To describe the efficacy and safety of the glucagon-like peptide 1 (GLP-1) analogues exenatide and liraglutide, and the dipeptidyl peptidase-4 (DPP-4) inhibitors vildagliptin and sitagliptin, registered in the Netherlands for treatment of type 2 diabetes mellitus (DM2).
The Medline database was searched up to and including August 2009 for systematic reviews and randomised trials with a minimum duration of 12 weeks in patients with DM2. Two authors independently selected the studies based on the title, abstract and, if necessary, the full text.
In addition to 1 systematic review on GLP-1 analogues and 1 review on DPP-4 inhibitors, 10 studies on DPP-4 inhibitors and 16 studies on GLP-1 analogues were included. According to these studies, the DPP-4 inhibitors sitagliptin and vildagliptin gave a mean HbA1c reduction of 0.7% and 0.6% respectively. GLP-1 analogues led to a mean HbA1c reduction of 1%, which is comparable to insulin therapy. Sitagliptin was associated with a slight increase in the number of upper respiratory tract infections. In a large number of patients, GLP-1 analogues were associated with gastrointestinal complaints. DPP-4 inhibitors were associated with a small weight gain, compared with weight loss in patients treated with GLP-1 analogues. Data on microvascular and macrovascular complications, as well as data on mortality, are not yet available in either group.
GLP-1 analogues regulate blood glucose levels as effectively as the current glucose-lowering agents; DPP-4 inhibitors are less effective. GLP-1 analogues lead to a clear weight reduction while DPP-4 inhibitors cause slight weight gain. Data on efficacy and safety in the longer term are not yet available.