To the Editor Madjid et al1 recently reviewed the association between the cardiovascular system and infection with coronavirus disease 2019 (COVID-19). They point out the association between cardiovascular risk factors and the outcome of patients with COVID-19. However, the underlying risk associated with obesity was not listed among the risk factors. There are several lines of evidence that being overweight or obese is associated with risk of poor outcome (ie, admission to an intensive care unit or death) after infection with COVID-19. Recently, 72% of 775 patients with COVID-19 admitted to an intensive care unit in the UK were reported to have a body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) greater than 25 and 38% had a BMI greater than 30,2 a proportion higher than in the standard intensive care population. Obesity is also reported as a risk factor of poor outcome by the US Centers for Disease Control and Prevention.3
A potential pathophysiological background exists linking the increasing severity of COVID-19 among patients with obesity. COVID-19 binds to angiotensin-converting enzyme 2 (ACE2), a surface molecule that allow the virus to enter the host cell. In this line, the role of angiotensin-conversing enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) in the pathogenicity of COVID-19 has been intensively debated.4 The level of ACE2 expression has been reported to be high in adipose tissue, therefore likely making the adipose tissue a reservoir for severe acute respiratory syndrome coronavirus 2.5 In turn, the adipose tissue can trigger an increased inflammatory response to infection, potentially affecting all organs. Finally, patients with obesity can be at higher risk of hypoxemia due to altered thoracic compliance and the risk of lung atelectasis.
I suggest that both BMI and treatment with ACEi or ARB be systematically reported in case series of patients with COVID-19 to further appreciate their interaction and association with outcome. Further research should then explore the impact of adipose tissue on the viral load, the systemic inflammatory response, and the outcome of patients with COVID-19. In the meantime, the potential risk of future deterioration should probably be appreciated in overweight patients developing COVID-19–related symptoms.
Corresponding Author: Matthieu Legrand, MD, PhD, Department of Anesthesiology and Peri-Operative Medicine, University of California, San Francisco, 500 Parnassus Ave, San Francisco, CA 94143 (matthieu.legrand@ucsf.edu).
Published Online: November 18, 2020. doi:10.1001/jamacardio.2020.5788
Conflict of Interest Disclosures: Dr Legrand has received research support from the French Ministry of Health and SphingoTec, lecture fees from Baxter and Fresenius, and consulting fees from Novartis.