Can metabolic surgery cure diabetes?

If you have a chronic, progressive medical condition that can lead to serious complications unless it is controlled with a strict diet along with a lifelong intake of daily medication, and possibly even injections, would you consider a surgical operation to cure this?

Strangely enough, we are not talking about a rare esoteric medical condition, but yet surgery for diabetes is still little known in Singapore and Asia.

Diabetes is one of the major health problems here and the prevalence is expected to increase over the next few decades. In fact, it is so important that Prime Minister Lee Hsien Loong chose to discuss this in his National Day Rally in 2017. He said, “Overall, 1 in 9 Singaporeans have diabetes. But the prevalence increases as you age. If you are my age, over 60, 3 in 10 Singaporeans have diabetes. If you break it down by race, among the Chinese, 2.5 in 10 over 60 will have it; among the Malays, half; and for the Indians, 6 in 10. So this is a very serious problem, and for the Malays and Indians, actually a health crisis.” There are an estimated 440,000 Singapore residents with diabetes currently and probably many more pre-diabetics who have glucose intolerance.

What is Diabetes?

Diabetes occurs when your pancreas is unable to produce adequate amounts of the hormone insulin, or when your body is unable to respond to the insulin in the right way, leading to elevated blood sugar levels. Diabetes is also strongly associated with Metabolic Syndrome, the cluster of inter-related metabolic problems, which includes hypertension, high lipid levels and, most importantly, obesity. In fact, obesity is one of the major risk factors in the development of glucose intolerance and diabetes.

Local studies have found that 1 in 3 people with diabetes are undiagnosed, and another 1 in 3 of those being treated for diabetes does not achieve adequate blood sugar control. This shows that many people living with harmful levels of blood sugars can be without any tell-tale symptoms. Untreated diabetes, and poorly

controlled diabetes, results in a chronic elevation of your blood sugar levels. This is harmful and leads to end organ damage, such as kidney failure, blindness, heart disease and limb amputations.

It is not surprising that many diabetics will, over the years, require the use of multiple drugs, some of which help to stimulate the pancreas into producing more insulin. Eventually, however, the pancreas may fail to produce insulin completely and artificial insulin in the form of injections may be required.

Diet control is another important cornerstone of diabetes management. In fact, it is well proven that weight loss in obese diabetics can contribute to blood sugar control by decreasing the “insulin resistance” that is associated with fatty adipose tissue.

As a gastrointestinal surgeon, I have been doing Bariatric Surgery for the past 20 years to help obese patients achieve sustainable weight loss. We were quite astonished in those early days to find the profound positive impact our surgery had on the blood sugar control of those obese patients who were also diabetic. This often happened immediately after surgery and before significant weight loss could have altered their insulin resistance.

The exact scientific explanation for this was elusive initially, but it gave rise to the exciting field of Metabolic Surgery; surgical procedures used in the treatment of metabolic diseases, especially, type 2 diabetes. The link between gastrointestinal surgery and blood sugar control has now been well studied. It is a complex one that involves gut hormones, bile acids, gut microbiota, and intestinal nutrient sensing. As such, it may well be that instead of drugs acting on the control of blood sugar, altering the gastrointestinal tract surgically may be a better biological target for interventions to treat diabetes.

How does Metabolic Surgery work?

Metabolic Surgery should be considered for all poorly controlled diabetics, especially those who are overweight or obese. As a guideline for Asian patients, we usually use a Body Mass Index (BMI) of more than 27 kg/m2. Diabetic patients who can be controlled with medication, but do not want to take lifelong medication, should also consider Metabolic Surgery.

The most common Metabolic Surgery operations are the Laparoscopic Sleeve Gastrectomy and the Laparoscopic Gastric Bypass. We tend to favor the sleeve procedure in Asian patients as it is a very safe and effective operation. This is a keyhole surgical procedure that converts 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 to bring down blood sugar. The operation takes two hours and patients stay in hospital for 3 days after surgery. Recovery is quick and risk of possible complications are very low.

Multiple clinical trials have now showed that Metabolic Surgery can improve blood sugar levels better than any medication or lifestyle intervention, and can result in long-term remission for patients with mild to severe diabetes. Surgery also lowers the future risk of diabetes-related complications, including cardiac, renal, and neurological adverse events.

For obese diabetics, Metabolic Surgery results in a significant and sustainable long term weight loss. The majority of patients will achieve an excess weight loss of about 70 to 80% after 18 to 24 months. Associated medical conditions, such as hypertension and dyslipidaemia will also improve, and there is a sustainable positive impact on the overall quality of life in patients after surgery.

Earlier this year, the long-term results of a randomised controlled trial in Europe was published in the reputable Lancet medical journal. Over one-third of surgically treated patients remained diabetes-free throughout the 10-year period of the trial. This led the authors to declare that “in the context of the most rigorous type of clinical investigation, a “cure” for type 2 diabetes can be achieved.”

Metabolic surgery is arguably the most effective available therapy we have now for diabetes. This radical shift is already supported by clinical guidelines published by the American Diabetes Association and endorsed by 45 professional societies internationally. Whether you choose to call it a reversal of diabetes, a remission, or even a “cure”, it is an empowering and life-changing possibility for diabetic patients. All we need now is more public awareness and a radical change in the mind-set of patients and the physicians involved in their care.

Dr Melvin Look is the Director of PanAsia Surgery in Mount Elizabeth Hospital, Mount Elizabeth Novena Hospital and Parkway East Hospital. He is a Consultant Surgeon in Gastrointestinal, Laparoscopic and Obesity Surgery, and has a special interest in Endoscopy and treatment of Digestive Diseases. He underwent various training awards at the National Cancer Center Hospital in Tokyo, Royal Infirmary of Edinburgh UK, Mount Sinai Medical Centre New York, and Washington Cancer Institute in Washington DC.