Vanylmandelic acid is a degradation product generally detectable by urinalysis. Before undergoing this test, however, it is good to follow important precautions to avoid obtaining incorrect results. What is Vanilmandelic acid
It is one of the most important degradation products, as well as the main catabolite of adrenaline and noradrenaline, two important catecholamines. Thanks to the action of monoamine oxidase, they first become metanephrine and normetanephrine and, later, Vanilmandelic acid or VMA – from the English vanillyl mandelic acid. In healthy subjects, Vanylmandelic Acid is present in the position of about 50% of all the degradation products of the catecholamines present. Because the vanilmandelic acid test is required
Unfortunately, in most cases, asking for this exam is never associated with something pleasant. Vanilmandelic acid, in fact, is used in the diagnosis of pheochromocytoma, a tumor typical of chromaffin cells, and therefore of the adrenal gland. In subjects affected by this pathology the values are generally high. The test is also useful for ruling out neuroblastoma in pediatric subjects with abdominal masses.
- What are chromaffin cells
These are neuroendocrine cells located in the medulla of the adrenal glands, just above the kidneys. But they can also be found in some ganglia of the sympathetic nervous system. Their main function is to secrete adrenaline, noradrenaline and enkephalin. Its particular name is due to the characteristic of being able to be detected through a treatment of chromium salts.
How to perform the urine test for Vanylmandelic Acid
The test is performed by collecting urine samples over a period of 24 hours. Once this sample has been collected, the laboratory will examine it following acidification of the urine with hydrochloric acid. Vanilmandelic acid and creatinine
The test could be requested together with that of creatinine, both in the case of detection of WMA or, also in the detection of homovanilic acid (HVA), useful for the diagnosis of pediatric neuroblastoma. In the latter case there is in any case a possibility of false positives of about 3.5% of cases. Preparation for the Vanilmandelic Acid exam
Preparation for the exam is very important and must be done very carefully. Incorrect diet and lifestyle could in fact distort the results. For this reason it is strictly required to follow a controlled diet from 72 hours prior to the first harvest.
- Deepening: what is pheochromocytoma
The negative side is that pheochromocytoma is a tumor; the positive one is that in most cases it is benign. It originates from chromaffin cells that reside in the neuroectoderm, an area of the sympathetic system. These cells migrate originating chromaffin tissues, of which one of the most important is that of the adrenal medulla, the place where catecholamines are synthesized.
The diet before the urinalysis
It is necessary to exclude cheeses, nuts, bananas, coffee, chocolate, tea (and all foods that contain xanthines), kiwis, bananas, food supplements, mate grass, exotic fruits such as Guarana and Avocado, foods containing citrates, vanilla, candied fruit, carbonated drinks.
Before the urinalysis for Vanilmandelic acid first follow a particular diet The lifestyle to follow Another
important precaution concerns the lifestyle. Not only sport – especially intense – and physical exertion are prohibited. But also stress of any kind and strong emotions. Drugs that may interact with the Vanylmandelic Acid test
Ask your doctor if you are taking any medications that affect Vanylmandelic Acid levels such as sympathomimetics. But also antidepressants, amphetamines and derivatives, acetylsalicylic acid, histamine, diuretics, nasal decongestants, Levodopa, Reserpina etc. Vanylmandelic acid: normal values
Adults: 1 – 11 mg / 24 hours – 1-7.1 mg of VMA / g of creatinine – 9.1-35.8 μmol / 24 h
Children: 0.10 – 0.18 mg / 24 hours for Kg of body weight
The values referred to the vanilmandelic acid / creatinine ratio are performed only on a urine sample instead of the 24 hour collection. Vanilmandelic acid and cancer
Fortunately, high levels of Vanylmandelic Acid are not always associated with cancer. As mentioned, sometimes there may be false positives due to taking certain types of medications or inappropriate lifestyles. Here are other reasons why the levels may be high:
- Intake of nerve foods in the previous days (coffee, tea, chocolate, cola, guarana …)
- Intake of fruits such as bananas, kiwis, avocados
- Medication intake (amphetamines, tetracyclines, diuretics, MAO inhibitors, clonidine, chlorpromazine, furosemide, glyceryltrinitrate, etc.)
If Vanilmandelic acid is low it is
a rather rare but possible fact. In principle, the motivation is attributable to the intake of drugs based on clofibrate used in subjects with high triglycerides and cholesterol. Scientific sources
[1] VMA – Vanillylmandelic Acid, urine
[2] Clin Biochem. 1987 Jun; 20 (3): 173-7. Determination of urinary homovanillic and vanillylmandelic acids from dried filter paper samples: assessment of potential methods for neuroblastoma screening. Tuchman M, Auray-Blais C, Ramnaraine ML, Neglia J, Krivit W, Lemieux B.
[3] Pediatr Blood Cancer. 2007 May; 48 (5): 504-9. Diagnostic and prognostic impact of urinary catecholamines in neuroblastoma patients. Strenger V, Kerbl R, Dornbusch HJ, Ladenstein R, Ambros PF, Ambros IM, Urban C.
[4] Clin Lab Sci. 1991 Jul-Aug;4(4):237-41. Simultaneous measurement of VMA and HVA in 24-hour urine samples. Harr R.
