The dramatic rise in the prevalence of obesity and diabetes is associated with
increased mortality, morbidity as well as public health care costs worldwide. The need for
new effective and long-lasting drugs is urgent. Recent research has focused on the role of
incretin in the maintenance of glucose homeostasis through their actions on both α- and β-
cell function. Moreover, increased knowledge of the pathophysiology of diabetes has
contributed to the development of novel drugs, including injectable glucagon-like peptide-1
(GLP-1) mimetics, and oral dipeptidyl peptidase-4 (DPP-4) inhibitors. GLP-1 agonists
mimic the effect of this incretin, whereas DPP-4 inhibitors prevent the inactivation of the
endogenously released hormone. GLP-1 appears to be involved in both peripheral and
central pathways mediating satiety. Clinical trials have shown that two GLP-1 receptor
agonists exenatide and liraglutide have a weight-lowering potential in non-diabetic obese
individuals. Furthermore, they may also hold a potential in preventing diabetes as
compared to other weight loss agents. Both agents offer an effective alternative to the
currently available hypoglycaemic drugs but further evaluation is needed to confirm their
clinical roles and safety. The purpose of this review is to summarize the background of the
incretin, and the roles and side effects of the GLP-1 agonists and DPP-4 inhibitors in
clinical trials. In addition, up-to-date literature on GLP-1 agonists and DPP-4 inhibitors
based clinical therapies will be summarized with a special mention of their weightlowering
properties. In conclusion, the incretin impairment, which seems to exist in both
obesity and diabetes, may link these two pathologies and underlines the potential of incretin
based therapies in the prevention and treatment of obesity and diabetes.
Keywords: Alogliptin, DPP-4 Inhibitors, Exenatide, GLP-1 Agonists, Incretin,
Linagliptin, Liraglutide, Saxagliptin, Sitagliptin, Vildagliptin.
