Will the resection of pheochromocytoma improve preoperative diabetes mellitus?

Main mechanisms and clinical implications of alterations in energy expenditure state among patients with pheochromocytoma and paraganglioma: A review

Pheochromocytoma and paraganglioma (PPGL) are rare neuroendocrine tumors with diverse clinical presentations. Alterations in energy expenditure state are commonly observed in patients with PPGL. However, the reported prevalence of hypermetabolism varies significantly and the underlying mechanisms and implications of this presentation have not been well elucidated. This review discusses and analyzes the factors that contribute to energy consumption. Elevated catecholamine levels in patients can significantly affect substance and energy metabolism. Additionally, changes in the activation of brown adipose tissue (BAT), inflammation, and the inherent energy demands of the tumor can contribute to increased resting energy expenditure (REE) and other energy metabolism indicators. The PPGL biomarker, chromogranin A (CgA), and its fragments also influence energy metabolism. Chronic hypermetabolic states may be detrimental to these patients, with surgical tumor removal remaining the primary therapeutic intervention. The high energy expenditure of PPGL has not received the attention it deserves, and an accurate assessment of energy metabolism is the cornerstone for an adequate understanding and treatment of the disease.

Secondary diabetes mellitus in pheochromocytomas and paragangliomas

Secondary diabetes mellitus (DM) in secretory pheochromocytomas and paragangliomas (PPGLs) is encountered in up to 50% of cases, with its presentation ranging from mild, insulin resistant forms to profound insulin deficiency states, such as diabetic ketoacidosis and hyperglycemic hyperosmolar state. PPGLs represent hypermetabolic states, in which adrenaline and noradrenaline induce insulin resistance in target tissues characterized by aerobic glycolysis, excessive lipolysis, altered adipokine expression, subclinical inflammation, as well as enhanced gluconeogenesis and glucogenolysis. These effects are mediated both directly, upon adrenergic receptor stimulation, and indirectly, via increased glucagon secretion. Impaired insulin secretion is the principal pathogenetic mechanism of secondary DM in this setting; yet, this is relevant for tumors with adrenergic phenotype, arising from direct inhibitory actions in beta pancreatic cells and incretin effect impairment. In contrast, insulin secretion might be enhanced in tumors with noradrenergic phenotype. This dimorphic effect might correspond to two distinct glycemic phenotypes, with predominant insulin resistance and insulin deficiency respectively. Secondary DM improves substantially post-surgery, with up to 80% remission rate. The fact that surgical treatment of PPGLs restores insulin sensitivity and secretion at greater extent compared to alpha and beta blockade, implies the existence of further, non-adrenergic mechanisms, possibly involving other hormonal co-secretion by these tumors. DM management in PPGLs is scarcely studied. The efficacy and safety of newer anti-diabetic medications, such as glucagon-like peptide 1 receptor agonists and sodium glucose cotransporter 2 inhibitors (SGLT2is), as well as potential disease-modifying roles of metformin and SGLT2is warrant further investigation in future studies.

Factors contributing to development and resolution of dysglycemia in patients with pheochromocytomas and catecholamine-secreting paragangliomas

BACKGROUND

Pheochromocytomas and paragangliomas (PPGLs) are a group of rare neuroendocrine tumors. Dysglycemia has been observed in patients with PPGLs in some small case series. However, there is limited information available on the factors associated with development and resolution of dysglycemia in these patients.

PATIENTS AND METHODS

The clinical data of consecutive patients admitted to our hospital with PPGLs between January 2018 and June 2020 were retrospectively analyzed. Clinical characteristics were compared between patients with and without dysglycemia. Logistic regression analysis was used to identify risk factors and receiver-operating characteristic (ROC) curve analysis was used to evaluate the diagnostic performance of the variables.

RESULTS

Among 163 patients, 58.9% had preoperative dysglycemia. Patients with dysglycemia were significantly older at diagnosis (p = 0.01) and were significantly more likely to have hypertension (p = 0.007). White blood cell counts (p = 0.016), 24-hour urinary epinephrine (24hU-E) levels (p < 0.001) and 24-hour urinary norepinethrine levels (p = 0.008) were significantly higher in patients with dysglycemia. Regression analysis showed that age (odds ratio [OR] 1.028, 95% confidence interval [CI] 1.001-1.055; p = 0.041), hypertension (OR 2.164, 95% CI 1.014-4.619; p = 0.046) and the 24hU-E concentration (OR 1.010, 95% CI, 1.001-1.019; p = 0.025) were positively associated with preoperative dysglycemia. Taking age, hypertension, and 24hU-E into account in the same model, the area under the ROC curve for prediction of preoperative dysglycemia was 0.703. The proportion of patients with dysglycemia decreased significantly after surgery (p < 0.001) and patients with preoperative dyssglycemia that resolved after surgery tended to have a larger preoperative tumor diameter (p = 0.018).

