Limited capacity to produce interferons contributes to progression to critical illness, says study
Obese people’s susceptibility to coronavirus is exclusive of age, sex, ethnicity, co-morbidities, as per a study by Brazilian researchers published in the journal Obesity Research and Clinical Practice.
For the study, the researchers carried out a systematic review and meta-analysis of relevant data in the scientific literature focused on nine clinical studies. This included an examination of 6,577 Covid-19 patients in five countries.
The authors noted that obesity is itself a factor that drives rapid progression to critical illnesses requiring intensive care and significantly increases the risk of death.
Lead author of the project, Silvia Sales-Peres, a professor at the University of São Paulo (USP) in Bauru, said in a statement: “Several factors contribute to the progression to critical illness in the obese organism. One is the limited capacity to produce interferons, a class of proteins secreted by defense cells and essential to inhibit viral replication and antibodies.”
He added: “In addition, adipose tissue functions as a reservoir for the virus, maintaining it in the organism for longer.”
She further said that potentially higher viral load is not the only problem with people with high body mass index (BMI).
Sales-Peres explained: “Obese patients usually (have) impaired respiratory function, as abdominal adipose tissue compresses the diaphragm and prevents it from moving normally.”
“In sum, various concurrent factors make these patients more predisposed to dependency on mechanical ventilation and other kinds of intensive care if they contract Covid-19. In the studies we analysed, 9.4 per cent of the obese patients treated in intensive care units died,” she further added.
The researchers stated that their analysis also showed the risk associated with obesity is even greater for smokers or subjects with co-morbidities such as diabetes, hypertension, and lung disease.