Reference Interval:
| | | Components
| Reference Interval
| | Metanephrine
| 30-350 µg/d
| | Normetanephrine
| 50-650 µg/d
|
| The metanephrines-to-creatinine ratios will be reported when the patient is under 18 years, or the urine collection is random or other than 24 hours, or the urine volume is less than 400 mL/24 hours.
| | Test Number
| Components
| Reference Interval
| | | Metanephrine | | | | Age
| Reference Interval
| 0-3 months
4-6 months
7-11 months
1 year
2-5 years
6-17 years
18 years and older
| 0-700 µg/g crt
0-650 µg/g crt
0-650 µg/g crt
0-530 µg/g crt
0-500 µg/g crt
0-320 µg/g crt
0-300 µg/g crt
|
| | | Normetanephrine | | | | Age
| Reference Interval
| 0-3 months
4-6 months
7-11 months
1 year
2-5 years
6-17 years
18 years and older
| 0-3400 µg/g crt
0-2200 µg/g crt
0-1100 µg/g crt
0-1300 µg/g crt
0-610 µg/g crt
0-450 µg/g crt
0-400 µg/g crt
|
| | | Creatinine (24-hour)
| | Male
| Female
| 3-8 years: 140-700 mg/d
9-12 years: 300-1300 mg/d
13-17 years: 500-2300 mg/d
18-50 years: 1000-2500 mg/d
51-80 years: 800-2100 mg/d
81 years and older: 600-2000 mg/d
| 3-8 years: 140-700 mg/d
9-12 years: 300-1300 mg/d
13-17 years: 400-1600 mg/d
18-50 years: 700-1600 mg/d
51-80 years: 500-1400 mg/d
81 years and older: 400-1300 mg/d
|
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|
| Interpretive Data: |
Ratios to creatinine may be useful for evaluation of patients younger than 18 years of age, when the urine collection is random or other than 24 hours, or the urine volume is less than 400 mL/24 hours.
Mass per day (mg or µg) calculations are not reported when the urine collection is random or other than 24 hours, or the urine volume is less than 400 mL/24 hours.
Smaller increases in normetanephrine and/or metanephrine concentrations (less than two times the upper reference limit) usually are the result of physiological stimuli, drugs, or improper specimen collection. Significant elevation of one or both metanephrines (3 or more times the upper reference limit) is associated with an increased probability of a neuroendocrine tumor.
|
| Note: |
Secreting neuroendocrine tumors typically are associated with metanephrine or normetanephrine concentrations several times higher than the upper reference intervals. Other reasons for elevated concentrations include intense physical activity, life-threatening illness, and drug interferences. Essential hypertension is often associated with slight elevations (metanephrine less than 700 µg/day and normetanephrine less than 900 µg/day). Other reasons for slight and moderate elevations include emotional and physical stress and improper specimen collection.
Medications which may physiologically interfere with metanephrines include amphetamines and amphetamine-like compounds, appetite suppressants, bromocriptine, buspirone, caffeine, carbidopa-levodopa (Sinemet), clonidine, dexamethasone, diuretics (in doses sufficient to deplete sodium), methyldopa (Aldomet), MAO inhibitors, nose drops, propafenone (Rythmol), tricyclic antidepressants, and vasodilators. The effects of some drugs on catecholamine metabolite results may not be predictable.
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| CPT Code(s): |
83835
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