CONCLUSION

Age, hypertension, and the 24hU-E concentration are risk factors for preoperative dysglycemia. Removal of PPGLs can improve dysglycemia in most patients, and postoperative remission of dysglycemia is associated with the preoperative tumor diameter. These results are important for risk assessment and for selecting optimal therapies in patients with dysglycemia in PPGLs.KEY MESSAGESThere have been insufficient data to identify factors associated with development and resolution of dysglycemia in patients with PPGLs.Our results show that approximately half of the patients with PPGLs develop dysglycemia; age, hypertension, and the 24hU-E concentration are risk factors for preoperative dysglycemia.Removal of the PPGLs improves dysglycemia in a majority of patients, and a large preoperative tumor diameter is associated with remission of dysglycemia after surgery.

Practical therapeutic approach in the management of diabetes mellitus secondary to Cushing's syndrome, acromegaly and neuroendocrine tumours

Cushing's syndrome, acromegaly and neuroendocrine disorders are characterized by an excess of counterregulatory hormones, able to induce insulin resistance and glucose metabolism disorders at variable degrees and requiring immediate treatment, until patients are ready to undergo surgery. This review focuses on the management of diabetes mellitus in endocrine disorders related to an excess of counterregulatory hormones. Currently, the landscape of approved agents for treatment of diabetes is dynamic and is mainly patient-centred and not glycaemia-centred. In addition, personalized medicine is more and more required to provide a precise approach to the patient's disease. For this reason, we aimed to define a practical therapeutic algorithm for management of diabetes mellitus in patients with glucagonoma, pheochromocytoma, Cushing's syndrome and acromegaly, based on our practical experience and on the physiopathology of the specific endocrine disease taken into account. This document is addressed to all specialists who approach patients with diabetes mellitus secondary to endocrine disorders characterized by an excess of counterregulatory hormones, in order to take better care of these patients. Care and control of diabetes mellitus should be one of the primary goals in patients with an excess of counterregulatory hormones requiring immediate and aggressive treatment.

A Double-Headed Physiologic Monster: A Case Report and Literature Review

Adrenal incidentaloma (AI) is rare and found in approximately 2-4% of abdominal computed tomography scans. Up to 10% of patients with AI have autonomous secretion of adrenal hormones. If not quickly diagnosed and adequately treated, the outcome may be devastating to the patient. On very rare occasions, a pheochromocytoma may, in addition to the production of catecholamine, produce adrenocorticotropic hormone causing Cushing disease. We present a case of a patient with pheochromocytoma and Cushing syndrome.

Pathophysiology and Management of Glycemic Alterations before and after Surgery for Pheochromocytoma and Paraganglioma

Glycemic alterations are frequent in patients with pheochromocytoma and paraganglioma (PPGL), but the real incidence of secondary diabetes mellitus (DM) is uncertain, because prospective multicenter studies on this topic are lacking in the literature. The main pathophysiological mechanisms of glucose homeostasis alterations in PPGL, related to catecholamine hypersecretion, are impaired insulin and glucagon-like peptide type 1 (GLP-1) secretion and increased insulin resistance. Moreover, it has been reported that different pathways leading to glucose intolerance may be related to the secretory phenotype of the chromaffin tumor. Predictive factors for the development of glucose intolerance in PPGL patients are a higher age at diagnosis, the need for a higher number of anti-hypertensive drugs, and the presence of secreting neoplasms. Tumor resection is strongly related to the resolution of DM in PPGL patients, with a significant improvement of glycemic control in most cases. We can hypothesize a different personalized therapeutic approach based on the secretory phenotype. The adrenergic phenotype is more closely related to reduced insulin secretion, so insulin therapy may be required. On the other hand, the noradrenergic phenotype mainly acts by increasing insulin resistance and, therefore, insulin-sensitizing antidiabetic agents can find a greater application. Regarding GLP-1 receptor agonists, the data suggest a possible promising therapeutic effect, based on the assumption that GLP-1 secretion is impaired in patients with PPGL. The principal predictors of remission of glycemic alterations after surgery for PPGL are a lower preoperative body mass index (BMI), a larger tumor, higher preoperative catecholamine levels, and a shorter duration of the disease (under three years). Otherwise, after resection of PPGL, hypoglycemia can occur as the result of an excessive rebound of preoperative hyperinsulinemia. It is a rare, but potentially severe complication reported in a lot of case reports and a few small retrospective studies. Higher 24-h urinary metanephrine levels, longer operative times and larger tumors are predictive factors for hypoglycemia in this setting. In conclusion, alterations of carbohydrate metabolism are clinically relevant manifestations of PPGL before and after surgery, but there is the need to conduct multicenter prospective studies to obtain an adequate sample size, and to allow the creation of shared strategies for the clinical management of these potentially severe manifestations of PPGL.

