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 MESSAGES: 1. There have been insufficient data to identify factors associated with development and resolution of dysglycemia in patients with PPGLs. 2. 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. 3. 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.