.
• Bromsulphalein (BSP).
• Chlorpromazine.
• Clofibrate.
• Glyceryl guaiacolate.
• Guanethidine analogs.
• Imipramine.
• MAO inhibitors.
• Mephenesin.
• Methocarbamol.
• Methyldopa.
• Nalidixic acid.
• Oxytetracycline.
• PSP.
• Penicillin.
• Phenazopyridine.
• Reserpine.
• Sulfa drugs.

Other factors that may affect test results:

• Excessive physical exercise.
• Emotional stress.
• Failure to follow diet restrictions.
• Failure to collect all urine during the test period.
• Failure to store the specimen properly.

From the Complete Guide to Medical Tests by H. Winter Griffith, M.D. © 1988 by Fisher Books; electronic rights by Medical Data Exchange.