The Risks and Benefits of Bariatric Surgery

ONE OF THE questions frequently asked by patients these days pertains to the role of bariatric surgery in treatment of diabetes. On the one hand, there are claims about bariatric (or metabolic surgery) being a definitive method to cure diabetes, while on the other hand, there are critics who decry the procedure as debilitating and mutilating.

Modern bariatric surgery was initiated in 1954 with several kinds of procedures that bypassed the small intestine. The term ‘bariatrics’ was coined around 1965, from the Greek root bar (weight), suffix iatr (treatment), and suffix ic (pertaining to). Three types of surgery/procedures—gastric banding, intestinal bypass and sleeve gastrectomy—remain popular today. The rising popularity and the ensuing debate about bariatric surgery are related to the epidemic of obesity. Obesity is the mother of all modern, noncommunicable diseases—including diabetes, high blood pressure, heart disease, cancers, arthritis and others.

The key to battling the obesity epidemic lies in prevention by sustained lifestyle efforts. If obesity reaches serious proportions, it becomes a daunting task to achieve requisite weight loss with lifestyle measures alone.

The paucity of effective and safe medication for reducing weight has resulted in increasing use of surgical procedures. Bariatric surgery results in weight loss of 40-60 per cent of excess body weight, which means about 20 kg to 50 kg (or even more), depending on the degree of obesity. It improves both longevity and quality of life. According to the American Society for Metabolic and Bariatric Surgery, more than 90 per cent of people who have bariatric surgery are able to maintain a weight loss of 50 per cent or more long term.

Who should undergo bariatric surgery? Extreme obesity, with a body mass index (BMI) of 40 or more, is a clear indication. If BMI is between 35 and 40, with concomitant diseases (for example, diabetes, hypertension and other conditions where weight reduction can help), surgery should be considered. Some experts feel that the BMI cut-offs for Indians ought to be lower as we develop metabolic complications, like diabetes, at a lower body weight. The relationship between obesity and diabetes is profound and intimate. Every kilogram of weight loss results in improvement in sugar control. Weight loss per se can ameliorate diabetes to a great extent, but recent research indicates that weight loss is not the only mechanism by which bariatric surgery works. Other mechanisms, in particular those involving gut hormones, may be important. Following surgery, it has been shown that 40-90 per cent patients are diabetes-free at one year, and almost one-third can remain diabetes-free for 15 years. Bariatric surgery, therefore, can lead to ‘cure’ of diabetes in a sizeable proportion of patients. Emboldened by the success of this intervention, the use of bariatric surgery for diabetes has increased, with some experts recommending surgery at much lower BMIs. While surgery in those who are not severely obese is an exciting concept, its incorporation in universal recommendations awaits further data.

Is bariatric surgery all good news? Like most things in life, bariatric surgery has a flip side. In my experience, patients often take it to be a one-time fix. Weight loss varies a lot depending on how well you follow advice after surgery. If a person is not prepared to follow a structured diet plan and exercise, they should not venture for surgery. I advise my patients to follow a strict diet protocol for a couple of weeks before the surgery so that they are well prepared for the post-surgery period.

Like every surgery, there can be side effects of bariatric surgery too. Minor, common side effects, like nausea and constipation can be managed. Uncommon side effects include dumping syndrome (in which consuming sugar or sweets leads to nausea, vomiting and weakness), and occasionally, gall stones. If you are careless about your diet and supplements, there can be nutritional deficits too. An effect that is attracting a lot of attention of late is the change in gut bacteria, which could have both positive and negative implications.

The biggest disappointment after bariatric surgery is weight regain as time passes. While minor degrees of weight gain are common after the initial drastic weight loss, patients who do not follow guidance can, in a few years, land up almost where they started off before the surgery. Bariatric surgery is a highly effective option for managing obese patients with diabetes and may ‘cure’ diabetes for some. To benefit optimally from this advancement in medical science, it is important to keep your expectations realistic and have a firm resolve to follow lifestyle advice after surgery.

About The Author

Dr Ambrish Mithal

Dr Ambrish Mithal is Chairman, Endocrinology and Diabetes, Max Healthcare

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