Two new studies are shedding light on just how certain weight-loss surgeries can help patients lose weight and even potentially reverse diabetes.
The first study showed that the vast majority of obese patients with diabetes who underwent gastric bypass and sleeve gastrectomy operations experienced a dramatic improvement in diabetes control and symptoms within three years of the surgery. Researchers compared blood-sugar control in 150 patients who were randomized to surgical procedures or to management with medications alone.
After three years, over 90% of surgical patients no longer had to take insulin to control their diabetes. In addition, over a third of the patients who had undergone gastric bypass surgery and about a fifth of people who received a sleeve gastrectomy were able to stop all medications to lower blood sugar, effectively reversing their diabetes. Over the same period, only 5% of patients in the medical group were able to achieve ideal blood-sugar control.
Usually, to qualify for bariatric surgery, people have to have failed to lose weight through diet and exercise and have a BMI of 40 or higher, or a BMI between 35 and 40 and a serious comorbid illness, such as type 2 diabetes. Those with severe, uncontrollable diabetes may be able to get the surgery at even lower BMIs.
While doctors have long thought that weight-loss surgeries worked mostly by reducing the size of the stomach, a second study is now showing that these procedures have other previously unrecognized weight-loss effects. New animal research that was also published this month showed that vertical sleeve gastrectomies trigger a chain of signaling cascades in the digestive system that up-regulate metabolic function, increase fat breakdown and help regulate appetite. In addition, these changes may also promote the growth of healthy gut bacteria and interfere with bad bacteria that can lead to weight gain and metabolic problems.