IMPACT OF OBESITY ON VULNERABILITY AND SEVERITY OF SARS-COV-2 INFECTION: BIOLOGICAL RELATIONSHIP AND PREVEMNTIVE APPROACHES
Parthiba Pramanik and Purushottam Pramanik*
The current outbreak of COVID-19 around the world is a serious threat to the public health. It is a viral infection caused by severe acute respiratory syndrome coronavirus-2 (SARS Cov-2). More than 1.5 million people were died from COVID-19 due acute respiratory distress syndrome, pneumonia and multi-organs failure. Fatality rate was more in obese people than non-obese counterpart. More than 33% people of the world are obese or overweight. As COVID-19 pandemic is accelerating, this review was undertaken to evaluate the biology of impact of obesity on vulnerability and severity to SARS-CoV-2 infection. SARS Cov-2 enters in to host cells via membrane bound enzyme, angiotensin converting enzyme-2 (ACE2). This leads to imbalance of vasoprotective and vasodeletorious arms of renin angiotensin system (RAS) with over activity of vasodeletorious arms. Such imbalance of RAS induces alveolar damage, flooding the alveoli and difficulty in breathing. Obesity induces expression of ACE2 (receptor of SARS Cov-2) in lung alveolar epithelial cell membrane without increasing its catalytic activity. In consequence SARS-Cov-2 enter more easily into target cell to induce pathogenesis. Obesity augments the chance of pulmonary complication by inducing inflammation either directly or by developing insulin resistance. Accumulation of adipocytes can increase cytokine production during coronavirus infection. Cytokine storm is the main culprit of COVID-19 infection related pathogenesis. SARS-Cov-2 stores in adipose tissue and then spread to other organ to induce multi organs failure, complication of COVID-19. Vaccine is suggested to be less effective in obese/ overweight individuals. Thus weight loss for obese and overweight and prevention of obesity for non-obese and lean individuals is the best way to minimize SARS-CoV-2 infection and severity along with several other non-communicable diseases. Thus it is concluded that obesity is an emerging risk factor for susceptibility to and severity to COVID-19. It impairs the effectiveness of vaccine. Thus steps should be taken to prevent obesity among nonobese and lean individuals and weight loss among obese and overweight individuals in societies for the prevention of chronic disease and greater adverse reactions to COVID-19 pandemic.
Keywords: COVID-19, obesity, angiotensin converting enzyme, renin angiotensin system, inflammation, lipokines.
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