Incretin-based therapy: a powerful and promising weapon in the treatment of type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a progressive multisystemic disease that increases significantly cardiovascular morbidity and mortality. It is associated with obesity, insulin resistance, beta-cell dysfunction, and hyperglucagonemia, the combination of which typically leads to hyperglycemia. Incretin-based treatment modalities, and in particular glucagon-like peptide 1 (GLP-1) receptor agonists, are able to successfully counteract several of the underlying pathophysiological abnormalities of T2DM. The pancreatic effects of GLP-1 receptor agonists include glucose-lowering effects by stimulating insulin secretion and inhibiting glucagon release in a strictly glucose-dependent manner, increased beta-cell proliferation, and decreased beta-cell apoptosis. GLP-1 receptors are widely expressed throughout human body; thus, GLP-1-based therapies exert pleiotropic and multisystemic effects that extend far beyond pancreatic islets. A large body of experimental and clinical data have suggested a considerable protective role of GLP-1 analogs in the cardiovascular system (decreased blood pressure, improved endothelial and myocardial function, functional recovery of failing and ischemic heart, arterial vasodilatation), kidneys (increased diuresis and natriuresis), gastrointestinal tract (delayed gastric emptying, reduced gastric acid secretion), and central nervous system (appetite suppression, neuroprotective properties). The pharmacologic use of GLP-1 receptor agonists has been shown to reduce bodyweight and systolic blood pressure, and significantly improve glycemic control and lipid profile. Interestingly, weight reduction induced by GLP-1 analogs reflects mainly loss of abdominal visceral fat. The critical issue of whether the emerging positive cardiometabolic effects of GLP-1 analogs can be translated into better clinical outcomes for diabetic patients in terms of long-term hard endpoints, such as cardiovascular morbidity and mortality, remains to be elucidated with prospective, large-scale clinical trials

The Clinical Efficacy and Safety of Glucagon-Like Peptide-1 (GLP-1) Agonists in Adults with Type 2 Diabetes Mellitus

Objective To review the efficacy and safety of glucagon-like peptide-1 (GLP-1) agonists to determine their role in type 2 diabetes mellitus (T2DM). Data Sources A Medline search was conducted using the keywords exenatide, liraglutide, glucagon-like peptide-1, type 2 diabetes mellitus, hyperglycemia, pharmacokinetics, pharmacology and safety. Study Selection All identified articles written in English were evaluated with priority given to controlled, randomized trials including human data. References of identified published trials were reviewed for additional trials to be included in the review. Data Synthesis Exenatide and liraglutide are GLP-1 agonists approved for the treatment of T2DM. Several randomized, active and placebo controlled trials examining the efficacy and safety of exenatide and liraglutide both as monotherapy and in combination therapy have been conducted. Both agents have demonstrated improved glycemic control in addition to weight loss and increased beta-cell function. The most common adverse effects are gastrointestinal in nature and appear to be transient. Conclusion It appears exenatide and liraglutide are safe and effective in the treatment of T2DM and may exhibit effects that make them preferred over other anti-diabetic medications