New developments in the treatment of type 1 diabetes mellitus.

Abstract

Treatment of type 1 diabetes mellitus has made tremendous advances within the last decades. With concern to insulin delivery there are two promising new approaches. One is the intrapulmonary insulin delivery which has become feasible by the development of new inhalation devices which provide a sufficient degree of intrapulmonary drug retention. Also oral insulin delivery seems feasible when surface active substances are used to cross the mucosal membrane in the gut. Clinical research has also focussed on coatings for the insulin molecules to solve the problem raised by the proteolytic activity of the digestive system. A very new agent produced by a fungus called Pseudomassaria has been demonstrated to reverse the clinical signs of diabetes mellitus in mice. The compound diffuses through the cell membrane, binds to the inner part of the insulin receptor and activates the insulin typical biological effects. Nowadays a variety of insulin analogs are designed and tested for their clinical use. By shifting the isoelectric point towards to a slightly acidic pH, HOE 901 precipitates at physiologic pH resulting in a constant and peakless insulin delivery. NN 304 is a 14-carbon aliphatic fatty acid acylated analog that binds to serum albumin resulting in a flatter time-action profile than NPH insulin. Also rapid acting insulin analogs are or will be launched in the near future aiming to ensure an improved postprandial glucose regulation. Glucagon-like peptide-1 (GLP-1) improves metabolic control by a variety of effects, e.g. the enhancement of insulin secretion and inhibition of glucagon secretion. Moreover, GLP-1 reduces food and water intake controlled by the brain, and inhibits gastric emptying. A disadvantage of GLP-1 is its very short half-life. Novel derivatives with the beneficial effects of GLP-1 but a better resistance against degradation have been designed. In addition substances have been developed inhibiting GLP-1 degradation or augmenting GLP-1 release from its abundant endogenous pool. Finally, there is a variety of interesting approaches aiming to improve or ease blood glucose self-monitoring. One is the development of subcutaneous catheters for continuous blood glucose control. In another system reverse iontophoresis is used for sampling interstitial fluid which reflects capillary blood glucose levels. Instead of using an electric current, a brandnew system creates micropores in the skin by a laser ablation system. Through these micropores a specific device performs a mild suction to obtain intersitial fluid. Further systems which measure blood glucose by near infrared spectroscopy are still investigated in order to improve their technical function and to reduce their weight. This article intends to give an overview over the new developments in the treatment and management of type-1-diabetes mellitus.