In a morbidly obese person with diabetes, weight loss surgery can dramatically reduce blood sugar levels--and even cure the disease.
Bariatric surgery aids weight loss in many ways, including restriction of food intake, malabsorption of food, or hormonal effects. Weight loss, in turn, can lead to many health benefits, including improvements in blood pressure, joint pain and sleep apnea.
But one of the most striking results is the effect that bariatric surgery can have on Type 2 diabetes. The surgery improves the condition in nearly 90 percent of patients and actually causes it to go into remission in 78 percent, according to the American Society for Metabolic and Bariatric Surgery.
“Medical science has known about these effects for years, but in the past decade, research has begun to help us understand their causes,” says Alan Saber, MD, Director of the Bariatric and Metabolic Surgery program at Newark Beth Israel Medical Center. “Researchers are looking into the possibility of postsurgery changes in the bacteria of the intestine, called gut microbiota, and possible changes in signals between the brain and the gastrointestinal tract.
“In addition, we now believe that part of the improvement in Type 2 diabetes is due to changes in gut hormones that occur after surgery.”
The hunger hormone
While the gastrointestinal (GI) tract produces a number of gut hormones, an especially significant one is ghrelin— known as “the hunger hormone” because it stimulates appetite. Ghrelin is mainly produced by specialized cells in the fundus (upper part of the stomach). Levels of ghrelin in a patient’s body decrease after some types of bariatric procedures, among them gastric bypass (in which a small stomach pouch is created and connected directly to the small intestine) and sleeve gastrectomy (in which the fundus is removed). “With gastric bypass, the chance for significant improvement in Type 2 diabetes is 80 to 85 percent; with sleeve gastrectomy, it’s about 75 percent,” says Dr. Saber.
Reduced ghrelin leads to reduced hunger, which, of course, aids in weight loss. In addition, when excess body fat is reduced, so is the body’s resistance to insulin, the hormone that regulates the amount of sugar in the blood. But even deeper metabolic processes, not yet completely understood, seem to be taking place. “We’re seeing improvement in Type 2 diabetes very soon after surgery, independent of weight loss,” says Dr.
Saber. “Something else is going on.”
Weight loss surgery is not for every patient who is obese and has Type 2 diabetes. “For some patients, dietary and lifestyle management will be prescribed first,” says Dr. Saber. “However, for patients with a Body Mass Index [BMI] greater than 35, bariatric surgery is more likely to be recommended. In either case, lifelong follow-up with diet, exercise and support after bariatric or metabolic surgery is very important.”
Learn more about bariatric and metabolic surgery at Newark Beth Israel Medical Center.