The latest findings from the annual Scandinavian Obesity Surgery Registry (SOReg) report could challenge existing recommendations and clinical practice for bariatric surgery and type 2 diabetes (T2DM) patients, according to the authors of a summary paper of the report, ‘Bariatric Surgery: There Is a Room for Improvement to Reduce Mortality in Patients with Type 2 Diabetes’, published in Obesity Surgery.
"SOReg provides a large high-quality database which gives the opportunity to better explore the associations between diabetes, weight loss after surgery, remission of diabetes and mortality," explained co-author of the paper, Professor Carel le Roux from the Diabetes Complications Research Center, University College Dublin, Dublin, Ireland. "Novel data which can only be obtained from these large datasets now challenge current guidelines and practice, because it appears as if we can improve significantly on our current best practice."
The 2020 SOReg report, published in May, examined 65,345 patients with up to ten-year follow-up after primary bariatric surgery and looked at the outcomes of patients with and without T2DM prior to surgery and those patients who achieved T2DM remission within one year after surgery. Crucially, the report found that the impact of T2DM duration on glycaemic remission suggest that patients with T2DM should have bariatric surgery earlier. Nevertheless, the SOReg report also shows that there was no change in the percentage of people with diabetes having bariatric surgery before 2012 (19.9%) or after 2012 (17.5%), “despite overwhelming evidence that bariatric surgery is superior to nonsurgical treatment”, the authors of the paper note.
Of the 65,345 patients included in the report, 11,990 (18.1%) patients had T2DM prior to bariatric surgery (gastric bypass or sleeve gastrectomy) and 19,281 (29.5%) had prediabetes. At 6.3 years after surgery, the report found that the mortality rate was 4.1% (487/11,990) in patients with T2DM prior to surgery, compared with 0.15% (798/53,355) in patients without T2DM prior to surgery (p<0.001).
“Thus, bariatric surgery reduces mortality compared with non-surgical medical care, but preoperative T2DM increases mortality 27-fold even after bariatric surgery. Therefore, more is needed to make bariatric surgery even better,” they write.
Moreover, in those patients with T2DM prior to surgery demonstrated improved survival if they achieved glycaemic remission one year after surgery. Some 2.9% (204/7,130) of patients died within 6.3 years despite achieving remission compared with 174 out of 3,379 patients (5.1%) who did not achieve glycaemic remission (p<0.001), meaning suboptimal glycaemic control one year after surgery was associated with a 1.7-fold increase in mortality.
They also noted that standard medications for T2DM with proven mortality benefits such as metformin, GLP-1 agonists etc are stopped after surgery - because the reduction in medication after surgery is a driver of the health economic benefit of bariatric surgery - without considering the impact on mortality. Therefore, the authors call for a “move away from the idea of surgery against medicine, but rather consider surgery with medicine.”
"We are getting better insight in what matters for the chance for remission and risk for relapse, but we could optimise this by improving collaboration between surgery and medicine," le Roux added. "Even if it seems possible to stop all drugs after surgery should we really do this? The question now is if we are keeping medications then which drug, which dose, and what metabolic targets should we aim for in the short and longer term? More work is needed, but we are on the right track."
For more information about SOReg, please click here