Researchers from the Heart & Vascular Institute at the Cleveland Clinic, Ohio, compared the outcomes of 2,287 obese patients with type 2 diabetes who had undergone weight loss surgery with data from 11,435 matched patients who received standard care.
A total of 75% of participants who had undergone the surgery had a body mass index (BMI) of 40 or above. The types of weight loss surgery included gastric bypass, sleeve gastrectomy, duodenal switch or adjustable gastric banding.
According to the results, those who had had surgery had a 40% lower chance of suffering major adverse cardiovascular events over a period of 8 years. These events include: all-cause mortality, coronary artery events, cerebrovascular events, heart failure, atrial fibrillation and kidney disease.
At the 8-year mark, the surgery group had lost over three times as much weight as the standard care group on average, which amounted to an extra 20 kilos. However, the surgery group also started 6 kg heavier on average. The surgery group also lowered their HbA1c by 12 mmol/mol (1.1%) more than the standard care group did.
The study did have some limitations, however. Firstly, the data were purely observational, meaning that the results can only show associations and cannot prove causality. Furthermore, the researchers acknowledged that misdiagnoses present in the database they used could introduce a certain amount of bias into the findings.
Lead researcher Dr Steven Nissen said: “Cardiovascular complications from obesity and diabetes can be devastating. 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.”
Bariatric surgeon, Dr Ali Aminian, from the Cleveland Clinic, said: “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.”
The findings of the study were presented at the European Society of Cardiology Congress, which took place in Paris last week. The research is published by the Journal of the American Medical Association (JAMA).