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Context Impaired glucose homeostasis is a common finding in pheochromocytoma (PHEO), especially with adrenergic phenotype. The possible contribution of incretin dysfunction to dysglycemia in PHEO patients has not been studied. Objective To compare changes in pancreatic endocrine function and gut hormones’ production during a liquid meal test before and 1 year after adrenalectomy. Methods In a prospective study, we included 18 patients with PHEO (13 females) with adrenergic biochemical phenotype. A liquid meal test with predefined isocaloric enteral nutrition was performed to evaluate dynamic changes in pancreatic hormones and incretins. Results During the meal test, insulin levels were significantly lower before adrenalectomy only in the early phase of insulin secretion, but changes in area under the curve (AUC) did not reach statistical significance (AUC = 0.07). Plasma glucagon (AUC Conclusions Our study shows suppression of pancreatic α and β cell function and impaired GLP-1 secretion during a dynamic meal test in patients with PHEO, which is improved after its surgical treatment. These data demonstrate a novel and potentially significant interconnection between excessive catecholamine production and the secretion of glucoregulatory hormones.

Context Impaired diurnal blood pressure (BP) variability is related to higher cardiovascular risk. Objective To assess diurnal variability of BP and its relation to target organ damage (TOD) and catecholamine phenotype in a consecutive sample of pheochromocytoma/paraganglioma (PPGL). Design We included 179 patients with PPGL All patients underwent 24 hours of ambulatory BP monitoring to determine dipping status. Differences in plasma metanephrine or urine adrenaline were used to distinguish catecholamine biochemical phenotype. To evaluate TOD, renal functions, presence of left ventricle hypertrophy (LVH), and the subgroup (n = 111) carotid-femoral pulse wave velocity (PWV) were assessed. Structural equation modeling was used to find the relationship among nocturnal dipping, catecholamine phenotype, and TOD parameters. Results According to the nocturnal dipping, patients were divided into the three groups: dippers (28%), nondippers (40%), and reverse dippers (32%). Reverse dippers were older (P < 0.05), with a higher proportion of noradrenergic (NA) phenotype (P < 0.05), a higher prevalence of diabetes mellitus (P < 0.05), and sustained arterial hypertension (P < 0.01) and its duration (P < 0.05), as opposed to the other groups. All parameters of TOD were more pronounced only in reverse dippers compared with nondippers and dippers. The presence of NA phenotype (=absence of adrenaline production) was associated with reverse dipping and TOD (LVH and PWV). Conclusions Patients with reverse dipping had more substantial TOD compared with other groups. The NA phenotype plays an important role, not only in impaired diurnal BP variability but also independently from dipping status in more pronounced TOD of heart and vessels.

Context Catecholamines may contribute to the accumulation of collagen fibers and extracellular matrix in the arterial and myocardial wall due to various mechanisms. Reversibility of this process has not been studied on both structures simultaneously. Objective To clarify the long-term effect of excess normalization of catecholamines on carotid and myocardial wall changes in patients with pheochromocytoma or functional paraganglioma (PHEO) after tumor removal. Design, Settings, and Patients Carotid intima-media thickness (IMT) and the left ventricular (LV) mass index were studied in 50 patients with PHEO before tumor removal and 5 years after tumor removal, and in 50 blood pressure- and age-matched essential hypertensive patients before follow-up and after 5 years of follow-up. Main Outcome Measures Common carotid artery (CCA)-IMT and LV mass indexed to lean body mass (LBM). Results Elimination of catecholamine excess in the PHEO group resulted in a significant decrease in CCA-IMT and LV mass index from 0.86 ± 0.17 to 0.83 ± 0.18 mm (P < 0.05) and from 3.2 ± 0.9 to 2.9 ± 0.9 g/LBM (P < 0.001), respectively. In contrast, CCA-IMT and LV mass index increased significantly from 0.78 ± 0.14 to 0.81 ± 0.15 mm (P < 0.05) and from 3.1 ± 0.7 to 3.2 ± 0.6 g/LBM (P < 0.05), respectively, in patients with essential hypertension. Conclusion In patients with PHEO, carotid IMT and LV mass index can significantly regress after tumor removal, in contrast to the impairment of these parameters in essential hypertensive patients during the same long-term period.