Sunday, September 9, 2007

Curing Diabetes

Curing diabetes

There is no practical cure now for type 1 diabetes, but type 2 diabetes can be cured by gastric bypass surgery.

Gastric bypass surgery cures type 2 diabetes in 80-100% of obese patients, and in some non-obese patients, usually within days after surgery. This is not an effect of weight loss, since it occurs long before weight loss.[21] After gastric bypass surgery for obesity, the death rate from all causes is reduced by up to 40%

The fact that type 1 diabetes is due to the failure of one of the cell types of a single organ with a relatively simple function (i.e. the failure of the islets of Langerhans) has led to the study of several possible schemes to cure this form diabetes mostly by replacing the pancreas or just the beta cells.

Only those type 1 diabetics who have received a kidney-pancreas transplant (when they have developed diabetic nephropathy) and become insulin-independent may now be considered "cured" from their diabetes. Still, they generally remain on long-term immunosuppressive drugs and there is a possibility that the immune system will mount a host versus graft response against the transplanted organ.

Transplants of exogenous beta cells have been performed experimentally in both mice and humans, but this measure is not yet practical in regular clinical practice. Thus far, like any such transplant, it has provoked an immune reaction and long-term immunosuppressive drugs will be needed to protect the transplanted tissue.An alternative technique has been proposed to place transplanted beta cells in a semi-permeable container, isolating and protecting them from the immune system. Stem cell research has also been suggested as a potential avenue for a cure since it may permit regrowth of Islet cells which are genetically part of the treated individual, thus perhaps eliminating the need for immuno-suppressants. However, it has also been hypothesised that the same mechanism which led to islet destruction originally may simply destroy even stem-cell regenerated islets. A 2007 trial of 15 newly diagnosed patients with type 1 diabetes treated with stem cells raised from their own bone marrow after immune suppression showed that the majority did not require any insulin treatment for prolonged periods of time.

Microscopic or nanotechnological approaches are under investigation as well, in one proposed case with implanted stores of insulin metered out by a rapid response valve sensitive to blood glucose levels. At least two approaches have been demonstrated in vitro. These are, in some sense, closed-loop insulin pumps.