Can surgery reverse diabetes?

Developments in the understanding of metabolic surgery are giving new hope to diabetes patients, as Singapore battles an epidemic.

The island has the second-highest proportion of diabetics of all developed nations and the disease now affects over one in 10 of the adult population. As the average age of Singaporeans gets older, it is expected the country will be home to as many as one million diabetics by 2050, out of an anticipated population of 6.5 million.

Diabetes causes blood glucose levels to remain persistently high. It is often associated with obesity and related medical problems such as hypertension and high blood lipid levels, which are also known as metabolic syndrome. Though weight loss, good diet and leading a healthy lifestyle are central to managing diabetes, many patients are unable to maintain a healthy weight. This in turn can lead to poor control of blood sugar levels, despite the use of a range of medications and insulin injections.

“We are very excited about a major trial that was published in 2017 which showed that two surgical procedures could reverse and even stop diabetes on a long-term basis,” said Dr Melvin Look, a gastrointestinal and metabolic surgeon at Parkway East Hospital in Singapore.

The study, conducted by the Cleveland Clinic in the United States proved what metabolic surgeons believed to be the case: that surgically limiting the amount of food that the body digests produces sustainable weight loss that results in improvement in blood sugar levels in type 2 diabetics.

“In addition, these operations also have a complex adaptive effect on our gastrointestinal hormones, which play an important role controlling blood glucose levels. As a result, metabolic surgery has an additional beneficial effect on the control of diabetes beyond weight loss alone,” said Dr Look. 

Earlier forms of weight loss surgery involved the use of gastric bands, whereby a silicon strap is put around the top of the stomach to restrict the intake of food. This technique is not infrequently associated with device-related late complications and has since fallen out of favor.

Two other metabolic surgical techniques have come to prominence and both of these are carried out through minimally invasive surgery. The sleeve gastrectomy coverts the stomach into a long narrow tube about the shape and size of a banana. This limits the amount of food the patient can eat and enhances the effect of intestinal hormones on the control of blood sugar.

“With a sleeve gastrectomy we can alter the way the gut processes food so that it is moved faster from the stomach into the intestines,” said Dr Look.

“When this happens, we find that intestinal hormones are produced to bring down the blood sugar independent of the insulin that is produced from the pancreas.”

This also helps preserve the pancreatic function for longer because an alternative mechanism is employed to control the blood sugar.

The second procedure, gastric bypass, creates a small egg-shaped pouch in the upper stomach which is then connected to the lower part of the small intestine in a “Y” configuration. Food is diverted by this bypass and is only absorbed in a short segment of the intestines.

“With a gastric bypass, the food you put in the stomach goes almost directly into the distant part of the small intestine. There is a lot of malabsorption—this whole section of gut is not used to absorb the nutrients, so malabsorptive procedures like this will help you lose weight very fast,” said Dr Look.

"This profound decrease in nutrient absorption helps to reverse diabetes very effectively as well."

Metabolic surgery should be considered for all poorly controlled diabetics, especially those who are overweight or obese with a body mass index of more than 27. The majority of patients will achieve an excess weight loss of 70-80 percent after 18-24 months.

The results have been so remarkable that this was named by Cleveland Clinic as the top medical innovation for 2013.

“Metabolic surgery is not going to be for everyone with diabetes, but it is showing excellent results in well-selected patients” said Dr Look, "and because it can help prevent the onset of diabetes-related medical complications such as blindness, amputations and kidney failure, we should advocate metabolic surgery early rather than wait for such complications to set in."

Dr Melvin Look is a gastrointestinal and metabolic surgeon at Parkway East in Singapore with a subspeciality expertise in gastrointestinal surgery, therapeutic endoscopy and advanced laparoscopic surgery.