Bone Resorption Is Increased in Pheochromocytoma Patients and Normalizes following Adrenalectomy

Context: The sympathetic nervous system (SNS) controls bone turnover in rodents, but it is uncer-tain whether a similar role for the SNS exists in humans. Pheochromocytomas are catecholamine-producing neuroendocrine tumors. Because catecholamines are the neurotransmitters of the SNS, we hypothesized that pheochromocytoma patients have increased bone turnover. Objective: Our objective was to compare bone turnover in pheochromocytoma patients and controls. Design and Setting: This retrospective case-control study was performed at the Endocrine Depart-ment of the Academic Medical Center of the University of Amsterdam in The Netherlands from 2007 until 2011. Patients:All patientswere screened for pheochromocytoma. Cases (n21)were identifiedby 24-h urinary excretion of fractionated metanephrines above the institutional reference value and con-firmed by histology after adrenalectomy. All patients screened and diagnosed as not having pheo-chromocytoma served as controls (n 126). Main Outcome Measure: The difference in bone turnover markers C-terminal cross-linking telo-peptides of collagen type I (CTx) and procollagen type 1 N propeptide (P1NP) between cases and controls was the main outcome measure. Results: CTx concentrations were higher in cases [343 ng/liter; interquartile range (IQR), 295 ng/ liter] than in controls (232 ng/liter; IQR, 168 ng/liter; P 0.001) and decreased after adrenalectom