GLUCOSE HOMEOSTASIS IN PATIENTS WITH PHEOCHROMOCYTOMA
Abstract
Background and Aims. Previous studies have shown that impaired glucose tolerance is present in patients with pheochromocytoma with a prevalence of 25– 75%. The aim of this study was to examine glucose tolerance in 12 patients with pheochromocytoma, before and after medical and surgical treatment. Material and Methods. We evaluated 12 patients aged between 44 and 60 years with confirmed pheochromocytoma. Plasma insulin, fasting blood glucose and 2h glucose levels during the oral glucose tolerance test (OGTT) were measured before and three months after surgical removal of the tumor. Results. Surgical removal of the tumor generated significant changes in plasma and urinary metanephrines (plasma normetanephrine 191.15±13.22 pg/ml after treatment vs. 792.54±86.74 pg/ml at baseline, p<0.0001, plasma metanephrine 86.69±4.48 pg/ml vs. 363.62.±21.69 pg/ml, p<0.0001, urinary normetanephrine 718.54±37.59 μg/day after treatment vs. 1855.77±116.54 μg/day at baseline and urinary metanephrine of 258.31±34.00 μg/day vs. 745.38±65.14 μg/day, p<0.0001) but not in insulin, fasting and 2h glucose levels during OGTT. Conclusion. In our study, the prevalence of impaired glucose tolerance in patients with confirmed pheochromocytoma was 8.33% (1 patient with a previous family history of diabetes). After surgical removal of the tumor, normalization of mean glucose levels of OGTT was not achieved.