Those With Class 1 Obesity Should Be Eligible for Bariatric Surgery

Marlene Busko

June 22, 2021

Dr Maria S. Altieri

There is a need to update the current criteria for the bariatric/metabolic surgery indication to include patients with a body mass index (BMI) of 30 to 35 kg/m2 (class 1 obesity), says the lead author of a new study.

The research showed that "bariatric surgery is effective in weight loss and resolution of comorbidities" in patients with class 1 obesity who do not meet the current eligibility criteria used by most insurers, said Maria S. Altieri, MD.

Altieri and colleagues found that 25% to 60% of patients with class 1 obesity and type 2 diabetes or hypertension or hypercholesterolemia had remission of these comorbidities 3 years after bariatric surgery.

"This further supports the need to update the current indication criteria," said Altieri, who is assistant professor, bariatric and minimally invasive surgery, East Carolina University, Greenville, North Carolina.

The research was presented June 12 at the American Society of Metabolic and Bariatric Surgery (ASMBS) 2021 Annual Meeting.

Bariatric Surgery in Patients With Class 1 Obesity

Outcomes from bariatric procedures — also called metabolic surgery when this weight-loss method can lead to improvements in metabolic diseases such as type 2 diabetes — in patients with a BMI of 30-34.9 kg/m2, below the guidelines generally used by insurers, have been reported in mainly small, single-center studies.

Altieri and colleagues aimed to evaluate weight loss and resolution of the three main obesity-related comorbidities — type 2 diabetes, hypertension, and hypercholesterolemia — 3 years after bariatric surgery in patients with class 1 obesity, based on data from a large national database.

They identified 566 patients who had Roux-en-Y gastric bypass and 730 patients who had sleeve gastrectomy in 2007-2020.

Patients had a mean BMI of 33.5 kg/m2 and 82% were women. Most patients were older than age 46 and White.

Participants in both surgical groups had a similar change in BMI over time, and at 3 years had lost up to 20% of their initial BMI.

Those who were younger or female or had any of the three obesity-related comorbidities had greater weight loss.

Two years after bariatric surgery, among patients who initially had type 2 diabetes, around 45% had remission, which did not differ by surgery type.

Also at 2 years, among patients with hyperlipidemia at baseline, close to 50% of those who had Roux-en-Y gastric bypass and 25% of those who had sleeve gastrectomy had remission.

And at 3 years after surgery, among patients with hypertension at baseline, 60% of patients who had Roux-en-Y gastric bypass and 50% of patients who had sleeve gastrectomy had remission.

"The effects, risks, and benefits of bariatric surgery are the same for BMI 30-34.9 compared to BMI > 35," said Altieri.  

Should Insurance Coverage Guidelines Be Updated?

Most health insurers follow 30-year-old guidelines developed by the National Institutes of Health (NIH) in 1991, explains a statement issued by the ASMBS in conjunction with the class 1 obesity study results.

The old guidelines — issued when bariatric surgeries were open procedures whereas now they are mostly laparoscopic — state weight-loss surgery should be considered for patients with a BMI > 40 kg/m2, or "in certain instances" in those with a BMI of 35-40 kg/m2 and a serious weight-related comorbidity.

As more experience and data were gained in the decades that followed, 45 professional societies, including the ASMBS and American Diabetes Association, issued a joint statement in 2016 which recommended, among other things, that bariatric surgery "should also be considered for patients with [type 2 diabetes] and BMI 30.0–34.9 kg/m2 if hyperglycemia is inadequately controlled despite optimal treatment with either oral or injectable medications."

Similarly, in a 2018 position statement the ASMBS advised: "For patients with BMI 30-35 kg/m2 and obesity-related comorbidities who do not achieve substantial, durable weight loss and comorbidity improvement with reasonable nonsurgical methods, bariatric surgery should be offered as an option for suitable individuals."

"There are a few insurance providers that now provide coverage for metabolic surgery for patients with a BMI of 30-35 kg/m2 who have poorly controlled type 2 diabetes," Stacy Brethauer, MD, a bariatric surgeon at Ohio State University Wexner Medical Center, in Columbus, told Medscape Medical News in an email.

