Does glibenclamide influence the clearance of insulin and glucose uptake in patients with type 2 diabetes mellitus

Sulphonylureas have been proposed to decrease the clearance of insulin based on the finding that they increase peripheral insulin concentrations more than C-peptide concentrations. However, direct evidence for such an effect has so far been lacking. The aim of this study was to investigate whether glibenclamide affects clearance of insulin in Type 2 diabetic patients. Nine patients with Type-2 diabetes participated in the study. Insulin clearance and glucose metabolism was assessed with a 240 min euglycaemic insulin clamp in combination with infusion of somatostatin (400μgh−1) to completely suppress endogenous insulin secretion. Either saline or glibenclamide was infused throughout the clamp in random order. During both the glibenclamide and the saline protocol the C-peptide level declined to < 0.07nmoll−1 within 150 min, indicating that insulin secretion was completely suppressed. However, peripheral clamp insulin concentrations remained similar during both saline and glibenclamide protocols (3374±258 vs...