Glucagon-like peptide-1 in type 2 diabetes: the β-cell and beyond

Many traditional treatments for type 2 diabetes fail to achieve and maintain effective glycaemic control, witnessed by a progressive decline in β-cell functionality and a corresponding rise in blood glucose levels over time. The routine loss of 50% of β-cell function at diagnosis lends new urgency that both diagnosis and treatment initiation take place as early as possible in the course of the disease, before β-cell decline proceeds too far. This review describes the role of the β-cell and glucagon-like peptide-1 (GLP-1) in both normal metabolism and type 2 diabetes, highlights available and anticipated therapies and explores the prospect that certain incretin-derived therapies, which seek to harness the therapeutic potential of native GLP-1, may offer more than glycaemic control alone: they may also facilitate weight loss, improve the cardiovascular profile and, ideally, treat the β-cell in such a way as to modify the natural history of the disease itself.