COVID-19 is the infectious disease caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2), a virus identified for the first time at the end of 2019 and which has quickly become a global pandemic.

Obesity is also considered a pandemic in our time with a prevalence, according to the WHO (World Health Organization) in 2016 of 39% of adults, having tripled in less than 50 years. As the SARS-CoV-2 pandemic became more widespread and well known, patient series were published analysing the risk factors associated with poor prognosis. Obesity is one of these factors. Patients with obesity have a higher risk of developing more severe forms of SARS-CoV-2 infection requiring respiratory support, admission to intensive care units (ICU) and also higher mortality, regardless of age. This worse prognosis can be attributed to various causes. (See section 2 of the project).

The proposed idea is to study how metabolic and immune system alterations associated with obesity may contribute to altering the response to SARS-CoV-2 infection and contribute to the higher number of complications and higher mortality in these patients. If people with obesity have a pro-inflammatory status, it is to be expected that in COVID-19 cytokine turturnover is higher in obese patients and that this explains part of the poor prognosis and complications in this group of patients.

The main objective of the study is to analyse whether in patients with SARS-CoV-2 infection the production of proinflammatory cytokines, leptin and adiponectin is different in obese patients compared to normal patients and whether these values are related to greater severity of clinical presentation and a worse prognosis.

We also want to analyse whether the different concentrations of cytokines and adipokines are related to prognosis independently of other comorbidities such as age, sex, hypertension, cardiovascular disease and diabetes.

As secondary objectives, we will look at whether the different types of lymphocytes, cells also involved in the immune response, are different in obese people compared to normal people. Finally, to see if there is a relationship between leptin levels and inflammatory cytokines and lymphopenia. Serial determinations will be carried out in order to know the evolution in its synthesis and in the progression of COVID-19.

The impact that the implementation of this project may have is at different levels:

1. Improve the knowledge of the immune response in patients with COVID-19 and to know if this response is different in obese versus normal patients.
2. Establish programmes that allow closer surveillance and monitoring of obese patients.
3. Optimise treatment and also when vaccines are available in this group of patients.