BACKGROUND AND PURPOSE:

• Obesity is a risk factor for severe COVID-19 infection, but whether losing weight is associated with improved infection outcomes is unknown
• Aminian et al. (JAMA Surg, 2021) investigated the association between a successful weight loss intervention following bariatric surgery and improved risk and severity of COVID-19 infection in patients with obesity

METHODS:

• Retrospective, observational, matched-cohort study
  • Conducted at the Cleveland Clinic Health System
• Population
  • Adult patients with a BMI ≥35 
  • Surgical group: Underwent weight loss surgery between January 2004 and December 2017
    • Roux-en-Y gastric bypass and sleeve gastrectomy
  • Control group: no surgical intervention for obesity
• Exposures
  • SARS-CoV-2 infection
• Study design
  • Outcomes were examined before and after COVID-19 outbreak on March 1, 2020
• Primary outcomes
  • Positive SARS-CoV-2 test result
  • Hospitalization
  • Need for supplemental oxygen
  • Severe COVID-19 infection composite: ICU admission | Need for mechanical ventilation | Death

RESULTS:

• 20,212 patients: 5053 underwent surgery | 15,159 control participants
  • Median (IQR) age: 46 (35 to 57) years
  • Median (IQR) BMI: 45 (41 to 51)
  • Median (IQR) follow-up duration: 6.1 (3.8 to 9.0) years
  • 77.6% female

Before the COVID-19 Outbreak

• Patients in the surgical group
  • Lost more weight than the control group; P<0.001
    • Mean difference 10 years from baseline: 18.6 (95% CI, 18.4 to 18.7) percentage points
  • Had a 53% lower 10-year cumulative incidence of all-cause non–COVID-19 mortality; P<0.001
    • Surgical: 4.7% (95% CI, 3.7 to 5.7)
    • Control: 9.4% (95% CI, 8.7 to 10.1)

Following COVID-19 Outbreak

• 11,809 patients had an assessment of COVID-19-related outcomes
• Rates of positive SARS-CoV-2 test results were comparable in the surgical and control groups; P=0.71
  • Surgical: 9.1% (95% Ci, 7.9 to 10.3)
  • Control: 8.7% (95% CI, 8.0 to 9.3)
• Undergoing weight loss surgery was associated with a lower risk of
  • Hospitalization
    • Adjusted hazard ratio (aHR) 0.51 (95% CI, 0.35 to 0.76); P<0.001
  • Need for supplemental oxygen
    • aHR 0.37 (95% CI, 0.23 to 0.61); P<0.001
  • Severe COVID-19 infection
    • aHR 0.40 (95% CI, 0.18 to 0.86); P=0.02

CONCLUSION:

• For patients with obesity, weight loss through surgery was associated with better COVID-19 outcomes, compared to people with obesity who did not undergo surgical intervention
• The authors state

Among patients with obesity, substantial weight loss achieved with surgery, compared with no surgery, was associated with a significantly lower risk of hospitalization, need for supplemental oxygen, and severe disease after contracting COVID-19 infection

The findings of this study suggest that obesity can be a modifiable risk factor for the severity of COVID-19 infection

Learn More – Primary Sources:

Association of Weight Loss Achieved Through Metabolic Surgery With Risk and Severity of COVID-19 Infection

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What are the Strongest Predictors of COVID-19 Hospitalization and Critical Illness?

Is Obesity an Independent Risk Factor for COVID-19 Related Mortality?

Pregnant Women with COVID-19 in France: Clinical Outcomes and Risk Factors for Severe Disease