ASMBS 2021 Annual Meeting Select Study Highlights

Effect of Bariatric Surgery on Ischemic Stroke Risk

Key Takeaway 

• The risk of stroke is cut by more than half in what researchers believe is the largest patient sample size ever for a study on bariatric surgery and its effect on ischemic cerebrovascular disease (96,094 bariatric surgery patients and 1,533,725 matched nonsurgical patients with obesity).

The Data

• The biggest reduction in stroke risk occurred in the first year after bariatric surgery -- 0.05% vs 0.15% but was still significantly less after three (0.12% vs 0.28%) and five years (0.21% vs 0.41%).

Methodology

• Using Mariner, a national all-payer claims database, researchers identified patients with BMI > 40, or BMI > 35 with qualifying comorbidities who underwent sleeve gastrectomy or gastric bypass from 2010 to 2019. Similar patients who did not have bariatric surgery were used as controls. Coarsened exact matching in 1:1 fashion was performed, with logistic regression analysis to determine the effect of bariatric surgery on stroke risk at 1, 3, and 5 years. 

Study Authors 

• Michael Williams, Marc Sarran, Seungjun Kim, Syed Khalid, Adan Becerra, Alfonso Torquati, Philip Omotosho -- Rush University Medical Center

Outcomes in Patients Undergoing Bariatric Surgery with Class I Obesity 

Key Takeaway

• Insurers have largely restricted weight-loss surgery to people with severe obesity, but a new study finds patients with less weight to lose can achieve similar health benefits.  

The Data 

• Patients with BMIs between 30 and 35, considered Class I obesity, lost up to 20% of their initial BMIs and were 45% more likely to be in remission of their type 2 diabetes two years after either gastric bypass or sleeve gastrectomy, the two most commonly performed bariatric surgery procedures.
• Gastric bypass patients were about twice as likely to be in remission from hyperlipidemia than sleeve patients (50% vs. 25%), and the likelihood of remission of high blood pressure after three years was 60% for gastric bypass and 50% for sleeve gastrectomy. 

Methodology

• Real-world study included 566 gastric bypass patients and 730 sleeve gastrectomy patients with an average BMI of 33. Health outcomes were obtained from the Optum Clinical Electronic Health Record Database, which includes patients from different institutions throughout the United States. 

Study Authors

• Maria Altieri, William Irish, and Walter Pories, (East Carolina University Brody School of Medicine, Greenville, NC); Cody Lensing (Optum Labs at UnitedHealth Group); Suchit Mehrotra, Jejomar Derecho Bocaue, and Rossjyn Fallorina (United Health Group), Eric DeMaria (East Carolina University Brody School of Medicine) 

Variation in Bariatric Surgery Utilization by State from 2010 to 2019: Analysis of the PearlDiver Mariner Database

Key Takeaway

• Residents in states with the highest obesity rates are among the least likely to undergo weight-loss surgery, the standard of care for severe obesity and related diseases including type 2 diabetes.

The Data

• Overall utilization of bariatric surgery was highest in New Jersey (10.4%), Rhode Island (9.6%) and Delaware (9.2%) and lowest in Vermont (2.1%), Arkansas (2.6%), Alabama (2.8%) and West Virginia (2.8%) – a four to five-fold difference in utilization rates between states.
• CDC reports Midwestern (33.9%) and Southern (33.3%) states have the highest prevalence of obesity, followed by states in the Northeast (29.0%) and the West (27.4%). 
• Only about 256,000 bariatric surgeries were performed in the U.S. in 2019, which represents less than 1% of the country’s currently eligible surgical population.

Methodology

• Researchers from Rush University Medical Center in Chicago conducted a state-by-state analysis of nearly 100,000 patients who had bariatric surgery (either sleeve gastrectomy or gastric bypass) between 2010 to 2019 from a pool of 1,789,457 patients who were deemed eligible for surgery but did not get it. Patient data was obtained from the PearlDiver Mariner insurance claims database.

Study Authors

• Seungjun Kim Chicago, Adan Becerra Chicago, Marc Sarran, Michael Williams, and Scott Schimpke from Rush University Medical Center in Chicago

Effect of Bariatric Surgery on Major Cardiovascular Events: A Population Level Study

Key Takeaway

• Bariatric surgery is associated with a significant decrease in major adverse cardiovascular events (MACE) and all-cause mortality in patients with obesity and metabolic syndrome five years after surgery. 

The Data

• Bariatric surgery patients experienced significantly fewer major adverse cardiovascular events (17% vs 22%; p<0.01) and a lower rate of all-cause mortality (2.2% vs 3.9%; p<0.01) than nonsurgical patients of similar health status. Bariatric surgery was independently associated with decreased all-cause mortality (HR 0.78 [0.68-0.89]) after adjusting for age, sex and comorbidities.

Methodology

• Population-based cohort study of patients with severe obesity and metabolic syndrome (diabetes and/or hypertension) who underwent bariatric surgery (3,627) in Quebec, Canada during 2007 and 2012 and similarly matched patients who did not (5,420); incidence of MACE (myocardial infarct, stroke, all-cause mortality) and all-cause mortality at 5 years were compared; baseline demographics were comparable, but diabetes was more prevalent among the surgery group.

Study Authors

• Philippe Bouchard, Safiya Masrouri, Sebastian Demyttenaere, Olivier Court, and Amin Andalib from McGill University in Canada

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