Visceral fat is associated to the severity of COVID-19

Abstract

Background: Excess visceral fat (VF) or high body mass index (BMI) is risk factors for severe COVID-19. The receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is expressed at higher levels in the VF than in the subcutaneous fat (SCF) of obese patients. Aim: To show that visceral fat accumulation better predicts severity of COVID-19 outcome compared to either SCF amounts or BMI. Methods: We selected patients with symptomatic COVID-19 and a computed tomography (CT) scan. Severe COVID-19 was defined as requirement for mechanical ventilation or death. Fat depots were quantified on abdominal CT scan slices and the measurements were correlated with the clinical outcomes. ACE 2 mRNA levels were quantified in fat depots of a separate group of non-COVID-19 subjects using RT-qPCR. Results: Among 165 patients with a mean BMI of 26.1 ± 5.4 kg/m 2 , VF was associated with severe COVID-19 (p = 0.022) and SCF was not (p = 0.640). Subcutaneous fat was not different in patients with mild or severe COVID-19 and the SCF/VF ratio was lower in patients with severe COVID-19 (p = 0.010). The best predictive value for severe COVID-19 was found for a VF area ≥128.5 cm 2 (ROC curve), which was independently associated with COVID-19 severity (p < 0.001). In an exploratory analysis, ACE 2 mRNA positively correlated with BMI in VF but not in SCF of non-COVID-19 patients (r 2 = 0.27 vs 0.0008). Conclusion: Severe forms of COVID-19 are associated with high visceral adiposity in European adults. On the basis of an exploratory analysis ACE 2 in the visceral fat may be a trigger for the cytokine storm, and this needs to be clarified by future studies.

COVID-19 and the pituitary

“…Obese patients are at increased risk for complicated COVID-19 and related mortality. Moreover, altered body composition with increased visceral adiposity may negatively impact prognosis in subjects with COVID-19 [ 7 , 27 ].…”

Association and Interaction Between Serum Interleukin-6 Levels and Metabolic Dysfunction-Associated Fatty Liver Disease in Patients With Severe Coronavirus Disease 2019

“…The angiotensin-converting enzyme (ACE) 2 is the receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). An exploratory analysis found that ACE 2 mRNA expression in visceral fat (VF) positively correlated with BMI, and the engagement of SARS-CoV-2 on ACE 2 in the VF would impair the enzymatic activity of ACE 2 and enhance the production of inflammatory cytokines and their release into the systemic circulation ( 13 ). Therefore, we postulated the presence of MAFLD might exacerbate the virus-induced cytokine ‘storm’ associated with COVID-19, possibly through the hepatic release of multiple pro-inflammatory cytokines.…”

Epicardial adipose tissue thickness is associated with increased COVID-19 severity and mortality

“…Other authors have shown that increased VAT deposition has a greater predictive value for adverse COVID-19 outcomes compared to BMI. This depot-specific adipose tissue dysfunction may be particularly relevant in younger cases 18–21 . These results are consistent with previous findings in this population and further contribute to the characterization of the mechanisms underlying the risk attributable to aging and obesity in severe COVID-19 25–28 .…”