SUN-364 The Effects of Catecholamine Excess on Glucose Control: A Planned Approach to Insulin Management After Pheochromocytoma Removal
Year: 2024
Type: article
Study design: Case Report
Abstract: M. Koleti: None. M. Ahmad: None. L. Belalcazar: None. Introduction: The life-threatening cardiovascular complications of pheochromocytoma are well known, but the effects of catecholamine secretion on glucose homeostasis and their impact on the care of the patient with pheochromocytoma are underrecognized. We present a patient with long-standing diabetes and hypertension and describe how removal of a pheochromocytoma resulted in major changes in insulin therapy. Clinical Case: A 56-year-old woman with an 18+ year history of hypertension presented with angina, blurred vision and severe headache despite treatment with 3 anti-hypertensive agents. Blood pressure was 221/141 mmHg, heart rate 96/min; body mass index 36.2 kg/m2. Workup for resistant hypertension showed elevated plasma metanephrines (normetanephrine 6.52 nmol/L (0-0.89 nmol/L), metanephrine 2.61 nmol/L(0-0.49 nmol/L)). CT scan revealed a 3.9 cm right adrenal mass compatible with pheochromocytoma. Patient was started on terazosin in preparation for adrenalectomy. She was readmitted a month later with a recurrent hypertensive emergency due to treatment non-adherence. Patient restarted terazosin under close medical supervision for 15 days prior to surgery; low-dose metoprolol was added for heart rate control and salt loading to avoid orthostasis. Patient also had a history of type 2 diabetes for 12 years with good control (HbA1c 5.9-6.5%). When her diabetes was re-evaluated in the setting of pheochromocytoma, her glycemic control was poor despite her usual daily dose of 30 units of insulin (HbA1c 10.4%). In the hospital, prior to adrenalectomy, the patient was requiring 70 units of insulin (∼0.8 u/kg) per day with glucose levels in the 130-200 mg/dL range. After surgery, intravenous dextrose fluids were administered until she resumed full meals; her scheduled insulin was decreased by half and insulin dose adjustments prescribed for bedside management based on glucose monitoring. Insulin requirements continued to decrease daily, and at the time of discharge 8 days after surgery, the patient was no longer on insulin. Her blood pressure control improved off terazosin but still required low-dose medications. Repeat metanephrine levels on day 6 after surgery had normalized (normetanephrine 0.79 nmol/L (0-0.89 nmol/L), metanephrine 0.14 nmol/L (0-0.49 nmol/L); pathology confirmed the diagnosis of pheochromocytoma. Clinical Lessons: The counter-regulatory effects of catecholamines in patients with pheochromocytoma may lead to dysglycemia and, in diabetes, result in an increase in insulin needs. After tumor resection, it is necessary to remain vigilant and actively adjust insulin therapy to avoid hypoglycemia. Patients on insulin therapy may demonstrate a marked reduction in insulin requirements and progress to diabetes remission after tumor removal. As seen in our patient, improvement in glycemic control may occur in the immediate postoperative period. Sunday, June 2, 2024
Source: Journal of the Endocrine Society
Institution: The University of Texas Medical Branch at Galveston
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,418
OpenAlex ID: W4409965727