Weight loss surgery may have a host of beneficial effects in people with obesity.
New research presented at the European Society of Cardiology Congress, which takes place, this year, in Paris, France, suggests that bariatric, or weight loss, surgery can reduce the risk of premature mortality and cardiovascular problems more than standard medical care.
Dr. Steven Nissen, Chief Academic Officer of the Heart & Vascular Institute at the Cleveland Clinic, in Ohio, is the senior author of the study, which also appears in the Journal of the American Medical Association.
A 40% lower risk of cardiovascular events
Dr. Nissen and the team looked at data from 13,722 participants, 2,287 of whom had obesity and type 2 diabetes and had undergone weight loss surgery. The researchers compared data from this group with information from 11,435 matched controls who had only received standard medical care.
Of the 2,287 participants who underwent weight loss surgery, 75% had a body mass index (BMI) of 40 or above, which constitutes “extreme obesity.” The minimum BMI in the group was 30, which is the lower threshold for obesity.
The participants in the surgery group had each undergone one of four types of weight loss, or metabolic, procedure: gastric bypass, sleeve gastrectomy, adjustable gastric banding, or duodenal switch.
The main outcomes that the researchers looked for were death, coronary artery events, cerebrovascular events, heart failure, atrial fibrillation, and kidney disease. These are the main complications of obesity and type 2 diabetes.
The research revealed that the people who had undergone weight loss surgery had a 40% lower risk of any of these events over an 8-year follow-up period. The risk of death, specifically, was 41% lower.
Furthermore, people who had undergone metabolic surgery lost 15% more weight, on average, and had 15% lower blood sugar levels.
Dr. Ali Aminian, a bariatric surgeon at the Cleveland Clinic and the first author of the paper, comments on the findings. He says, “The striking results that we saw after metabolic surgery may be related to the patients’ substantial and sustained weight loss.”
“However, there is a growing body of evidence to suggest that there are beneficial metabolic and hormonal changes after these surgical procedures that are independent of weight loss.”
“Cardiovascular complications from obesity and diabetes can be devastating,” adds Dr. Nissen.
“Now that we’ve seen these remarkable results, a well-designed randomized controlled trial is needed to definitively determine whether metabolic surgery can reduce the incidence of major heart problems in patients with type 2 diabetes and obesity.”
Dr. Steven Nissen
The authors acknowledge that there were some limitations to their study. First, its observational nature cannot prove causality.
Secondly, misdiagnoses in the Cleveland Clinic’s electronic health records — the database from which the researchers took their information — may have biased the results.
Thirdly, “To assess status of diabetes and cardiovascular medications in follow-up, the study assessed prescription orders for medications, which does not necessarily equate to actual medication use,” write the researchers.
Furthermore, the authors did not compare the results of the different types of weight loss surgery, and fewer than 10% of the participants in the control group had taken drugs that have significant cardiovascular benefits.
However, the sensitivity of the analyses that the researchers carried out guarantee the robustness of the findings, reassure the authors.