Objective: To evaluate the effect of long-term catecholamine overproduction in subjects with pheochromocytoma on arterial stiffness measured non-invasively by carotid-femoral pulse wave velocity (PWV) and central augmentation index (AI).

Design: Twenty two subjects with pheochromocytoma (PHEO), 34 subjects with essential hypertension (EH) and 40 healthy normotensive controls (C) were investigated using an applanation tonometer (Sphygmocor). Twelve patients with pheochromocytoma were studied after tumor removal.

Results: The gender, age, body mass index and lipid profiles were comparable among all the groups. Fasting plasma glucose levels in PHEO were higher in comparison to the other groups (6.1 ± 1.7 vs.EH 4.9 ± 1.1 vs.C 4.8 ± 0.8mmol/l;p<0.001 for all comparisons). Brachial blood pressure values in PHEO were lower in comparison to EH (135 ± 24/77 ± 12 vs. 153 ± 6/90 ± 11mmHg;p<0.001/0.001) and higher in comparison to C (135 ± 24/77 ± 12 vs.121 ± 11/72 ± 9mmHg;p<0.001/n.s.). The pulse wave velocity in pheochromocytoma did not differ from EH (7.1 ± 1.3 vs. 7.3 ± 1.5m.s⁻²,ns.) and was significantly higher than in controls (7.1 ± 1.3 vs. 5.9 ± 0.7m.s⁻²;p<0.001). No differences were found in AI among all groups. In multiple regression the only significant variables independently associated with PWV in pheochromocytoma were 24h urine norepinephrine excretion (β=0.566,p< 0.001) and fasting plasma glucose levels (β=0.346,p=0.015). Successful tumor removal led to a significant decrease in PWV (6.9 ± 0.8 vs. 5.5 ± 0.7m.s^−2;p<0.001).

Conclusion: Catecholamine excess in pheochromocytoma is accompanied by an increase in pulse wave velocity, which is reversed by the successful tumor removal. Pulse wave velocity in subjects with pheochromocytoma is positively associated with 24h urine norepinephrine levels and fasting plasma glucose levels.