Effects of octreotide on glycaemic control, glucose disposal, hepatic glucose production and counterregulatory hormones secretion in type 1 and type 2 insulin treated diabetic patients

We studied the effects of continuous subcutaneous infusion of octreotide (100 μ/day for 5 days) on glycaemic values, counterregulatory hormones secretion, hepatic glucose production (HGP) and glucose disposal during an euglycaemic clamp in 7 C-peptide-negative type 1 diabetic patients and 7 C- peptide positive insulin-treated type 2 diabetic patients. In type 1, but not type 2 diabetic patients, octreotide significantly reduced glycaemic values (P <0.005) and also diminished HGP during an euglycaemic clamp (P <0.005). However, insulin stimulated global glucose uptake remained unchanged. GH, glucagon, IGF-I, IGFBP-3 levels, were significantly lowered by octreotide in both type 1 and type 2 diabetic patients whereas cortisol and epinephrine remained unmodified. Moreover in type 2 diabetic patients both basal (P <0.05) and after-meal (P <0.01) C-peptide secretion was reduced by octreotide. These data point to different metabolic effects of octreotide in type 1 versus type 2 diabetic patients with the drug only being able to reduce glycaemic values and HGP in the former but not in the latter subjects. The failure of octreotide to diminish glycaemic values and HGP in type 2 diabetic patients in spite of its ability to lower GH and glucagon may probably depend on temporary blockage of residual endogenous insulin secretion induced by octreotide administration.