Urine analysis is a very important and informative method for diagnosing various diseases. Sometimes there is a need for this study to determine the level of metanephrine. An increase in it in the patient's urine may indicate the development of dangerous pathological processes. What is metanephrine and what does the deviation of its level from the norm mean, we will consider in the article.
Definition
Metanephrine and normetanephrine are intermediate breakdown products of catecholamine hormones - adrenaline and norepinephrine, which are of great importance in adapting the body to stressful situations. Having fulfilled their functions, these hormones naturally break down and are excreted in the urine within a day. For this reason, a small amount of metanephrine in the urine, as well as its slight increase under stress, is normal. A significant or prolonged increase in this indicator may indicate the development of neuroendocrinetumors in which stress hormones are produced in an increased volume, as a result of which an increase in the volume of their decay products in the urine is observed. Additional diagnostic measures are needed.
Norms
Below is a table of normal values.
| Age | Metanephrine, mcg/day | Normetanephrine, mcg/day |
| 0 to 3 months | 5, 9-37 | 46-156 |
| 3 to 6 months | 6, 1-42 | 31-111 |
| 6 to 9 months | 12-41 | 42-109 |
| 9 to 12 months | 8, 5-101 | 23-103 |
| 1 to 2 years old | 6, 7-52 | 32-118 |
| 2 to 6 years old | 11-100 | 50-111 |
| 6 to 10 years old | 54-136 | 47-175 |
| 10 to 16 years old | 39-243 | 52-290 |
| Adults | 0-320 | 0-390 |
Norms do not depend on gender, but differ significantly by age.
Normal values may vary depending on the laboratory. In this regard, a second analysis is recommended to be carried out in the same clinic as the previous time.
When to get tested
There are a number of signs, upon detection of which it is necessary to contact a medical institution as soon as possible and pass an analysis to detect metanephrines and normetanephrines in the urine. For these symptomsinclude:
- Prolonged high blood pressure, which is difficult to normalize.
- Irregular heart rhythms.
- Sustained increase in body temperature (may be slight).
- Dry mouth.
- Nausea.
- Dizziness, sleep disturbance, weakness.
- Weight loss without loss of appetite.
- Excessive sweating even at rest.
- Headaches.
- Panic attacks.
- Pre-fainting or fainting.
- Nervousness, excitability, mood swings.
- Jumps in glucose levels (regardless of the presence of diabetes).
Urine tests for metanephrine and normetanephrine are also indicated for suspected neuroendocrine malignancies.
Referral for analysis in most cases is issued by a therapist, oncologist, surgeon or endocrinologist.
Preparation
When analyzing daily urine for metanephrine, careful preparation is very important, since these indicators are very sensitive to the influence of external circumstances. Consider the basic rules recommended for implementation before collecting:
- First of all, a few days before the analysis, you should stop taking certain categories of medicines. These include some antibiotics, tranquilizers, blockers, vasoconstrictors, and others.
- No smoking for 4 hours.
- For 2 days before the analysis, exclude the use of coffee, chocolate, alcoholic beverages, eggs, products,containing vanillin, avocado, bananas, tomatoes and others.
- Avoid physical activity.
- Exclude nervous tension.
Rules for passing the analysis
To detect metanephrine, daily urine is used. This will require a large sterile container, which will be collected throughout the day. Before each urination, hygiene procedures must be carried out.
The first morning urine must be poured out, all subsequent urine must be collected in one container. After each filling, the container is placed in a cold place. On the morning of the next day, about 100 ml should be separated from the total volume of collected urine. After that, you need to deliver the sample to the laboratory as soon as possible (no later than four hours).
Increasing values
Elevated values of metanephrines in daily urine may indicate the presence of malignant tumors or be the result of improper sampling of the analysis. The most common reasons for a raise are:
- Stress, especially prolonged.
- Great physical activity before analysis.
- Drinking alcohol or smoking before urine sampling.
- Medications that may interfere with results.
But sometimes an increase in values indicates the development of dangerous diseases, which include:
- Tumors of the adrenal glands. This produces an increased amount of catecholamines. It should be noted that the analysiscan indicate the size of the tumor or its complications. Additional testing needed.
- Benign or malignant neurotumors (eg, paragangliomas, neuroblastomas, and ganglioneuromas).
- Hepatitis or cirrhosis of the liver.
- Increased metanephrines and normetanephrines in daily urine can cause heart and vascular disease (myocardial infarction, angina pectoris, heart failure).
- Pathological conditions occurring in the hypothalamus, which provoke failures in the sympathoadrenal system.
- Acute ulcers of the duodenum or stomach.
- Hypertension, manifested in an acute form.
There are situations in which a false positive result is diagnosed. It is necessary to consult a doctor and undergo additional tests to confirm or exclude dangerous pathologies. For example, an analysis may be prescribed for the level of catecholamines themselves in the urine, as well as the end products of their metabolism.
A constant increase in normetanephrine indicates the development of pathological conditions that have arisen in the hypothalamus or in internal organs.
In the event that an increase in metanephrine and normetanephrine is detected after undergoing a course of treatment for tumor processes occurring in the body, this may be evidence of poor-quality treatment or the development of a relapse of the disease. Seek medical attention as soon as possible.
Reduced values
Decreased values of metanephrine in the urine may indicate diseases such as:
- Leukemia.
- Chronic and acute inflammatory processes occurring in the body.
- Addison's disease.
- Connective tissue diseases.
It is worth noting that a decrease in performance is quite rare and may be the result of improper urine sampling or the use of a non-sterile container.
Additional diagnostics
When detecting deviations from the normal values of the level of metanephrine and normetanephrine, to clarify the diagnosis, the doctor prescribes a set of additional diagnostic measures, which include the following studies:
- Complete blood count.
- ECG.
- EEG.
- Biochemical blood test.
- Ultrasound examination of the adrenal glands, abdominal cavity and other organs.
- Endoscopy.
- MRI of the adrenal glands to determine their condition.
- Computed tomography and others.
Also be sure to repeat the urine test for changes in the level of metanephrine and normetanephrine.
Conclusion
Every person needs to monitor their he alth as carefully as possible, and at the first suspicious signs, you should contact a doctor as soon as possible, who will determine a number of necessary diagnostic measures. Timely diagnosis will identify dangerous diseases at an early stage, which will help prescribe effective therapy, because some pathological conditions that occur in the body, without timely treatment, can be a threat to human life and he alth.
Urine analysis for the level of metanephrines is recommended to be included in the systematic examination mode, since this indicator allows to identify many life-threatening diseases. But you need to remember the rules for preparing for the analysis and its implementation, because if you collect urine incorrectly, you can get a false result.