"However, most US payers still do not cover metabolic surgery in such patients," he noted, "despite overwhelming evidence that it alters the course of diabetes much more dramatically than medical therapy."

Dr Monique Hassan

Session comoderator Monique Hassan, MD, a bariatric surgeon at Baylor Scott & White Health, in Temple, Texas, noted in an interview with Medscape Medical News that insurance coverage of bariatric surgery in patients with this lower category of obesity is very rare in Texas.

"Most of the patients [with type 1 obesity and comorbidities] are counselled that if they want these procedures they have to pay out-of-pocket," said Altieri, adding that "this is obviously a significant barrier for patients who cannot afford such high out-of-pocket costs and creates a further increase in health disparities." 

This is a "huge problem," Hassan said.

"Obesity Is an Epidemic": Don't Use Surgery as a Last Resort

"Obesity is an epidemic," Hassan stressed. "Just because a person has a BMI below 35, they may still be clinically not healthy, with type 2 diabetes, hypertension, and sleep apnea putting them at risk for early death."

Moreover, most patients who do meet eligibility criteria for bariatric surgery don't get referred for it, she said. "Send patients," she urged clinicians.  

"The guidelines published by the ADA and ASMBS are actually pretty clear about considering surgery for patients with BMI 30-35 and poorly controlled diabetes," according to Brethauer.   

"The problem with the current paradigm," he said, "is that surgery is considered a treatment of last resort for these patients. However, the evidence is clear that the sooner you do surgery for diabetes, the better the outcomes (just like for cancer or any chronic disease)."  

"It will take a joint effort with insurance companies, physicians, and national societies in order to make a change," Altieri emphasized.

According to Brethauer, "New guidance should focus on offering surgery to treat diabetes and metabolic disease earlier in the [disease] course so that the chance of durable remission is higher."

In the meantime, bariatric surgeons "need to continue to push the payers to cover [bariatric surgery], educate referring physicians about this strong body of evidence, and continue to advocate for our patients who need treatment," he said.

Between-State Differences in Bariatric Surgery Rates

Meanwhile, another study has shown that the rate of bariatric surgery uptake, even among eligible patients, ranges from just 2% to 10% in different US states.

"Overall bariatric surgery utilization remains low and there is significant variation," lead researcher Seungjun Kim, MD, a resident at Rush University, in Chicago, Illinois, reported at the ASMBS meeting.

Using the Mariner (PearlDiver) database of commercial, Medicare, Medicaid, and other government insurance as well as self-pay claims, Kim and colleagues identified 1,789,457 patients who were eligible for bariatric surgery in 2010-2019.

Of these, 99,173 eligible patients (5.5%) underwent sleeve gastrectomy or Roux-en-Y gastric bypass, and the other 1,690,284 eligible patients did not.

Compared with eligible patients who did not have bariatric surgery, those who did were younger (mean age 44 vs 52), and more likely to be female (79% vs 66%), have commercial insurance (81% vs 70%), and live in the Northeast (31% vs 21%).

The rate of bariatric surgery among eligible patients varied from 2.1% in Vermont to 10.4% in New Jersey, and from 4.5% in the Midwest to 8.0% in the Northeast.

In Alaska, North Dakota, and Rhode Island, fewer than 30% of the surgeries were sleeve gastrectomies, whereas in New Jersey, Nevada, and Mississippi, more than 80% of the surgeries were sleeve gastrectomies.

Bariatric surgery was mostly covered by commercial insurance or Medicaid in the Northeast, and by Medicare in the Southern and Western United States.

"These state disparities in utilization, and the factors contributing to it, need to be better understood and addressed to ensure equitable access to bariatric surgery and to reduce the burden of obesity in America," senior author Scott Schimpke, MD, assistant professor, minimally invasive and bariatric surgery, Rush University, said in an ASMBS statement released with the study.

The researchers have reported no relevant financial relationships.

ASMBS 2021 Annual Meeting. Presented June 12, 2021.

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