Elevated Metanephrines

An increased concentration of metanephrine and/or normetanephrine, suggesting excessive sympathetic-adrenal activity or catecholamine-secreting tumors.

• Metanephrine

  • Plasma: <0.50 nmol/L or ≤57 pg/mL

  • Urine: 30-261 μg/24hr

• Normetanephrine

  • Plasma: <0.90 nmol/L or ≤148 pg/mL

  • Urine: 103-646 μg/24hr

Causes

• Catecholamine-secreting tumors

  • Pheochromocytoma

  • Paraganglioma

• Physiological stress states

  • Severe physical stress

  • Acute illness

  • Major surgery

  • Severe pain

  • Sleep apnea

  • Anxiety and panic states

• Medications

  • Antidepressants (especially TCA and SNRI)

  • β-blockers

  • Clonidine withdrawal

  • Alcohol withdrawal

  • Amphetamines

  • Cocaine

• Dietary factors: Tyramine-rich foods

  • Aged cheeses

  • Fermented foods

  • Cured meats