Obesity and Outcomes in COVID-19: When an Epidemic and Pandemic Collide

Abstract

Obesity has reached epidemic proportions in the United States and in much of the westernized world, contributing to considerable morbidity. Several of these obesity-related morbidities are associated with greater risk for death with coronavirus disease 2019 (COVID-19). Severe acute respiratory syndrome coronavirus 2 penetrates human cells through direct binding with angiotensin-converting enzyme 2 receptors on the cell surface. Angiotensin-converting enzyme 2 expression in adipose tissue is higher than that in lung tissue, which means that adipose tissue may be vulnerable to COVID-19 infection. Obese patients also have worse outcomes with COVID-19 infection, including respiratory failure, need for mechanical ventilation, and higher mortality. Clinicians need to be more aggressive when treating obese, especially severely obese, patients with COVID-19 infection.

Figure 1

Potential obesity implications and mechanisms in coronavirus disease 2019 (COVID-19) infection. AF = atrial fibrillation = eGFR = estimated glomerular filtration rate; ERPF = effective renal plasma flow; ERV = expiratory reserve volume; FC = functional capacity; FF = filtration fraction; HDL = high-density lipoprotein; HFpEF = heart failure with preserved ejection fraction; IL-6 = interleukin 6; LDL = low-density lipoprotein; RSC = respiratory system compliance; SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2; TNF-α = tumor necrosis factor α.

Figure 2

Scheme of the effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in obese individuals. Increased production of angiotensinogen by adipose tissue leads to elevated angiotensin (Ang) II levels in obesity. SARS-CoV-2 attenuates Ang II metabolism by binding to angiotensin-converting enzyme 2 (ACE2), promoting a system imbalance. High Ang II levels lead to pulmonary vasoconstriction and inflammation that contributes to acute lung injury (left side of figure). ACE2 expression in adipose tissue is higher than that in the lung, a major target organ affected by coronavirus disease 2019 (COVID-19). Increased ACE2 expression in adipocytes may make them more vulnerable to SARS-CoV-2 infection and a potential viral reservoir leading to prolonged viral clearance (right side of the figure). AT₁R = angiotensin II type I receptor; MasR = G-protein coupled Mas receptor.