Subcutaneous adipose tissue radiodensity: An emerging risk factor for severe COVID-19

Abstract

Background: Adipose tissue radiodensity and metabolic activity may influence COVID-19 outcomes. This study evaluated the association between adipose tissue characteristics and clinical outcomes in COVID-19 patients.

Methods: Two retrospective cohorts of hospitalized COVID-19 patients were analyzed. Subcutaneous adipose tissue radiodensity (SATR) and visceral adipose tissue radiodensity were assessed by computed tomography. Fluorine-18-labelled fluorodeoxyglucose PET/computed tomography measured adipose tissue metabolic activity. Associations with mortality, length of stay, ventilation requirement, and complications were examined using regression analyses.

Results: High SATR was independently associated with increased mortality risk (OR: 2.70; P = 0.033), longer hospitalization (P < 0.001), higher rates of mechanical ventilation (P = 0.007), and complications: acute kidney injury (P = 0.001), secondary infection (P = 0.007), shock (P = 0.010), and pulmonary embolism (P = 0.011). SATR positively correlated with SAT glucose uptake (ρ = 0.52) and negatively with leptin levels (ρ = -0.48).

Conclusions: Elevated SATR at COVID-19 diagnosis predicts disease severity and worse outcomes. SATR is a potential prognostic biomarker for acute and chronic inflammatory conditions.

Keywords: Body composition; Computed tomography; Inflammation; PET-CT; Survival.