Insulin tolerance test and tolbutamide tolerance test in acromegaly

ABSTRACT

Five healthy normal volunteers and seven nor diabetic aeromegalic patients were studied during the last 10 years augmented I.T.T .and i.v. tolbutamide test were done. Results were compared to the normal controls. All the 7 patients showed abnormal curves and a high in sulin resistance index. The drop of blood sugar after i.v. tolbutamide was less than 20%; of the starting level, indicating resistance to endogenous insulin. Also the ratio between the nadirs in Tolbutamide test and augmcntcr I.T.T. was more than 2.5 1, compared to the ratio in normal controls of less than 2 1. In absence of facilities for growth hormone radio-immuno assay in most of our hospitals, the importance of these indirect measures for growth hormone activity is stressed