Endocrine Abstracts

Many symptoms of phaeochromocytomas and paragangliomas (PPGL) are due to the effects of excess catecholamines. Catecholamines exert their effect on alpha- and beta-adrenergic receptors. Before patients undergo curative surgery, guidelines recommend medical management is commenced to provide cardiovascular stability. This blockade allows restoration of normotension and normal circulating volume (reducing the risks of an intraoperative hypertensive crisis and postoperative hypotension respectively). The value of preoperative medical therapy with alpha-blockade has recently been disputed, with suggestions that an experienced team can prevent much of the intra-operative haemodynamic instability. This is undoubtedly the case and remains of the utmost importance. However this suggestion assumes rapid access to operating lists, and precludes any benefits that patients may derive from blocking the effects of ongoing catecholamine secretion while awaiting surgery. Bioimpedance is a non-invasive measure of body composition parameters. Bioimpedance analysis and measurements of serum inflammatory and immune markers were studied to explore potential additional physiological benefits of alpha-blockade therapy to PPGL patients pre-operatively, compared to matched hypertensive control patients. At baseline measurements for the PPGL cohort were suggestive of a more catabolic state compared to the primary hypertensive control patients. PPGL patients had a lower weight, lower BMI, and reduced body fat, muscle mass and BMR compared to hypertensive controls. Treatment with alpha-blockade led to a significant improvement in all of the body composition parameters. Patients with a secretory PPGL had higher levels of white blood cells, platelets, ferritin, ALT, HbA1c, Troponin T, platelet-to-lymphocyte score and systemic index score at diagnosis. These all significantly decreased pre-operatively in the presence of alpha-blockade. There were no significant changes in any of the inflammatory or immune markers in the hypertensive controls despite a similar improvement in BP. These data demonstrate the potential to reverse the catabolic and inflammatory effects of catecholamine excess with pre-operative alpha-blockade therapy.