Benefits of bariatric surgery examined

 In October 2007, the Foresight report, Tackling Obesities: Future Choices, predicted that if no action was taken, 60% of men and 50% of women would be obese by 2050. More recently, the report Healthy Lives, Healthy People: a call to action on obesity in England revealed that the UK is yet to see signs of a sustained decline in this worrying trend, while health inequalities relating to obesity also continue to pose a challenge. According to figures from the Department of Health,1 a total of 23% of adults are obese (with a body mass index [BMI] of over 30); while 61.3% are either overweight or obese (with a BMI of over 25). Some 23.1% of 4-5 year-olds are overweight or obese, while the figure for 10–11-year-olds is even higher at 33.3%.1 Obesity not only presents a major risk factor for diseases such as type 2 diabetes, cancer and heart disease, it also has financial implications for the NHS – excess weight is reported to cost the health service more than £5 bn each year.1 In April 2011, the first audit from the National Bariatric Surgery Registry found that bariatric surgery could be used as an alternative and cost-effective treatment to prevent a number of obesity-related health problems including type 2 diabetes.

The audit, which looked at data from 8,710 operations, found that 85.5% of people, who had type 2 diabetes prior to surgery. had seen an improvement in their condition after two years. The audit suggested that, by the time severely obese patients reach surgery, around two thirds have three or more associated diseases, while one in ten have five or more. A third will have high blood pressure; over a quarter have diabetes; nearly a fifth have high cholesterol and one sixth will suffer from sleep apnoea. As well as losing, on average, 57.8% of excess weight, improvement was recorded in all associated disease at 12 months follow-up (See Table 1). The audit concluded that long-term sufferers (some of whom have had the disease for more than ten years), take the longest to go into remission – highlighting the need to operate early on in the disease progression to obtain the best health gains for patients. The audit further highlighted the fact that obesity surgery had, so far, demonstrated a good safety record in the UK – reporting an in-hospital mortality rate of just 0.1%, which compares favourably with other forms of established surgery. More recently, the National Bariatric Surgery Registry findings were supported by research presented at the American College of Cardiology’s 61st Annual Scientific Session.2 Bariatric or ‘metabolic’ surgery was found to be more effective than intensive medical management, alone, in managing uncontrolled type 2 diabetes, for overweight or obese patients, after one year. People with uncontrolled diabetes have a much higher risk of cardiovascular complications, including heart attack, stroke and the development of secondary complications like neuropathy, retinopathy and amputation. Patients undergoing one of two stomach-reducing procedures – either laparoscopic gastric bypass or sleeve gastrectomy – in addition to medical therapy were three to four times more likely to achieve glycaemic control (a measure of diabetes control defined using HbA1c) after one year of treatment compared to those who only received intensive medical therapy.

A randomised controlled trial, STAMPEDE compared the effect of these two procedures to intensive medical therapy in helping patients achieve target goals. Although the American Diabetes Association recommends an HbA1c of less than 7%, researchers set a more aggressive (6.0%) target as a primary endpoint for the trial. This was achieved in 12.2% of the medical treatment group versus 42.0% for gastric bypass (P=0.002) and 36.7% for sleeve gastrectomy (P=0.008). In addition, people in the surgical groups had a much larger reduction in their HbA1c (2.9 vs 1.4 points), significantly greater weight loss, and reduced reliance on medications compared to those receiving medical therapy alone. “For about a century, we have been treating diabetes with pills and injections and this is one of the first studies to show that surgical therapy may, at least in some patients, be much more effective than the polypharmacy approach to treating this disease,” said Philip Schauer, the study’s lead investigator and director of the Bariatric and Metabolic Institute at the Cleveland Clinic. “It is a potential paradigm change. In patients with moderate to severe diabetes, medication therapy alone can only get them so far; they are often still well above the target of good glycaemic control.” A total of 150 patients (49±8 years, 66% female) were randomly assigned to one of three treatment groups: intensive medical therapy only, which includes a combination of counseling, lifestyle changes and medications; medical therapy plus Roux-en-Y gastric bypass; or medical therapy plus sleeve gastrectomy. Sleeve gastrectomy entails removing part of the stomach to reduce its volume by 75% to 80%; gastric bypass in the simplest terms involves two operations, the first to reduce the stomach to 2% to 3% of its usual volume (going from the size of a football to a golf ball) and the second to connect the new gastric pouch directly into the intestine to bypass the stomach. All patients had some degree of obesity (BMI of 27 to 43 kg/m2). Secondary outcomes included safety and adverse event rates, measures of glycaemic control, weight loss, co-morbidity status and cardiovascular risk profile. At 12 months, glycaemic control improved in all three groups with a mean HbA1c of 7.5% ±1.8, 6.4% ±0.9, and 6.6% ±1.0 for medical therapy, gastric bypass and sleeve gastrectomy, respectively. In general, there were no major differences in blood pressure and cholesterol control between the groups.