ABDOMINAL surgery is a radical way of losing weight, but could it also cure type 2 diabetes?

Duodenal exclusion is a form of gastric bypass surgery in which the upper small intestine or duodenum is removed, so that the stomach feeds directly into the mid-small intestine. This reduces the amount of time the body has to absorb calories from food, meaning people lose weight.

Surgeons performing duodenal exclusions on obese people with diabetes had noticed that in around 98 per cent of cases the patients’ diabetes spontaneously vanished a few weeks after surgery – too soon to be accounted for by weight loss.

Now a team of Italian, Brazilian and French doctors has performed duodenal exclusions on seven people with type 2 diabetes who were classified as normal weight to moderately obese, to see if it has a similar effect. Nine months after surgery, the first two people they operated on are both free of anti-diabetic medication. Both experienced dramatic reductions in their blood sugar and insulin levels in the month following surgery – before any weight loss took place (Surgery for Obesity and Related Diseases, DOI: 10.1016/j.soard.2007.01.009). It is too soon to report on the other five patients.

Type 2, or adult-onset, diabetes is characterised by insulin resistance. This means the body can produce insulin – which would normally encourage liver and muscle cells to take up glucose from the blood – but cells no longer respond to it.

Francesco Rubino, a surgeon at the Catholic University of Rome, Italy, who was involved in the study, believes that the duodenum may be the source of a signal that can ultimately cause insulin resistance. “This molecular signal, which should be secreted in response to nutrients’ passage, is possibly exaggerated in diabetic patients or produced in an untimely fashion, disturbing the regulation of insulin and blood glucose levels,” says Rubino, who will present his results at a meeting of the International Federation for the Surgery of Obesity in Porto, Portugal, next week.

If his assumption is correct, bypassing the duodenum could silence this “insulin resistance signal”, thus re-establishing a normal balance between insulin and sugar. Previous studies in rats have shown that the effects of duodenal exclusion on diabetes are independent of the amount of food eaten by the rats, suggesting that dietary changes are not responsible for the improvement.

Conversely, people who do not have diabetes but undergo gastric bypass surgery for peptic ulcers or cancer, say, often see a deterioration in their glucose control, reinforcing the idea that the duodenum is involved in maintaining normal glucose levels, Rubino says. Until recently, the pancreas was believed to be the key player in glucose regulation.

According to Rubino, duodenal exclusions in people with diabetes who are not morbidly obese have also been performed by groups in Mexico, Peru, Dominican Republic and India with similar outcomes, although the results have not been published. Clinical trials are now starting in some of these countries, as well as in China, Japan, the US, Italy and Belgium.

While it may be five years before we have a clear idea of exactly who should undergo surgery, Rubino and several other doctors have already submitted a proposal to the American Association of Clinical Endocrinologists (AACE), suggesting it recommends the use of duodenal exclusion surgery to treat type 2 diabetes.

Richard Hellmann, president of the AACE, says the association is studying the evidence, but has not yet reached a decision. “Diabetes surgery may be an interesting option for some patients, but there aren’t yet any long-term data on its benefits and risks in large numbers of people,” he says. He adds that treatments already exist for diabetes that may be much safer, as well as far less expensive. However, current treatments rarely cause complete remission of diabetes, Rubino says.

For the time being, Tracy Kelly of Diabetes UK stresses that the key ways to manage and possibly prevent type 2 diabetes are by eating a healthy balanced diet and taking regular exercise.

Edit: Forgot to mention that this is not my article, this is a NewScientist magazine publication and premium article, i just put it here for free

Share this: Twitter

Facebook

Like this: Like Loading...