Which patients are most likely to remain diabetes-free after weight loss surgery?

This study compared three weight-loss surgeries, gastric bypass with a 200-cm biliopancreatic limb (mRYGB), sleeve gastrectomy (SG), and greater curvature plication (GCP) in terms of sustained diabetes remission. They found that patients who had an mRYGB surgery and those with higher levels of a gut hormone called GLP-1 were most likely to remain diabetes-free after 5 years.

Obesity is an important risk factor for type 2 diabetes (T2D). Bariatric (weight-loss) surgery is an effective treatment for obese patients with T2D. There are different types of bariatric surgery, including mRYGB, SG, and GCP.  Bariatric surgery usually cures T2D in these patients temporarily, but it generally recurs after time. One of the ways that bariatric surgery helps to improve T2D is by altering gut hormones. GLP-1 is a gut hormone which increases natural insulin production. GLP-1 levels usually increase with bariatric surgery.  

Some patients will remain diabetes-free for many years after bariatric surgery but it is not clear if there is any way to predict which patients are most likely to benefit in the long-term, or which operation is best.

This study involved 45 patients with T2D and severe obesity. Patients were divided into three groups.  Group 1 had an mRYGB surgery, group 2 had an SG surgery and group 3 had a GCP surgery. Levels of gut hormones, including GLP-1, were measured before and after the surgery. Patients were followed for 5 years to monitor for recurrence of T2D.

One year after the surgery, group 1 patients had lost 35.29% of their total body weight, group 2 had lost 27.26% and group 3 had lost 20.24% of their body weight. GLP-1 levels were significantly higher one year after the surgery in group1 than in the other groups.

80% of patients in group 1 were in remission from T2D after 1 year. This was compared to 53.8% in group 2 and 20% in group 3. After 5 years, the percentage of each group that remained diabetes-free was 46.7% in group 1, 20% in group 2, and 6.6% in group 3. 

Patients who had diabetes for a shorter time before having surgery were 86% more likely to remain diabetes-free after surgery. Patients with higher levels of GLP-1 after surgery were 7 times more likely to remain diabetes-free.

This study showed that compared to the SG and GCP surgeries, the mRYGB surgery was associated with more weight loss and an increased likelihood of remaining diabetes-free at 5 years. Other factors that increased the likelihood of remaining diabetes-free were shorter duration of diabetes before surgery and increased levels of GLP-1 after surgery. 

This study involved a relatively small number of patients. Larger studies are required to confirm these findings.