Diabetes mellitus in phaeochromocytoma. Fasting blood glucose levels before and after surgery in 60 patients with phaeochromocytoma.

Sixty patients undergoing operation for phaeochromocytoma were investigated in the pre- and postoperative states with respect to fasting blood glucose levels. When 6 previously known or suspected diabetics were excluded, preoperative diabetes (fasting blood glucose levels greater than or equal to 7.0 mmol/l) were found in 3 of 13 (23%) with sustained hypertension, in 6 of 12 (50%) with sustained hypertension associated with paroxysms and in 4 of 24 (17%) with paroxysmal hypertension. None of the 5 patients with atypical clinical symptoms had glucose levels greater than or equal to 7.0 mmol/l. In the groups of patients with particularly high urinary excretion of catecholamines and vanilmandelic acid higher blood glucose levels were also found. The postoperative blood glucose levels in the follow-up study were normal and less than 5.8 mmol/l in all cases except in 3 of the 4 still living patients with a previously known diabetes and in 1 patient with a malignant tumour. Thus, manifest diabetes, defined as fasting glucose levels greater than or equal to 7.0 mmol/l, is frequently present in patients with phaeochromocytoma (24% in the present study) and the diabetes is reversed by removal of the tumour.