Although multiple international medical societies over recent years have recommended lowering the threshold for bariatric surgery to a body mass index (BMI) of 30-35 (class 1 obesity) in certain patients, very few patients in this weight category have had such surgery, according to a new study.
On the basis of data from a large U.S. national registry, during 2015 through 2021,
Most surgeries (96.5%) were in patients with a BMI greater than 35. This reflects advice from a 1991 consensus statement by the National Institutes of Health stating that bariatric surgery can be offered to patients with BMI greater than or equal to 40, or greater than or equal to 35 with comorbidities.
However, medical societies have recommended lower cutoffs in position statements in 2016, 2018, and 2022.
Paul Wisniowski, MD, a surgical resident at Keck School of Medicine of University of Southern California, Los Angeles, presented the study findings in an e-poster at the annual meeting of the American Society for Metabolic & Bariatric Surgery.
“Professional guidelines and increasing data support bariatric surgery for patients beginning at BMI 30, which is a tipping point for disease progression. Now it needs to happen in the real world,” outgoing ASMBS president Teresa LaMasters, MD, who was not involved with this research, said in an ASMBS press release.
Dr. Teresa LaMasters
“We encourage greater consideration of this important treatment option earlier in the disease process,” stressed Dr. LaMasters, a bariatric surgeon and Medical Director, Unity Point Clinic Weight Loss Specialists, West Des Moines, IA.
‘Not unexpected,’ ‘need to expand eligibility’
“We expected that there had been little widespread adoption of the new BMI criteria/cutoffs,” senior study author Matthew J. Martin, MD, said in an interview.
“We know that bariatric surgery is already underutilized, as only about 1%-2% of eligible patients who would benefit end up getting surgery,” added Dr. Martin, Chief, Emergency General Surgery, and Director, Acute Care Surgery Research, USC Medical Center and Keck School of Medicine.
He suggests that the main reason that more patients with lower BMIs are not being offered surgery is related to insurance coverage and reimbursement.
“Even though the professional society guidelines have changed, based on the scientific evidence, most insurers are still using the very outdated (1990s) NIH consensus criteria of BMI greater than 35 with comorbidities, or BMI greater than 40.”
Another potential reason is “the lack of awareness of the changing guidelines and recommendation among primary care physicians who refer patients for a bariatric surgery evaluation.”
“I think it is too early in the experience with the new, more effective antiobesity medications to say which group will benefit the most or will prefer them over surgery,” he said.
“There is still only a small minority of patients who end up getting the [newer antiobesity] medications or surgery.”
“The takeaway,” Dr. Martin summarized, “is that bariatric surgery remains the only intervention with a high success rate for patients with class 1 or higher obesity in terms of weight loss, comorbidity improvement or resolution, and sustained health benefits.”
“We need to expand the availability of bariatric surgery for all eligible patients, particularly the class 1 obesity population who are currently the most underserved,” he said.
“This will take continued lobbying and working with the insurance companies to update their guidelines/criteria, education of patients, and education of primary care physicians so that patients can be appropriately referred for a surgical evaluation.”