26.MAR.2019 5 MIN READ | 5 MIN READ

What is metabolic surgery and can it treat type 2 diabetes? Dr Melvin Look, general surgeon at Parkway East Hospital, answers frequently asked questions about metabolic surgery and if it is suitable for everyone.

1. What is metabolic surgery? How do you know if you have metabolic syndrome?

Metabolic syndrome
Metabolic surgery refers to surgical procedures used in the treatment of metabolic diseases, especially, type 2 diabetes.

Metabolic syndrome is a cluster of disorders of metabolism that tend to occur together, and is caused by obesity, physical inactivity, increasing age and genetics. Metabolic syndrome greatly increases your risk of developing elevated blood sugar (diabetes), elevated blood pressure (hypertension), elevated blood cholesterol and lipids (dyslipidemia) leading to heart disease and stroke.

Diabetes is a medical condition in which the blood glucose levels remain persistently higher than normal. Obesity is one of the most important factors in the development of diabetes.

2. Who should go for metabolic surgery?

In Singapore, 1 in 3 diabetics are unaware that they have diabetes. Among the diabetics who are aware of their disease, 1 in 3 has poor control of their condition. Persistently elevated blood glucose levels lead to long-term end organ damage to the eyes, kidneys, nerves, heart and peripheral vascular system. This in turn causes blindness, kidney failure, amputation, heart attack and stroke.

Diet and exercise remains the cornerstone in the management of diabetes. Many patients, however, are unable to achieve and maintain a healthy weight, and this in turn can lead to poor control of blood sugar levels despite the use of multiple oral medications and insulin injections.

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 do not want to take lifelong medication and prefer a surgical procedure to reverse diabetes should also consider metabolic surgery.

If you are keen to consider metabolic surgery, you will have to undergo screening procedures to see if you qualify. You must also be willing to make permanent changes to lead a healthier lifestyle.

3. Are there different types of metabolic surgery?

Types of metabolic surgery
The more common metabolic surgery operations are the laparoscopic sleeve gastrectomy and the laparoscopic gastric bypass. These are minimally invasive keyhole procedures similar to the weight loss procedures that are commonly done for obese patients.

Laparoscopic sleeve gastrectomy

This is a keyhole surgical procedure that 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 to bring down blood sugar.

Laparoscopic gastric bypass

This is also a keyhole surgical procedure which creates a small egg-shaped pouch in the upper stomach that 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.

4. What are the benefits of metabolic surgery?

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 – 80% after 18 – 24 months.

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.

A recent large, randomised trial with long-term follow-ups comparing medical therapy with bariatric surgery showed that patients who underwent metabolic surgery have better improvements in quality of life and overall health compared with those who only received medication. One-third of surgical patients achieved complete remission of their diabetes such that blood sugars returned to normal and medication were no longer required.

Results of other medical studies also show that metabolic surgery is a highly effective and durable treatment for type 2 diabetes. Improvements in other metabolic problems such as elevated blood pressure and lipid levels were also consistently found. Surgery was also found to be safe, with no life-threatening complications or deaths.

Metabolic surgery can help prevent medical complications related to diabetes such as kidney failure, diabetic eye disease and vascular problems. This kind of surgery has also been shown to be effective in helping to prevent the onset of diabetes in obese patients who are at high risk of developing this due to their excess weight.

5. How can you prepare for metabolic surgery?

Prepare for metabolic surgery
You will undergo a detailed consultation to discuss what procedure is best for you. You will also undergo blood tests, abdominal ultrasound and gastroscopy to ensure that you are suitable for surgery. Your surgeon will lead a multi-disciplinary team of dieticians, physiotherapists and other medical specialists to ensure that all associated medical problems are managed in the perioperative period.

6. What is recovery like for metabolic surgery?

Surgery is performed under general anaesthesia and takes about 2 hours. You will be put on a liquid diet for a few days better progressing to soft foods. Most patients will stay in hospital for 3 – 5 days. You will be mobilising the day after surgery and the majority of patients will be back to normal activities and exercise after about 2 weeks.

7. Are there side effects or risks?

Metabolic surgery side effects and risks
Metabolic surgery is a very safe operation with a proven long-term track record. The main risks are in the first few days after surgery due to complications such as bleeding and leakage from staple line, infections and medical problems such as respiratory difficulties, deep-vein thrombosis, and adverse reactions to anaesthesia.

You will be guided after surgery to institute lifelong changes to your diet and lifestyle. Long-term complications are rare but weight regain is possible if you persistently overeat.


Article contributed by Dr Melvin Look, general surgeon at Parkway East Hospital

Look Chee Meng Melvin
General Surgeon
Parkway East Hospital

Dr Melvin Look is a general surgeon practising at Parkway East Hospital, Singapore.