Roux-en-Y gastric bypass (RYGB) is associated with greater reduction in risk of major adverse cardiovascular events (MACE) and nephropathy in patients with type 2 diabetes mellitus (T2DM) and obesity, compared to sleeve gastrectomy (SG), according to a study led by researchers from the Cleveland Clinic, Cleveland, OH. The findings were featured in the paper, ‘Cardiovascular Outcomes in Patients With Type 2 Diabetes and Obesity: Comparison of Gastric Bypass, Sleeve Gastrectomy, and Usual Care’, published in Diabetes Care.
The primary aim of the study was to determine which one of the procedures is associated with greater reduction in risk of MACE in patients with T2DM and obesity. A total of 13,490 patients including 1,362 RYGB and 693 SG patients, and 11,435 matched nonsurgical patients with T2DM and obesity who received their care at the Cleveland Clinic (1998–2017) were analysed, with follow-up through December 2018.
With multivariable Cox regression analysis, the researchers estimated time to incident extended MACE, defined as first occurrence of coronary artery events, cerebrovascular events, heart failure, nephropathy, atrial fibrillation, and all-cause mortality.
At five years, the cumulative incidence of the primary end point was 13.7% in the RYGB group, 24.7% in the SG group (p=0.04), and 30.4% in the nonsurgical group. Of the six individual end points, RYGB was associated with a significantly lower cumulative incidence of nephropathy at five years vs SG (2.8% vs. 8.3%, p=0.005). In addition, RYGB was also associated with a greater reduction in body weight, glycated haemoglobin and use of medications to treat diabetes and cardiovascular diseases.
Compared with RYGB patients, SG patients were older (54.6 vs. 51.2 years) and had higher rates of some comorbidities at baseline including heart failure (14.3% vs. 7.7%), history of myocardial infarction (3.3% vs. 1.9%), history of atrial fibrillation (9.1% vs. 5.2%), chronic obstructive pulmonary disease (11.1% vs. 8.4%) and nephropathy (9.8% vs. 6.9%).
Patients who underwent RYGB on average had 9.7%-points greater weight and a 0.31% lower HbA1c level at five years vs SG patients. Subsequently, patients after RYGB and SG required significantly less diabetes and cardiovascular medication, vs those who received usual care.
However, five years post-RYGB, patients required more upper endoscopy (45.8% vs. 35.6%, p<0.001) and abdominal surgical procedures (10.8% vs. 5.4%, p=0.001) vs SG.
The authors concluded that both RYGB and SG were separately associated with a significant reduction in risk of MACE and all-cause mortality, compared with usual care among patients with T2DM and a BMI ≥30 kg/m2. They hypothesise that the greater and more sustained weight loss after RYGB (10% difference in total weight loss at 5 years) compared with SG, could have “meaningful physiologic effects” and “may explain better diabetes control, less medication use, and reduced risk of MACE after RYGB.”
“The findings of this large retrospective study also provide evidence suggesting that RYGB in patients with obesity and T2DM may be associated with greater weight loss, better diabetes control, and lower risk of six-component MACE and nephropathy compared with SG,” the authors cautioned. “However, given the nature of the study, these data should be considered hypothesis generating and not conclusive.”
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