Subcutaneous Adipose Tissue Attenuation as Marker of Prognosis in Patients Admitted with Covid-19

Research Article

Austin J Obes & Metab Synd. 2021; 5(1): 1027.

Subcutaneous Adipose Tissue Attenuation as Marker of Prognosis in Patients Admitted with Covid-19

González-Bartol E1, Sevilla T1,2*, Aparisi-Sanz A1, Aristizabal-Duque CH1, Ybarra-Falcón C1, Iglesias-Echeverría C1, Gómez-Salvador I1,2, Baladrón C1,2 and San Román A1,2

¹Department of Cardiology, Hospital Clínico Universitario de Valladolid, Ramon y Cajal 3, 47003, Valladolid, Spain

²Centro de Investigación Biomédica en Red, CIBER CV, Monforte de Lemos, 3-5, Pabellón 11, Planta 0 28029 Madrid, Spain

*Corresponding author: Teresa Sevilla, Department of Cardiology, Hospital Clínico Universitario de Valladolid, Ramon y Cajal 3, 47003, Valladolid, Spain

Received: August 20, 2021; Accepted: September 23, 2021; Published: September 30, 2021


Objective: To investigate the association of Computed Tomography (CT) Subcutaneous Adipose Tissue (SAT) attenuation with outcome in patients admitted due to SARS-CoV-2 infection.

Background: Obesity is associated with worse outcomes in coronavirus disease 2019 (COVID 19) but the underlying mechanisms are not well known. It is thought that the adipose tissue promotes a proinflammatory state that affects negatively these patients.

Methods: We retrospectively analyzed chest CT scans of 75 patients admitted for SARS-CoV-2 infection. SAT attenuation was measured. Clinical and prognostic variables were collected from the medical reports. A statistical analysis was performed to determine the association of SAT attenuation CT measurements with the prognosis of COVID 19.

Results: Mean age of patients was 71 years and 56% were male. Comorbidities included hypertension (54.7%), cancer history (27%), diabetes mellitus (25%) and obesity (8.7%). During admission 10 patients required intensive care (13.3%), all of them with mechanical ventilation and 7 patients needed vasopressor support (9.3%). In-hospital mortality occurred in 18 patients (24%). SAT attenuation was higher in hypertensive patients (-106.3±14.4 vs. -114.7±13.4 HU, p=0.011) in patients with cancer history (-102.6±13.8 vs. -112.8±13.9 HU, p=0.006 and in patients who died (-99.9 vs. -113.3 HU, p<0.001).

Conclusion: SAT attenuation was associated with death in admitted patients with COVID-19. SAT attenuation is a broadly available marker that may indicate poor prognosis in COVID-19 patients.

Keywords: Computed tomography; Subcutaneous adipose tissue; Coronavirus disease


COVID-19: Coronavirus Disease 2019; SAT: Subcutaneous Adipose Tissue; CT: Computed Tomography; HU: Hounsfield Units; BMI: Body Mass Index; IQR: Interquartile Range


The disease caused by the new coronavirus SARS-CoV2 spread rapidly in 2020 throughout the world, causing a global pandemic with high mortality [1]. More than a year later, we are still immersed in it and researchers continue working hard to identify the most vulnerable patients. Several studies have reported that obesity increases the risk of COVID-19 morbidity and mortality, especially among young adults [2-9]. However, all obese patients do not have the same response to the disease and we have to look beyond the body mass index and the amount of subcutaneous adipose tissue (SAT) if we really want to understand the mechanisms implied [10]. Chest computed tomography (CT) examination is often used to assess COVID-19 patients, however prognostic parameters beyond pulmonary affection have not been investigated yet. Besides the obvious lung evaluation, chest CT allows to quantify adipose tissue and to assess its metabolic activity. CT imaging can differentiate tissue subtypes by measuring radiodensity or attenuation with a quantitative scale, referred to as Hounsfield units (HU). In the particular case of adipose tissue, CT fat attenuation provides a non-invasive and indirect measure of fat composition and quality: Adipose tissue with relatively lower lipid content and higher vascularity has less negative (higher) Hounsfield units (HU) because the increased extracellular matrix [11]. Furthermore, CT attenuation can distinguish the metabolic activity of the adipose tissue; highly active adipose tissue will have more positive HUs, and hence greater tissue densities [12], which has been previously related to proinflammatory states.

The purpose of this study is to investigate the association of SAT attenuation with prognostic markers in patients with COVID-19 admitted to the hospital.


We retrospectively included 75 patients admitted at our hospital due to COVID-19 infection who underwent chest CT. The decision to perform the CT was made clinically, according to the responsible physician criteria. The study was performed in accordance to the institutional review board of our center.

Body mass index (BMI) was calculated as weight in kg/height in m2. Patients were considered overweighted if BMI was 25-29.9 kg/ m² and obese if BMI was ≥30kg/m². Clinical data were prospectively collected in a dedicated database during patients’ admission.

Computed Tomography analysis of adipose tissue distribution

CT images were analyzed in a dedicated Corelab (ICICORELAB) using a state-of-the-art workstation tool (AW Server, General Electric Healthcare®, Massachusetts, USA). SAT attenuation was measured in a single region of interest in the back, to avoid any interference from the mammary tissue (Figure 1).