Urine Metanephrines

Urine metanephrines are a group of chemical compounds that can be detected in a urine sample. They are breakdown products of catecholamines, which are hormones released by the adrenal glands in response to stress. The main urine metanephrines of interest are metanephrine and normetanephrine. Measuring these compounds in urine is a valuable diagnostic tool for assessing adrenal function and detecting certain medical conditions, especially those related to the adrenal medulla, such as pheochromocytoma.

Urine metanephrines are measured to evaluate adrenal gland function and to diagnose or rule out conditions like pheochromocytoma. Pheochromocytoma is a rare tumor that can cause excessive release of catecholamines, leading to high blood pressure, rapid heart rate, and other symptoms. Elevated levels of metanephrines in the urine may indicate the presence of this tumor. Additionally, urine metanephrine testing can help monitor the effectiveness of treatment for pheochromocytoma.

The test involves collecting a urine sample over a 24-hour period. The patient typically begins by discarding the first morning void and then collecting all urine for the next 24 hours. The urine is stored in a special container to prevent breakdown of metanephrines. After collection, the sample is sent to a laboratory for analysis. It's crucial to follow the specific instructions provided by the healthcare provider to ensure accurate results.

Elevated urine metanephrine levels may suggest the presence of a pheochromocytoma or other conditions that lead to excessive catecholamine production. Further diagnostic tests, such as imaging studies and blood tests, may be necessary to confirm the diagnosis and locate the tumor. Elevated levels can also occur due to certain medications and dietary factors, so it's important to consider these aspects during the evaluation.