Gastric bypass may help with controlling diabetes and managing weight
As he sat down in my clinic, the patient said: “I want to have a gastric bypass.” This was in 2008. He was 35 years old, weighed 118kg, with a body mass index (BMI) of 43, which put him in the morbidly obese group. I asked him why. He said another doctor had told him it could cure his diabetes.
At that time, laparoscopic gastric bypass surgery had not been performed in Singapore yet. I suggested lap band surgery. He did not want it. His uncle had had it and did not lose any weight. I explained that the lap band was an excellent tool. Many patients had lost a lot of weight with it. One just needs to know how to eat correctly with a band constricting the stomach to a smaller size. It is important to chew slowly and space out each mouthful in order to feel full. But the patient said he might not be able to stop taking insulin after lap band surgery. “I’m fed up with taking insulin and worried about the complications of diabetes. That’s why I want the bypass,” he insisted.
As it turned out, he had been taking care of his mother who had kidney failure from diabetes and had recently died, prompting him to take a long, hard look at his own illness. He had lost 15kg by eating correctly and going to the gym regularly, but had hit a wall after six months. We discussed the details and I scheduled the surgery for Sept 17, 2008.
It was a landmark for me. He was my first such patient since I returned from fellowship training in France, where I had spent a year learning the latest minimally invasive surgical techniques, including that for gastric bypass. The surgery, performed laparoscopically, reduced his stomach to 10 per cent of its original size and bypassed about 1.5m of intestines. This significantly reduced his daily food intake. He left hospital five days after surgery and no longer needed insulin jabs.
Patient does not miss eating fatty and carb-rich foods
A few days later, he called me because he was “hypo-ing”. Basically, his blood sugar was falling below normal – a condition called hypoglycaemia – so he had to stop taking his diabetes tablets. Things then seemed to go well. He lost weight and his blood pressure, cholesterol and kidney function improved. But 18 months later, he cut his little toe and it became infected. Two months after that, I had to amputate it as the infection had spread into the bones and joints of the little toe and would not respond to antibiotics.
Now, almost four years later, he is enjoying a new lease of life. He has lost about 25 per cent of his initial weight and continues to have good control over his diabetic condition. He exercises regularly and eats much less than he used to. I asked him last week if he missed eating the fatty and carbohydrate-rich foods that he used to enjoy so much. Interestingly, he said “no”.
Based on the National Health Survey in 2010, 11 per cent of Singaporeans were obese with a BMI greater than 30. This is significantly higher than the obesity rate in the last study done in 2004, which was 6.9 per cent. Mirroring this rise is the increase in the number of those with diabetes: 11.3 per cent currently, up from 8.2 per cent.
Recent data suggests that bariatric surgery (weight-loss surgery) can help morbidly obese patients with type 2 diabetes mellitus improve their diabetes control, and, in certain cases, to be free of medication. Such exciting results have been reproduced in numerous studies worldwide and led to the new term “metabolic-bariatric surgery” to fully encompass all the benefits of weight-loss surgery.
Profile of metabolic-bariatric surgery patients
In Singapore, the Ministry Of Health’s Obesity Clinical Practice Guidelines (2004) indicate that metabolic-bariatric surgery is a medical intervention in patients with BMI of 32.5 and above with metabolic diseases, such as type 2 diabetes and hypertension.
In our experience with such surgery performed on more than 150 people over the past four years, patients have an average weight loss of about 25 per cent of their original weight, with dramatic and sustained improvements in their metabolic condition.
Within six months, all patients were able to cut their total medication usage by 70 per cent and most patients on insulin have been able to stop it completely. Multiple mechanisms are responsible for this, including restriction of caloric intake, decreased transit time of food passage through the intestines and early stimulation of incretin (digestive) hormones. These hormones are responsible for the sensation of satiety (feeling full) and improve insulin sensitivity and function. However, diabetes is by no means “cured” in all cases.
Non-obese diabetics also do not respond to metabolic-bariatric surgery in the same way. A recent study by Dr Lee Wei Jei in Taiwan – who has the most experience with such surgery in Asia, having done more than 3,000 procedures – showed that patients with a BMI of less than 35 had less improvement in their metabolic condition and diabetes than patients with a BMI over 35.
Thin or mildly overweight patients may have other intrinsic abnormalities in their insulin-producing beta cells leading to the onset of diabetes before significant weight gain. In these patients, weight loss – whether by medical or surgical means – may not be effective in reversing the progression of diabetes.
One must remember that diabetes is a lifelong illness and there is currently a lack of scientific data to determine the long-term efficacy of surgery in controlling it. As in my first patient’s case, the path is not always smooth, so there must be a commitment from both the patient and the doctor to go on this journey together.
Dr Shanker Pasupathy is a Senior Consultant in the Department of General Surgery at Singapore General Hospital (SGH) and the director of its LIFE Centre, which treats lifestyle-related medical conditions. He has special interests in vascular and bariatric surgery and has pioneered a number of complex, minimally invasive procedures.