Type-2 diabetes is a metabolic disorder that is increasing rapidly in the developed world. The disease is caused by reduced production of insulin by the pancreas and /or reduced responsiveness to insulin by cells in the body, particularly fat, muscle and liver cells. Reduced insulin activity causes higher blood glucose levels as well as other complex metabolic changes, leading eventually to organ damage with increased morbidity and mortality.
A number of medicines are used to treat type-2 diabetes; these include metformin, sulphonyl ureas, and thiazolidinediones. More recently, inhibitors of dipeptidyl peptidase-4 (DPP-4) have emerged as an alternative method of treatment. DPP-4 inhibitors act by increasing levels of the gastrointestinal hormones, incretins, which increase the amount of insulin released by the pancreas, inhibit glucagon release and also slow gastric emptying.
New data has been presented showing that Januvia™ (sitagliptin), in combination with metformin, provided significant glucose lowering over two years. In separate studies, addition of Januvia™ to regimens based on thiazolidinediones also led to improved blood sugar control. Januvia™ was the first DPP-4 inhibitor to be approved for the treatment of diabetes in the US and Europe although several other inhibitors are in varying stages of development.