Prolonged and Nocturnal Hypoglycemia Following Resection of Pheochromocytoma and Paraganglioma: A Prospective Study Using Intermittent‐Scanning Continuous Glucose Monitoring
Yuki Nakamura, Sho Uehara, Shunya Matsumoto, Masaki Kobayashi, Yudai Ishikawa, Shohei Fukuda, Hiroshi Fukushima, Yuma Waseda, Yosuke Yasuda, Hajime Tanaka, Soichiro Yoshida, Masanori Murakami, Tetsuya Yamada, Yasuhisa FujiiABSTRACT
Objectives
To characterize the temporal dynamics and persistence of hypoglycemia following the resection of pheochromocytoma and paraganglioma using intermittent‐scanning continuous glucose monitoring.
Methods
Twenty‐two patients who underwent resection of pheochromocytoma ( n = 20) or paraganglioma ( n = 2) were prospectively enrolled. Perioperative glucose levels were tracked using intermittent‐scanning continuous glucose monitoring (FreeStyle Libre Pro, Abbott), alongside conventional arterial or capillary blood glucose measurement. The endpoints were the time below range, defined as the percentage of time with glucose levels < 70 mg/dL. Postoperative hypoglycemia was defined as blood glucose levels below 70 mg/dL or symptomatic events requiring glucose administration.
Results
Eleven patients (50%) experienced postoperative hypoglycemia, with a median onset of 180 min after resection. During a median observation period of 7 days, the mean time below range remained high, ranging from 22% to 37%. Notably, the nocturnal time below range (00:00–06:00) was elevated, reaching 36% to 55%. An increased 7‐day time below range was significantly associated with postoperative hypoglycemia and female sex. The time below range from postoperative Day 5 onwards in patients who experienced early postoperative hypoglycemia remained significantly higher than in those without postoperative hypoglycemia. Perioperative hormonal analysis suggested that the rapid resolution of insulin resistance preceded the recovery of insulin secretion.
Conclusions
This prospective study suggests that prolonged susceptibility to nocturnal glucose dips can persist after the resection of pheochromocytoma and paraganglioma. Patients who develop clinical postoperative hypoglycemia and female sex may serve as indicators for this prolonged susceptibility, suggesting a need for extended monitoring and intervention.