24-hour Urine Metanephrines

• Test Name: 24-Hour Urine Metanephrines Test
• Test Type: Urinary biochemical test
• Specimen Required: 24-hour urine collection
• Methodology: High-performance liquid chromatography (HPLC) or liquid chromatography-mass spectrometry (LC-MS)
• Purpose: Measures the levels of metanephrines (metanephrine and normetanephrine) in urine to evaluate adrenal gland function and detect conditions such as pheochromocytoma or paraganglioma.

• Diagnosis: Assists in diagnosing pheochromocytoma or paraganglioma by detecting elevated levels of metanephrines, which are metabolites of catecholamines (epinephrine and norepinephrine).
• Monitoring: Used to monitor patients with known pheochromocytoma or paraganglioma to assess treatment response or disease progression.
• Preoperative Assessment: Helps in the preoperative evaluation of patients undergoing surgery for adrenal tumors by confirming the diagnosis and assessing tumor activity.
• Evaluation of Symptoms: Helps in the investigation of symptoms consistent with catecholamine excess, such as hypertension, sweating, and palpitations.

• Components:
  • Collection of urine over a 24-hour period.
  • Analysis of urine samples to measure the concentration of metanephrine and normetanephrine.
  • Calibration with standard controls to ensure accuracy.
  • Report on the concentration of metanephrines in micrograms per 24 hours
     
• Procedure:
  • The patient collects all urine for a 24-hour period in a provided container.
  • The collected urine is processed and analyzed using HPLC or LC-MS.
  • Results are compared to reference ranges to determine if levels are elevated.

• Normal Findings: Metanephrine and normetanephrine levels are within the normal reference range, suggesting a lower likelihood of pheochromocytoma or paraganglioma.
• Elevated Levels: Higher levels of metanephrines indicate a potential pheochromocytoma or paraganglioma, and further diagnostic evaluation may be required.
• Clinical Correlation: Elevated levels should be correlated with clinical symptoms and other diagnostic tests, such as imaging studies, to confirm the diagnosis.
• False Positives/Negatives: Factors like medications, stress, or dietary intake can affect test results, so results should be interpreted in the clinical context.

• Qualitative and Quantitative: Provides quantitative measurements of metanephrine and normetanephrine levels in the urine.
• Interpretation: Results are interpreted based on concentration levels compared to established reference ranges.
• Report: A detailed report is provided, including measured levels of metanephrines and their clinical significance.
• Turnaround Time: Typically 1-2 weeks, depending on the laboratory's processing and analysis times.

Q. What is the 24-Hour Urine Metanephrines Test?
This test measures the levels of metanephrines (metanephrine and normetanephrine) in urine over a 24-hour period to help diagnose and monitor adrenal gland tumours such as pheochromocytoma
 

Q. Why is the 24-hour Urine Metanephrines Test ordered?
It is ordered to diagnose pheochromocytoma or paraganglioma, monitor disease progression, and evaluate symptoms associated with excess catecholamines
 

Q. How is the 24-hour Urine Metanephrines Test performed?
The patient collects all urine produced over a 24-hour period into a provided container. The urine is then analyzed in the laboratory for metanephrine and normetanephrine levels
 

Q. What do elevated levels of metanephrines indicate?
Elevated levels of metanephrines may indicate the presence of pheochromocytoma or paraganglioma, but further testing and clinical correlation are needed for a definitive diagnosis
 

Q. Can medications or foods affect the 24-hour Urine Metanephrines Test results?
Yes, certain medications, foods, and stress can affect metanephrine levels. Patients should inform their healthcare provider about any medications or dietary restrictions before the test
 

Q. How should I prepare for the 24-hour Urine Metanephrines Test?
Follow any specific instructions provided by your healthcare provider, which may include dietary restrictions and discontinuation of certain medications. Ensure complete urine collection over the 24-hour period
 

Q. How long does it take to get results from the 24-hour Urine Metanephrines Test?
Results are typically available within 1-2 weeks after the urine sample is processed and analyzed by the laboratory