Obesity, a known risk factor for several chronic disorders, could also elevate the risk of COVID-19 infection, a recent study revealed.
Earlier studies have shown that obesity could increase an individual's likelihood of getting severe infections from SARS-CoV-2 infection. The new research investigated how being obese, with a body mass index greater than 30 kilograms per square meter for adults and a growth curve greater than the 95th percentile for children, affected the susceptibility to COVID-19 infection.
The study was conducted among more than 72,000 participants including adults and children who visited Birmingham and Women's Hospital in the U.K., between March 2020 and January 2021.
The results suggest that obesity not only worsens the outcomes of COVID-19 but also increases the risk for infection upon exposure. "Our study identified obesity as an intrinsic risk factor for the spread of COVID-19 in individuals with comparable exposure risk," the researchers wrote in the study published in the journal PNAS Nexus.
"While the evidence has linked obesity with severe symptoms of COVID-19, the effect of obesity on susceptibility to SARS-CoV-2 infection remains unclear. Identification of intrinsic factors, which increase the likelihood of exposed individuals succumbing to productive SARS-CoV-2 infection could help plan mitigation efforts to curb the illness," the investigators wrote in the news release.
Around 33.7% of the study participants were obese, and the number aligns with the obesity prevalence in the United States, the researchers noted.
"During all waves of the pandemic, obese patients were 34% more likely to develop COVID-19 than their healthy-weight peers, regardless of age or sex, a corrected logistic regression model showed," the news release stated.
However, the researchers observed that obese patients with diabetes and hypertension had a lower risk of severe SARS-CoV-2 infection if they were older. "This variation can be associated with a compromised immune response, thereby increasing vulnerability to infections. In such contexts, the impact of obesity on susceptibility is less pronounced due to the influence of these factors," the researchers explained.
"Future mechanistic studies evaluating shared signaling pathways in obese individuals could lead to the identification of drug targets that can be used to assail the infectivity of SARS-CoV-2," they concluded.
