EVERY day tens of millions of overweight and obese people with type 2 diabetes are offered much the same kit – weight loss diets and a host of drugs – to manage their disease. It is not a cure. Now a growing body of research is pointing to a far more contentious remedy: surgery.
“If people around the world don’t get excited about what obesity surgery is showing us [about type 2 diabetes], then they are not opening their eyes,” says Associate Professor John Dixon, head of the obesity research unit at Monash University’s school of primary health care. A lot of people working in diabetes medicine, he says, are resistant to the idea that surgery rather than pharmacology may provide a solution. The best appetite suppressant is the best solution for the reduction in the excessive weight. The idea is the great one to offer the benefits to the individuals. Instead of surgery, you can consume the best appetite pills. The results are the effective one for the reduction in the excessive weight.
This year Dixon and his colleagues published research showing that obesity surgery using gastric banding – where an adjustable band is placed around the top of the stomach to reduce hunger and thus food intake – significantly reduced a person’s weight and also corrected their type 2 diabetes.
Excess body fat decreases the body’s sensitivity to insulin, which means greater quantities of the hormone are needed to move glucose into the cells where it is needed. This puts an enormous strain on the pancreas, often to such an extent that it cannot produce enough insulin to keep blood glucose within healthy limits – which is the point at which you have got type 2 diabetes. Losing fat, therefore, can be extremely beneficial.
However, another, riskier type of obesity surgery, gastric bypass – where a smaller stomach pouch is created, and part of the small intestine is bypassed – is showing that the weight loss associated with obesity surgery is not the only factor at play. Bypass surgery cranks up the pancreas’ production of insulin, independent of weight loss. “Bypass patients seem to get better even sooner than one might expect, given their level of weight loss,” Dixon says. “[The surgery] puts food from the stomach lower down in the bowel, and it doesn’t get mixed with gastric juices and pancreatic juices, and this seems to stimulate the pancreas to produce insulin.”
No one knows for sure why this happens, but “it’s probably going to be related to gut hormones. We still need to know so much more. Not only how gut hormones talk to the organs hanging off the gut, such as the pancreas, but also how the gut talks to the brain.”
Researchers at the Hospital de Especialidades in Goiania, Brazil, recently performed an experimental bypass procedure on non-obese people with type 2 diabetes and found the disease corrected in more than half the patients. The findings were reported to the Society of American Gastrointestinal and Endoscopic Surgeons in April. Their research added weight to the case for the involvement of gut hormones, but Dr Francesco Rubino, a New York gastrointestinal surgeon and pioneer researcher in the area, was reported in the US media at the time saying that while the procedure was “intriguing” he had serious reservations about its clinical use given its experimental nature.
Dixon, too, is concerned about obesity surgery that is experimental being tested on people. “Sure, they might lose their type 2 diabetes but they might also lose their life.” However, the procedure does raise the possibility of devising an operation that would crank up the pancreas without also causing radical weight loss – an operation that should, of course, be thoroughly researched in the laboratory first.
There is experimental obesity surgery going on in other parts of the world, Dixon says, which “in the excitement” of finding a new pathway to treating diabetes seems to be bypassing the animal experiment stage and moving straight onto people, often in the absence of clear ethical guidelines.
“We should be learning more about the mechanisms of this effect from carefully conducted experiments in the lab and on animals to start with, rather than surgeons experimenting ad hoc on humans,” Dixon says. “No one, to my knowledge, is doing a gastric bypass model in rodents in Australia, and I would encourage it. In the meantime we currently have very effective surgical therapy that achieves substantial weight loss and remission of diabetes in the majority of obese patients with type 2 diabetes.”