Cleveland Clinic: 5-Year Data Show Glycemic Benefits Last After Bariatric Surgery

Final results from a well-publicized trial at the Cleveland Clinic show that most patients who had bariatric surgery for type 2 diabetes with mild or moderate obesity sustained blood glucose and weight loss benefits for 5 years.

Findings were announced late Monday at the close of the 65^th Scientific Session of the American College of Cardiology (ACC), which concluded in Chicago, Illinois.¹

The trial, known as STAMPEDE, was featured in a late-breaking session 2 years ago at ACC, when Cleveland Clinic researchers reported that long-term diabetic patients who received bariatric surgery were able to sustain drops in glycated hemoglobin (A1C) over a 3-year period. These patients had average A1C levels of 9.2% when the study began.²

The study was among the first to suggest that reversing diabetes might not be merely a pleasant side effect of treatment for obesity, but perhaps should be considered a reason for surgery in the first place. STAMPEDE reported positive A1C outcomes for patients with body mass index (BMI) levels as low as 27 kg/m²; these patients are below the CDC-defined obesity standard of a BMI of 30 kg/m2, and thus might not be considered surgical candidates of obesity was the only criterion used.

“Some advantages of gastric bypass over sleeve gastrectomy have emerged during follow-up,” said Philip Schauer, MD, the study’s lead author. “At 5 years, gastric bypass maintained greater weight loss than sleeve gastrectomy while requiring fewer medications.”

“Most clinical guidelines and insurance policies for bariatric surgery limit access to patients with a BMI of 35 or above,” Schauer said. “Our 5-year results demonstrate that glycemic improvement in patients with a BMI of 27 to 34 is durable at least up to 5 years.”

Since STAMPEDE, studies around the world have reached similar conclusions, including one from University of Washington researchers published last month in the European journal Diabetologia.³

The Cleveland Clinic team reported the following:

· After 5 years, more than 88% of both gastric bypass and sleeve gastrectomy patients had acceptable blood glucose levels without insulin. Use of other cardiovascular and antidiabetic medications remained significantly reduced in both surgical groups.

· Larger shares of surgery patients achieved and maintained normal A1C levels (6.0% or less) over 5 years than did patients who took medication for diabetes; 29% of those with gastric bypass and 23% of those with sleeve gastrectomy, compared with 5% who took medication.

· Those who had surgery—by either method—sustained weight loss more than patients who controlled diabetes with medication, and the weight loss was the primary reason their blood glucose remained in control.

· Researchers noted, however, that the effects of surgery on blood glucose levels did diminish over time, and some late complications from surgery did emerge.

References

1. Schauer PR, Bhatt D, Kirwan J, et al. Bariatric surgery vs. intensive medical therapy for long-term glycemic control and complications of diabetes: final 5-year STAMPEDE trial results. Presented at the 65^th Scientific Session of the American College of Cardiology, Chicago, Illinois. April 4, 2016. Abstract no. 416-12.

2. Schauer PR, Bhatt DL, Kirwan JP, et al. Bariatric surgery vs. intensive medical therapy for diabetes: 3-year outcomes. N Engl J Med. 2014;370(21):2002-2013. doi: 10.1056/NEJMoa1401329

3. Cummings DE, Arterburn DE, Westbrook EO, et al. Gastric bypass surgery vs intensive lifestyle and medical intervention for type 2 diabetes: the CROSSROADS randomized controlled trial [published online March 17, 2016]. Diabetologia. 2016; 10.1007/s00125-016-3903-x.