Cure

Cures for type 1 diabetes
Main article: Cure for diabetes mellitus type 1
There is no practical cure, at this time, for type 1 diabetes. 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 beta cells in the Islets of Langerhans) has led to the study of several possible schemes to cure this form of diabetes mostly by replacing the pancreas or just the beta cells. Only those type 1 diabetics who have received either a pancreas or a kidney-pancreas transplant (often when they have developed diabetic kidney disease (ie, nephropathy) and become insulin-independent) may now be considered "cured" from their diabetes.
A simultaneous pancreas-kidney transplant is a promising solution, showing similar or improved survival rates over a kidney transplant alone. 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 partly due to the limited number of beta cell donors. Thus far, like any such transplant, it has provoked an immune reaction and long-term immunosuppressive drugs have been 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. This new method, autologous nonmyeloablative HSTC, was recently developed by a research team composed of scientists from the US and Brazil. This was originally tested in mice and in 2007 there was the first trial with fifteen patients.
Recently this trial was continued and 8 more patients were added. In the trial, the researchers implanted diabetes type 1 patients with their own stem cells raised from their own bone marrow. The stem cell transplant led to an appreciable repopulation of functioning insulin-producing beta cells in the pancreas so the patients became insulin free. Most of these patients became insulin independent for a mean period of 18.8 months. At the present time, autologous nonmyeloablative HSCT remains the only treatment capable of reversing type 1 DM in humans.

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.

Cures for type 2 diabetes
Type 2 has had no definitive cure, although recently it has been shown that a type of gastric bypass surgery can normalize blood glucose levels in 80-100% of severely obese patients with diabetes.
The precise causal mechanisms are being intensively researched; its results are not simply attributable to weight loss, as the improvement in blood sugars precedes any change in body mass. This approach may become a standard treatment for some people with type 2 diabetes in the relatively near future. This surgery has the additional benefit of reducing the death rate from all causes by up to 40% in severely obese people.
A small number of normal to moderately obese patients with type 2 diabetes have successfully undergone similar operations.