Glucagon Clearance Is Preserved in Type 2 Diabetes

Abstract

Hyperglucagonemia is a common observation in both obesity and type 2 diabetes, and the etiology is primarily thought to be hypersecretion of glucagon. We investigated whether altered elimination kinetics of glucagon could contribute to hyperglucagonemia in type 2 diabetes and obesity. Individuals with type 2 diabetes and preserved kidney function (eight with and eight without obesity) and matched control individuals (eight with and eight without obesity) were recruited. Each participant underwent a 1-h glucagon infusion (4 ng/kg/min), achieving steady-state plasma glucagon concentrations, followed by a 1-h washout period. Plasma levels, metabolic clearance rate (MCR), half-life (T1/2), and volume of distribution of glucagon were evaluated, and a pharmacokinetic model was constructed. Glucagon MCR and volume of distribution were significantly higher in the type 2 diabetes group compared with the control group, while no significant differences between the groups were found in glucagon T1/2. Individuals with obesity had neither a significantly decreased MCR, T1/2, nor volume of distribution of glucagon. In our pharmacokinetic model, glucagon MCR associated positivelywith fasting plasma glucose and negatively with body weight. In conclusion, our results suggest that impaired glucagon clearance is not a fundamental part of the hyperglucagonemia observed in obesity and type 2 diabetes.