Different values of urinary fractionated metanephrines after unilateral adrenalectomy for pheochromocytoma according to time intervals after surgery

Background After adrenalectomy, urinary fractionated metanephrine concentrations are expected to be reduced. However, there are few studies suggesting cut-offs for adrenalectomy patients. Methods Urinary metanephrine and normetanephrine concentrations in adrenalectomy patients and two controls were compared and hormonal concentrations were evaluated via time intervals after surgery. Results The median urinary metanephrine level after unilateral adrenalectomy was lower than that of the non-pheochromocytoma controls but comparable to healthy controls. Urinary normetanephrine concentrations did not differ between adrenalectomy patients and non-pheochromocytoma controls, although both group had levels higher than those of healthy controls. The median urinary normetanephrine level in the immediate postoperative period was higher than in the later period. Conclusions Urinary metanephrine concentrations were lower after adrenalectomy, but urinary normetanephrine concentrations were not changed compared with the non-pheochromocytoma controls. However, urinary normetanephrine concentrations in the patient group were higher than levels in the heathy controls.