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Metabolic Surgery – A randomized controlled trial

In reference to a recently published randomized controlled trial featured in the Lancet Diabetes - Endocrinology , co-author Professor Paul O'Brien, discusses the potential of metabolic surgery...

The report of our recent randomized controlled trial in Lancet Diabetes - Endocrinology1  is a report of metabolic surgery. None of the patients in this trial was obese and we were not seeking weight loss as our primary endpoint. They all had type 2 diabetes and our primary aim was remission of diabetes. We believe this is the first RCT showing the effectiveness of pure metabolic surgery.

The term Metabolic Surgery is in the ascendency. Its rivals, Obesity Surgery and Bariatric Surgery are at risk. The term obesity has never been popular. It is a pejorative. It is a word that, to our lay and even some of our medical communities, carries a stigma, a problem reflecting a weakness of the person and to be solved by the person being stronger. The word bariatric is a resort to the Greek language to hide this unpleasantness.

But, more importantly, both terms are at risk because they are too narrow. They focus on obesity as the primary problem when we worry more about the diseases, the physical and psychosocial disabilities and the shortened length of life that are caused by obesity.  They focus on achieving weight loss as the primary aim when we want our patients to achieve better health, greater quality of life and a longer survival.

The term metabolic surgery has been used for more than 35 years, since Henry Buchwald and Richard Varco published their book of that name in 1978. They provided a broad definition of metabolic surgery - “the operative manipulation of a normal organ or organ system to achieve biological results for potential health gain”. It remains an appropriate definition today. Dr Buchwald went further to lock in the concept of metabolic surgery during the 1980s with a very fine series of studies of a small bowel bypass that aimed purely at the control of severe hypercholesterolemia. More recently, Francesco Rubino, Ricardo Cohen and others have investigated various gut modifications to control diabetes directly rather than through weight loss per se.

A metabolic disease may be defined as one where the processes, regulation or control of converting food to energy is abnormal. Some of the metabolic diseases are amenable to surgical treatment and thus form the basis for metabolic surgery. Obesity itself is a metabolic disease and, along with type 2 diabetes, is one of the two principal diseases that attract metabolic surgical treatments. Others include the dyslipidaemias, hypertension, the atheromatous coronary and peripheral vascular diseases, polycystic ovary syndrome, non-alcoholic steatohepatitis, obstructive sleep apnoea and number of common cancers.

The number of people in the world already suffering or at risk of metabolic disease is beyond counting. There are now more than 300 million with diabetes and three times that number with prediabetes. There are 500 million with obesity and another 1.5 billion are overweight. And there are probably 500 million with the metabolic syndrome. The metabolic diseases represent the greatest health threat we have.

Metabolic surgery can change whole body metabolism. Its effects can include improved glucose homeostasis through changes in insulin resistance or improved pancreatic β cell function, modulation of multiple gut hormones and adipokines as well as changes in immune competence, cellular energetics and inflammation. Metabolic surgery can reduce the risks of cardiovascular diseases, diabetes and cancer. And it can change weight.

Weight loss is frequently an important component but it is not always an essential element in metabolic surgery. The people of the present study had excess weight but were not obese. Nevertheless weight loss proved to be important. The extent of weight loss correlated strongly with the likelihood of remission of diabetes, regardless of the treatment group. The outcome was remarkable. More than half of the banded patients in this study were in remission of their diabetes at two years after a simple and safe day surgery procedure. It has proved to be powerful and cost-effective healthcare.

It is time for us to make a difference by recognizing what we are really trying to do and calling it correctly. It is not obesity surgery; it is not bariatric surgery; it is metabolic surgery. Recognition of the concepts, the role and outcome data of metabolic surgery should drive a dramatic growth in this clinical activity. We now have multiple high quality RCTs showing that metabolic surgery can lead to remission rates for diabetes far above anything that can be achieved by best medical practice. We have multiple RCTs showing reduction of the metabolic syndrome to close to zero. We now know we can prevent prediabetes from progressing.

By moving to metabolic surgery we move away from fighting the prejudices that obesity is the patient’s problem and that bariatric surgery is little more than a group of cosmetic procedures. We can drive the awareness of how powerful these metabolic surgical treatments could be. What else in medical practice can achieve the health benefits of metabolic surgery? Where else in medicine is there such a massive unmet need? And, as this RCT demonstrates, what other safe outpatient cost-effective option can make such a difference?

1.Wentworth J, Playfair J, Laurie C, Rithchie M, Brown W, Burton P, Shaw J O'Brien P. Multidisciplinary diabetes care with and without bariatric surgery in overweight people: A randomised controlled trial Lancet Diabetes-Endocrinology. 2014;ePub