Plasma and urinary catecholamines and their metabolites in chronic renal failure.
The effect of chronic renal failure (CRF) on the plasma concentration and urinary excretion of catecholamines and their metabolites was studied in 14 patients with varying degrees of chronic renal failure who had creatinine clearances of 19 to 77 mL/min. The results were compared with those obtained in a group of age-matched normal controls. Plasma catecholamine concentrations were significantly higher in the CRF patients compared with age-matched normal controls (456.9 +/- 303.1 v 278.5 +/- 81.1 pg/mL). The urinary metanephrine (0.6 +/- 0.6 mg/g creatinine) and vanillylmandelic acid (VMA) (6.6 +/- 4.2 mg/g creatinine) were within the normal range. No significant correlations were found between creatinine clearance and urinary metanephrine and VMA excretion or with the plasma catecholamine concentrations. Our observations indicate that, despite the decrease in creatinine clearance, urinary VMA and metanephrine determinations are valid screening tests for pheochromocytoma in patients with compromised renal function. Plasma catecholamine concentrations, however, show moderate elevation with decreasing renal function.