Real-world glycemia improvements persist longer with bypass than gastrectomy
medwireNews: Roux-en-Y gastric bypass (RYGB) produces longer-lasting improvements in glycemic control than sleeve gastrectomy, despite similar initial rates of type 2 diabetes remission, shows a large real-world study.
In particular, Kathleen McTigue (University of Pittsburgh, Pennsylvania, USA) and co-researchers found that RYGB delivered better results than sleeve gastrectomy for patients who had a relatively low presurgical likelihood of achieving diabetes remission.
The team judged patients’ probability of remission by their DiaRem score, which is based on age, glycated hemoglobin (HbA1c) level, and use of insulin and oral diabetes medications. People whose scores indicated a 23–99% likelihood of remission were just as likely to achieve it with RYGB as with sleeve gastrectomy.
But at lower probabilities, patients did better with RYGB; specifically, those whose DiaRem scores indicated an 11–33% probability were a significant 1.2-fold more likely to achieve remission with RYGB than with gastrectomy. The 5-year remission rates in this subgroup were 83.4% with RYGB versus 76.6% with sleeve gastrectomy.
“Estimating the likelihood of [type 2 diabetes] remission could help inform patients’ and clinicians’ discussions of procedure choice,” write McTigue and team in JAMA Surgery.
But they add: “Informed decision-making for procedure choice should also consider other factors, such as the potential for adverse events.”
The overall cohort included 9710 adults with type 2 diabetes, of whom 64.2% underwent RYGB and 35.8% had sleeve gastrectomy. Their average preoperative BMI was 49.0 kg/m2, HbA1c was 7.2% (55 mmol/mol), and they were taking an average of 1.66 antidiabetes medications, with 48.3% using insulin.
The majority of patients achieved diabetes remission, with most remissions occurring within the first 2 years after the procedure; by year 5 the estimated cumulative remission rates were 86.1% for those who had RYGB and 83.5% for those who underwent gastrectomy.
The 5-year relapse rates, however, were markedly lower with RYGB than sleeve gastrectomy, at 33.1% versus 41.6%, equating to a significant 25% risk reduction after accounting for multiple potential confounders.
In addition to this, RYGB resulted in more weight loss during the first year after the procedure, at 29.1% versus 22.8% with gastrectomy, and this difference persisted at 5 years, with a 10.2 kg difference favoring RYGB. Reductions in HbA1c were also persistently larger with RYGB than sleeve gastrectomy, being 0.80 versus 0.35 percentage points below baseline at 5 years.
The researchers note that some recent randomized trials have demonstrated equivalent outcomes for the two approaches, but argue that their study is much larger than these trials and that their findings also reflect real-world situations.
“Thus, while the more rigorous, randomized clinical trial data indicate that RYGB and [sleeve gastrectomy] perform similarly in highly controlled environments, in everyday practice, the outcome differences may be larger,” they conclude.
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