Glycemic disorders in patients with pheochromocytomas and sympathetic paragangliomas

The objective of our study was to determine the prevalence of glycemic disorders (diabetes mellitus and prediabetes) in patients with pheochromocytomas and sympathetic paragangliomas (PPGLs) and identify risk factors for their development and the likelihood of their resolution after surgery. A multicentric retrospective study of patients with PPGLs submitted to surgery between 2000 and 2021 in 17 Spanish hospitals was performed. Diabetes-specific data were collected at diagnosis, in the immediate- and long-term postsurgical follow-up. A total of 229 patients with PPGLs were included (218 with pheochromocytomas and 11 with sympathetic paragangliomas). Before surgery, glycemic disorders were diagnosed in 35.4% of the patients (n = 81): 54 with diabetes and 27 with prediabetes. The variables independently associated with a higher risk of glycemic disorders were sporadic PPGL (odds ratio (OR) = 3.26 (1.14-9.36)) and hypertension (OR = 3.14 (1.09-9.01)). A significant decrease in fasting plasma glucose and HbA1c levels was observed after surgery, in the short-term and long-term follow-up (P < 0.001). After a median follow-up of 48.5 months (range 3.3-168.9), after surgery, 52% of diabetic and 68% of prediabetic patients experienced a complete resolution. Lower body mass index (BMI) (P = 0.001), lower glucose levels (P = 0.047) and shorter duration of diabetes prior to surgery (P = 0.021) were associated with a higher probability of diabetes resolution. In conclusion, glycemic disorders in patients with PPGLs are present in more than a third of them at diagnosis. Sporadic PPGLs and hypertension are risk factors for their development. More than 50% of cases experience a complete resolution of the glycemic disorder after resection of the PPGLs.

Pheochromocytoma and glucoregulation disorders

Introduction:

Pheochromocytomas are catecholamine-producing tumors presenting with various clinical symptoms and a serious potentially lethal cardiovascular complications due to the potent effects of secreted catecholamines. Glucoregulation disorders could also occur leading to impaired glucose tolerance and diabetes mellitus. The aim of our study was to determine the effects of adrenalectomy on patient recovery with regard to their glycemic status.

Materials and Methods:

Case notes of all patients who underwent adrenalectomy surgery for pheochromocytoma from 2009 to 2018, followed up in the Department of Diabetology, Endocrinology, and Nutrition at University Hospital Center Hassan II of Fez, were retrieved, and data were collected from them to identify those with preoperative diagnosis of glucoregulation disorder and to verify if adrenalectomy can reverse or improve glycemic abnormality.

Results:

Overall, 23 patients underwent surgery for pheochromocytoma, 26% of cases had diabetes mellitus, whereas 34.78% had glucose intolerance. One year after surgery, diabetes and glucose intolerance were cured in 57.14% of cases. We noticed also that patients with large and symptomatic tumors were more likely to develop preoperative diabetes; it was also more likely to persist in patients who had an elevated body mass index (BMI).

Conclusions:

In our data, diabetes and glucose intolerance were found concurrently with pheochromocytoma in 60.78% of patients. Thus, it is important for clinicians to screen for glycemic disorder when pheochromocytoma is diagnosed, especially in patients with other risk factors for developing type 2 diabetes such as elevated BMI. Removal of these tumors can reduce insulin secretion and severe peripheral insulin resistance making early diagnosis important.