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Disclosures: Aminian reports receiving research support from Medtronic.
January 07, 2022
2 min read

Weight loss from bariatric surgery cuts COVID-19 complications risks

Disclosures: Aminian reports receiving research support from Medtronic.
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Substantial weight loss after bariatric surgery was associated with improved COVID-19 outcomes compared with nonsurgical controls, including a 49% lower risk for hospitalization and a 60% lower risk for developing severe disease, data show.

“Many studies demonstrate a strong link between obesity and clinical outcomes of COVID-19, and all available studies suggest obesity is a major risk factor for severity of COVID-19,” Ali Aminian, MD, professor of surgery and director of Cleveland Clinic’s Bariatric and Metabolic Institute, told Healio. “However, there is no study to examine whether obesity is a modifiable risk factor for COVID-19. We designed and conducted this study to assess the effects of successful weight-loss intervention on the risk for COVID-19.”

COVID-19 outcomes after bariatric surgery
Weight loss after bariatric surgery is associated with lower risks for severe COVID-19 infection, hospitalization and need for supplemental oxygen. Data were derived from Aminian A, et al. JAMA Surg. 2021;doi:10.1001/jamasurg.2021.6496.

In a retrospective, matched-cohort study, Aminian and colleagues analyzed data from 5,053 adults with a BMI of at least 35 kg/m2 who underwent Roux-en-Y gastric bypass or sleeve gastrectomy from 2004 to 2017 at Cleveland Clinic Health System (median age, 46 years; 77.6% women; median BMI, 45 kg/m2). Researchers matched patients in the surgical group 1:3 with 15,159 adults with obesity who did not undergo bariatric surgery, using electronic health record data. Researchers assessed four COVID-19-related outcomes among patients from March 2020 to March 2021: positive COVID-19 test result; hospitalization; need for supplemental oxygen; and severe COVID-19 infection, defined as a composite of ICU admission, need for mechanical ventilation or death. The overall median follow-up duration was 6.1 years.

The findings were published in JAMA Surgery.

Before the COVID-19 outbreak, patients in the surgical group lost more weight vs. controls, with a mean difference at 10 years from baseline of 18.6 percentage points (95% CI, 18.4-18.7) as well as a 53% lower 10-year cumulative incidence of all-cause, non-COVID-19 mortality vs. controls (4.7% vs. 9.4%; P < .001).

Within the cohort, 11,809 patients were available on March 1, 2020, for an assessment of COVID-19-related outcomes. The rates of positive SARS-CoV-2 test results were comparable in the surgical (9.1%) and control groups (8.7%; P = .71). However, undergoing weight-loss surgery was associated with a lower risk for hospitalization (adjusted HR = 0.51; 95% CI, 0.35-0.76), need for supplemental oxygen (aHR = 0.37; 95% CI, 0.23-0.61) and severe COVID-19 infection (aHR = 0.4; 95% CI, 0.18-0.86).

“The large magnitude of effects after losing weight with metabolic surgery was surprising,” Aminian told Healio. “If we help patients lose weight, we can reverse many health consequences of obesity. This study clearly demonstrated that obesity is a modifiable risk factor for COVID-19. Considering the worldwide prevalence of obesity, findings from this study can have significant public health implications in the current pandemic and for future infectious outbreaks.”

The researchers noted that given the observational nature of the study and the low number of infections, the findings should be considered hypothesis-generating and not conclusive.

“Let me be clear about findings of this study,” Aminian told Healio. “Anyone can develop a severe form of COVID-19; however, the risk is greater among patients with obesity. That is why everyone should follow public health recommendations, such as wearing mask and getting vaccinated. Based on our findings, in patients with obesity, losing weight can also be helpful to decrease the severity of COVID-19.”

For more information:

Ali Aminian, MD, can be reached at; Twitter: @Ali_Aminian_MD.