Abstract
The prevalence of type 2 diabetes in the UK has increased enormously over recent years and is closely associated with obesity and other risk factors for cardiovascular disease. The incretin system, which contributes significantly to the insulin response in healthy individuals, but is impaired in individuals with diabetes, offers a target for the development of agents that address many aspects of diabetes. These agents are broadly split into two categories — the glucagon-like polypeptide-1 (GLP-1) receptor agonists and the dipeptidyl peptidase-4 (DPP-4) inhibitors. The DPP-4 inhibitors sitagliptin and vildagliptin, along with the GLP-1 receptor agonists exenatide and liraglutide are currently approved for use and offer effective glycaemic control with a low risk of hypoglycaemia. GLP-1 receptor agonists may offer further benefits over both DPP-4 inhibitors and conventional therapies, such as reductions in body weight and blood pressure. Here we review the incretin system (with particular reference to GLP-1) and consider the development of these two classes of antidiabetic therapy, discussing the safety and efficacy of some of the latest available GLP-1 receptor agonists and DPP-4 inhibitors.