Conference Coverage

Bariatric surgery is most effective early in the diabetes trajectory



– In the clinical experience of Kurt GMM Alberti, DPhil, FRCP, FRCPath, bariatric surgery should be used earlier in the course of diabetes to yield the most benefit. The problem is, far fewer people with diabetes are being referred for the surgery than would benefit from it.

Dr. Kurt GMM Alberti Senior research investigator in the section of diabetes, endocrinology and metabolism at Imperial College, London, United Kingdom. Doug Brunk/MDedge News

Dr. Kurt GMM Alberti

At the World Congress on Insulin Resistance, Diabetes, and Cardiovascular Disease, Dr. Alberti said that only about 1% of eligible patients in the United States undergo bariatric surgery, compared with just 0.22% of eligible patients in the United Kingdom.

“Obesity is an increasing problem,” said Dr. Alberti, a senior research investigator in the section of diabetes, endocrinology, and metabolism at Imperial College, London. “The United States is leading the field [in obesity], and it doesn’t seem to be going away. This is in parallel with diabetes. According to the 2019 International Diabetes Federation’s Diabetes Atlas, the diabetes prevalence worldwide is now 463 million. It’s projected to reach 578 million by 2030 and 700 million by 2045. We have a major problem.”

Lifestyle modification with diet and exercise have been the cornerstone of diabetes therapy for more than 100 years, with only modest success. “A range of oral agents have been added [and they] certainly improve glycemic control, but few achieve lasting success, and few achieve remission,” Dr. Alberti said. Findings from DiRECT (Lancet. 2018;391:541-51) and the Look AHEAD (Action for Health in Diabetes) study (N Engl J Med. 2013;369:145-54) have shown dramatic improvements in glycemia, but only in the minority of patients who achieved weight loss of 10 kg or more. “In this group, 80% achieved remission after 2 years in DiRECT,” he said. “It is uncertain whether this can be sustained long term in real life, and how many people will respond. Major community prevention programs are under way in the U.S. and [United Kingdom], but many target individuals with prediabetes. Currently, it is unknown how successful these programs will be.”

The 2018 American Diabetes Association/European Association for the Study of Diabetes clinical guidelines state that bariatric surgery is a recommended treatment option for adults with type 2 diabetes and a body mass index of either 40.0 kg/m2 or higher (or 37.5 kg/m2 or higher in people of Asian ancestry) or 35.0-39.9 kg/m2 (32.5-37.4 kg/m2 in people of Asian ancestry) and who do not achieve durable weight loss and improvement in comorbidities with reasonable nonsurgical methods. According to Dr. Alberti, surgery should be an accepted option in people who have type 2 diabetes and a body mass index of 30 kg/m2 or higher, and priority should be given to adolescents, young adults, and those with a shorter duration of diabetes.

The main suggestive evidence in favor of bariatric surgery having an impact on diabetes comes from the Swedish Obese Subjects Study, which had a median follow-up of 10 years (J Intern Med. 2013;273[3]:219-34). In patients with diabetes at baseline, 30% were still in remission at 15 years after surgery. After 18 years, cumulative microvascular disease had fallen from 42 to 21 per 1,000 person-years, and macrovascular complications had fallen by 25%. “This was not a randomized, controlled trial, however,” Dr. Alberti said. Several of these studies have now been performed, including the STAMPEDE trial (N Engl J Med. 2017;376:641-51) and recent studies led by Geltrude Mingrone, MD, PhD, which show major glycemic benefit (Lancet. 2015;386[9997]:P964-73) with bariatric surgery.

According to Dr. Alberti, laparoscopic adjustable gastric lap band is the easiest bariatric surgery to perform but it has fallen out of favor because of lower diabetes remission rates, compared with the other procedures. Roux-en-Y gastric bypass, sleeve gastrectomy, and biliary pancreatic diversion are all in use. Slightly higher remission rates have been shown with biliary pancreatic diversion. “There have also been consistent improvements in quality of life and cardiovascular risk factors,” he said. “Long-term follow-up is still [needed], but, in general, it seems that diabetic complications are lower than in medically treated control groups, and mortality may also be lower. The real question is, what is the impact on complications? There we have a problem, because we do not have any good randomized, controlled trials covering a 10- to 20-year period, which would give us clear evidence. There is reasonable evidence from cohort studies, though.”

Added benefits of bariatric surgery include improved quality of life, decreased blood pressure, less sleep apnea, improved cardiovascular risk factors, and better musculoskeletal function. For now, though, an unmet need persists. “The problem is that far fewer people are referred for bariatric surgery than would benefit,” Dr. Alberti said. “There are several barriers to greater use of bariatric surgery in those with diabetes. These include physician attitudes, inadequate referrals, patient perceptions, lack of awareness among patients, inadequate insurance coverage, and particularly health system capacity. There is also a lack of sympathy for overweight people in some places.”

Dr. Alberti reported having no financial disclosures.

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