Cures for Type 1 Diabetes
There is no practical cure now 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 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 has been done in mice, and 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.
Cures for Type 2 Diabetes
Type 2 has had no cure. But, very recently, it has been shown that a type of gastric bypass surgery can normalize blood glucose levels in 80-100% of severely obese patients. The effect is not due to weight loss because it usually occurs within days of surgery, which is before significant weight loss happens. The pattern of secretion of gastrointestinal hormones is changed by the bypass and removal of the duodenum and proximal jejunum, which together form the upper (proximal) part of the small intestine. The precise causal mechanisms are being intensively researched. This approach may become a standard treatment for some people with type 2 diabetes in the near future. One hypothesis is that the proximal small intestine is dysfunctional in type 2 diabetes, its removal eliminates the source of an unknown hormone that contributes to insulin resistance. This surgery has been widely performed on morbidly obese patients and has had the additional benefit of reducing the death rate from all causes by up to 40%. A small number of normal to moderately obese patients with type 2 diabetes have successfully undergone similar operations.
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