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 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 (when
they have developed diabetic 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. 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. 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 diabetes can be cured by one type of gastric
bypass surgery 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
occurs. 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. 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 the 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.