Weight Loss and COVID-19 Severity: Unpacking the Connection and Its Health Implications

Study Links Bariatric Surgery Weight Loss to Reduced COVID-19 Severity

Current COVID-19 Landscape

As of 2022, global COVID-19 cases have surpassed 290 million, with over five million fatalities reported. While newer variants generally exhibit lower mortality rates, specific groups continue to face heightened risks for severe infections. Key risk factors include individuals aged sixty-five and older, those with diabetes, chronic kidney disease, weakened immune systems, chronic lung disease, and obesity.

Understanding Obesity

Obesity is defined by excessive fat accumulation, indicated by a body mass index (BMI) exceeding thirty. The worldwide prevalence of obesity has nearly tripled since 1975, with childhood obesity emerging as a critical health concern. Research since the COVID-19 pandemic began has increasingly highlighted the link between obesity and severe COVID-19 infections, suggesting that systemic inflammation and immune dysfunction associated with obesity may worsen infection severity. Despite this, the effect of weight loss on COVID-19 severity remained unclear.

Research from the Cleveland Clinic

A recent study by researchers at the Cleveland Clinic sought to determine whether substantial weight loss from bariatric surgery correlates with reduced risk and severity of COVID-19. The findings were published in the journal JAMA Surgery.

The research team examined data from the Cleveland Clinic Health System, focusing on patients who had bariatric surgery—specifically gastric bypass or sleeve gastrectomy—between January 2004 and December 2017. Eligible patients had a BMI of 35 or greater, while those with certain pre-existing conditions were excluded.

To create a control group, the researchers selected three times the number of patients who did not undergo bariatric surgery but matched the surgical group in terms of age and BMI. The surgical group included 5,053 patients, while the control group comprised 15,158 patients.

Data Analysis and Pandemic Impact

The researchers conducted a statistical analysis comparing weight loss and mortality causes in both groups before and during the pandemic. They evaluated pandemic-related data, including COVID-19 infection rates, hospitalizations, need for supplemental oxygen, and severe COVID-19 cases. Severe cases were defined as those requiring intensive care unit (ICU) admission, mechanical ventilation, or resulting in death.

Prior to the pandemic, the surgical group experienced an average weight loss of 20.8 percentage points, while the control group lost only 2.3 percentage points. Once the pandemic began, both groups had similar risks of contracting COVID-19; however, the surgical group displayed significantly better outcomes across various metrics.

Improved Outcomes for Surgical Patients

The surgical group showed substantial advantages over the control group in several critical areas: they were 49% less likely to be hospitalized, 63% less likely to require supplemental oxygen, and 60% less likely to experience severe COVID-19 infections.

In a press release, study author Steven Nissen, M.D., Chief Academic Officer of the Heart, Vascular, and Thoracic Institute at the Cleveland Clinic, emphasized the study’s implications. He stated, “This study supports the reversibility of the health consequences of obesity in patients with COVID-19. It suggests that focusing on weight loss as a public health strategy can lead to improved outcomes during the COVID-19 pandemic and future outbreaks or related infectious diseases. This is particularly significant considering that 40% of Americans are affected by obesity.”

References

1. World Health Organization. WHO COVID-19 dashboard. covid19.who.int. Published 2021. Accessed January 4, 2022.
2. Affairs (ASPA) AS for P. Who is at High Risk for Serious COVID-19? combatCOVID.hhs.gov. Published February 18, 2021. Accessed January 4, 2022.
3. World Health Organization. Obesity. www.who.int. Published 2021. Accessed January 4, 2022.
4. World Health Organization. Obesity and overweight. World Health Organization. Published June 9, 2021. Accessed January 4, 2022.
5. Aminian A, Tu C, Milinovich A, Wolski KE, Kattan MW, Nissen SE. Association of Weight Loss Achieved Through Metabolic Surgery With Risk and Severity of COVID-19 Infection. JAMA Surgery. Published online December 29, 2021. doi:10.1001/jamasurg.2021.6496.