Differential effects of GLP-1 receptor agonists on components of dysglycaemia in individuals with type 2 diabetes mellitus

Metabolic consequences of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are the result of enhanced glucose-stimulated insulin secretion, inhibition of glucagon release, delayed gastric emptying and increased satiety. These attributes make GLP-1 agonists a treatment option in type 2 diabetes mellitus (T2DM). To optimise treatment choice, a detailed understanding of the effects of GLP-1 RAs on glucose homeostasis in individuals with T2DM is necessary. Although the various GLP-1 RAs share the same basic mechanisms of action, differences in pharmacokinetic/pharmacodynamic characteristics translate into differential effects on parameters of glycaemia. Head-to-head comparisons between long-acting non-prandial (liraglutide once daily and exenatide once weekly) and shorter-acting prandial (exenatide twice daily and lixisenatide once daily prandial) GLP-1 RAs confirm their differential effects on fasting plasma glucose (FPG) and post-prandial glucose (PPG). Liraglutide once daily and exenatide once weekly demonstrate greater reductions in FPG but lesser impacts on PPG excursions plasma than exenatide twice daily. Prandial GLP-1 RAs have a profound effect on post-prandial glycaemia, mediated by delaying gastric emptying, which is not subject to the tachyphylaxis occurring due to the sustained elevated plasma GLP-1 concentrations after treatment with long-acting GLP-1 RAs. Lixisenatide once-daily prandial, in contrast to liraglutide, strongly suppresses post-prandial glucagon secretion, further contributing to the more pronounced PPG-lowering effect found with lixisenatide. Evidence suggests that the GLP-1 RAs that predominantly target the prandial glucose excursions, such as exenatide twice daily and lixisenatide once-daily prandial, are therefore best used as combination therapy with basal insulin and will form an important new treatment option for individuals with T2DM. Crown Copyright (C) 2013 Published by Elsevier Masson SAS.