How Weight-Loss Surgery Reverses Type 2 Diabetes
UC Davis, 24th March 2010
Studies about delaying diabetes by weight-loss surgery were carried out in rats. The research was done by a veterinary endocrinologist, Peter Havel.
These findings should help in treating diabetes in human. Diabetes is a chronic disease which makes the body unable to properly metabolize sugar and fat. Diabetes cause serious health problems such as heart disease, blindness and kidney failure.
National Institutes of Health says diabetes affects about 21 million of Americans. The annual cost is more than $150 billion.
Peter Havel said weight-loss surgery is the most effective long-term treatment not only for obesity but also for diabetes.
“It has been thought that reduction of blood sugar, which indicates a reversal of type 2 diabetes, in patients following bariatric surgery was due to post-surgery weight loss,” Havel said. “This study, however, supports the observations from a number of earlier clinical studies reporting that diabetes is often improved prior to substantial weight loss. It also suggests that endocrine changes in hormones produced by the gastrointestinal tract may contribute to the early effects of bariatric surgery, in addition to the later effects of weight loss.”
Other observations show that metabolism is quickly regulated after the surgery.
For severly obese patients, with 80 or more pounds overweight, excess weight is a life-threatening problem.
There are numerous weight-loss procedures available. Gastric bypass is one of the most common, and consists of making the stomach smaller and reroutes the digestive tract. That causes changes in intestinal function and hormones.
Havel and his colleagues set out a hypothesis that bariatric procedure can improve type 2 diabetes, as this increases the flux of unabsorbed nutrients to the far end of the small intestine. This triggers increased secretion of two hormones (glucagon-like peptide-1 and peptide-YY) that control food intake and improve insulin secretion and sensitivity. This helps to stabilize sugar levels.
The researches were carried out in rats that were predisposed to obesity and type 2 diabetes. These conditions in rats are very similar to the human ones.
A short portion of the small intestine was relocated forward in the intestinal tract. Then it was compared how long it took for the animals to develop diabetes compared with a group of rats that had surgery but without rearrangements of the intestines.
The results were that the rats having the ileal interposition surgery developed diabetes 120 days later than the rats in the control group. A year later, 78% of rats in the control group were diabetic while only 38% of the rats that had the ileal interposition procedure had developed diabetes.
Havel said that delaying diabetes in rats by one year will be similar to delaying diabetes in a person by 10 years. This will give enough time to decrease the amount of the complications and reduce health costs that come with treating the disease.
Other results were:
~~ lower fluctuations in blood sugar levels
~~ improved insulin production
~~ decreased levels of cholesterol and triglyceride in the bloodstream
Researchers agree that further studies need to be carried out to better understand what new methods will be able to prevent and treat type 2 diabetes.
