BACKGROUND: An important metabolic feature of acromegaly is a reduced action of insulin on hepatic gluconeogenesis and peripheral glucose disposal which mediated by growth hormone hypersecretion. Octreotide, a synthetic octapeptide somatostatin analogue exerts complex effects on hormonal and metabolic regulations affecting glucose homeostasis. This study was designed to ascertain the shorterm effect of octreotide on glucose tolerance in acromegaly. METHODS: 10 patients (five men and five women, age 47.9+/-11.8) were injected subcutaneously with octreotide, 100 micrograms for 24 hours. Patients were assessed with respect to growth hormone, glucose, and insulin response to a standard 100 g oral glucose tolerance test (OGTT) before and during the last 2 hour of octreotide infusion. RESULTS: During the therapy, there was significant decrease in mean blood glucose response to OGTT (678.4+/-51.9 vs 581.9+/-47.3 mg/dL/2hr: mean areas under the glucose curve, p=0.01) and mean serum insulin response to oral glucose load was significantly reduced in all patients (339.2+/-106.2 vs 256.7+/-111.3 U/mL/2hr: mean areas under the insulin curve, p=0.01). Using glucose tolerance test criteria three patients of 10 had normal glucose tolerance, four and three had impaired glucose tolerance and diabetes, respectively, at base line. While on octreotide these composition was changed to six patients of NGT, three of IGT and one diabetes. CONCLUSION: We conclude that insulin resistance mediated by GH hypersecretion was improved by shorterm octreotide treatment.
Acromegaly* ; Blood Glucose ; Female ; Gluconeogenesis ; Glucose Tolerance Test ; Glucose* ; Growth Hormone ; Homeostasis ; Humans ; Infusions, Subcutaneous* ; Insulin ; Insulin Resistance ; Male ; Octreotide* ; Social Control, Formal ; Somatostatin