¹ Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
² Nutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
 

ARTICLE INFO
EDITORIAL ARTICLE		*Corresponding author hoseinzade.mahdie@gmail.com Department of Nutrition, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.   Postal code: 8915173160 Tel: +98 35 38209100-14
Article history: Received: 9 Sep 2020 Revised:1 Oct  2020 Accepted: 1 Oct  2020

 

Coronavirus disease 2019 (COVID-19) is a disease caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection that was first reported on December 31, 2019 in China (Alberca et al., 2020, Yang et al., 2020). This disease behaves variously: from asymptomatic infection to influenza-like symptoms and severe acute respiratory distress syndrome (ARDS) (Földi et al., 2020). In the recent months, COVID-19 has infected millions and killed hundreds of thousands of patients worldwide (Alberca et al., 2020). Human-to-human transmission of this disease happens mainly via direct contact or via droplets spread from an infected person’s cough or sneeze (Alberca et al., 2020). The mortality rate and severity of COVID-19 are higher in elderly people and those with diabetes, cardiovascular disease, hypertension, respiratory dysfunctions, and other underlying diseases (Alberca et al., 2020, Yang et al., 2020). In the crisis caused by COVID-19, the probability of publication of invalid data has increased. So, we tried to provide scientific evidences regarding the association between obesity and COVID-19. Furthermore, we aimed to investigate multiple mechanisms through which obesity may worsen the outcomes of COVID-19 using the published scientific literature.
Obesity is associated with chronic inflammation and metabolic disorders such as dyslipidemia, insulin resistance, and type 2 diabetes mellitus, which can affect the innate and adaptive immune responses. Consequently, it makes the immune system more vulnerable to infections and less responsive to vaccinations, antivirals, and antimicrobial medications (Dhurandhar et al., 2015).
Obesity can impair the memory CD8 T-cell responses to infections such influenza virus infection, increase the rates of mortality and viral titers in lung, and worsen the lung damage (Karlsson et al., 2010). Obesity is also related to vitamin D deficiency that can increase the risk of systemic infections and impair immune system (Bouillon et al., 2019).
The current evidence indicates that obesity is one of the main risk factors related to hospitalization, intensive care, and mortality among patients with COVID-19 (Földi et al., 2020, Kalligeros et al., 2020, Petrilli et al., 2020, Pranata et al., 2020, Yang et al., 2020). Obesity-related disorders including dysfunction of immune system, chronic inflammation, endothelium imbalance, metabolic dysfunction, and its associated comorbidities may promote pulmonary fibrosis and lead to lung functional failure, ::as char::acteristic of severe COVID-19 (Ritter et al., 2020). Furthermore, overweight and obesity can limit diaphragm movement, decrease functional lung capacity, and eventually result in hypoventilation (Dietz and Santos‐Burgoa, 2020).
Obesity may also impair motile cilia on airway epithelial cells, disrupt the function of mucociliary escalators, and decrease the clearance of severe acute respiratory syndrome coronavirus (Ritter et al., 2020). In addition, obesity is associated with chronic inflammation and impaired fibrinolysis that increases the risk of developing thrombosis and worsens lung damage (Muscogiuri et al., 2020).
Difficulty in early diagnosis by pulmonary ultrasound due to mechanical issues related to excessive weight is another important factor involved in the increased risk of severe forms of COVID-19 among the patients with obesity. This may lead to a delay in diagnosis and increased mortality rate (Muscogiuri et al., 2020). Moreover, the lack of designed medical or intensive care units for obese patients and the difficulties of intubation and insertion of catheters related to excess of weight may delay the therapeutic processes and worsen the prognosis in obese patients with COVID-19 (Muscogiuri et al., 2020). Therefore, identifying the risk factors related to morbidity and mortality of COVID-19 is important to take appropriate prevention and therapeutic measures. Individuals with overweight and obesity are among the high-
risk group related to COVID19 who should be considered more seriously. Furthermore, preventive and curative interventions are required to decrease the probability of disease development in COVID-19 cases.
Acknowledgments
The authors appreciate department of nutrition of school of public health in Shahid Sadoughi University of Medical Sciences, Yazd, Iran, to support this study.
Authors’ contribution
Hosseinzadeh M conceived the original idea and designed the scenarios. Zohreh SS collected the data and wrote the draft of manuscript. Hosseinzadeh M critically revised the manuscript and confirmed the final version of it to submit. All authors read and approved the final version of manuscript.
Conflict of interest
The authors declared that there was no conflict of interest.
 
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