STOCKHOLM — Bariatric surgery must expand to larger numbers of severely obese patients with complicated disease, but be cautious in patients with a body mass index below 35 kg/m
Bariatric surgery “should be the standard of care for patients with complex, morbid obesity, patients with a body mass index of 40 kg/m
In most of the world, less than 1% of patients undergo bariatric surgery even when they meet current standards for performing surgery: a BMI of at least 40 or at least 35 plus comorbidity. In Australia and in the United States, use of bariatric surgery in these patients doesn't crack 2% of the target population, even though bariatric surgery is now recognized as very effective and safe, he said. Patients with BMIs of more than 45 are “where lives are saved, people we can help now,” Dr. Dixon said.
Although Dr. Dixon has run studies that helped pioneer use of gastric banding in patients with BMIs of 30–35, he agrees with the statement earlier this year by the American Diabetes Association, which said there is “currently insufficient evidence to generally recommend surgery in patients with BMI of less than 35 kg/m
“We need better quality evidence before lowering the threshold for bariatric-metabolic surgery for lower BMI. We will need properly conducted randomized controlled trials, and benefits are likely to be less substantial than in the severely obese” patients, he said.
Dr. Dixon and his associates published results from a study that randomized 80 patients with BMIs of 30–35 and no comorbidities to gastric banding or a very low-calorie diet, pharmacotherapy, and lifestyle change. After 2 years of follow-up, the surgery patients showed significantly better weight loss, resolution of metabolic syndrome, and quality of life (Ann. Intern. Med. 2006;144:625–33).
A second study reported 2 years later ran a similar design in 60 obese patients with type 2 diabetes and a BMI between 30 and 40. Gastric banding led to a 73% remission rate of type 2 diabetes during 2-year follow-up compared with a 13% rate in controls managed by lifestyle changes only (JAMA 2008;299:316–23).
Outcomes like these have led to modest uptake of bariatric surgery in patients with BMIs less than 35, although generally no lower than a BMI of 33, Dr. Dixon said.
“What we see in Australia is that patients who are approaching a BMI of 35 and have trouble controlling their weight and have type 2 diabetes are receiving surgery, about 95% by gastric banding,” he said in an interview. Some Australian surgeons are clearing interested patients for the procedure if they have a current BMI of 33 or 34. But surgery cases with a BMI as low as 31 or 32 kg/m
A concern at lower BMI is that the risk-benefit balance in favor of surgery shifts and makes surgery a somewhat less attractive option. “At a BMI of 31 kg/m
Patients with BMIs of more than 45 are 'where lives are saved, people we can help now.'
Source DR. DIXON
Disclosures: Dr. Dixon has served on speakers bureaus of, been a consultant to, or received research support from Abbott, Bariatric Advantage, Eli Lilly, Merck, Nestlé Australia, Allergan, Scientific Intake, SP Health, and ResMed.