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

Area of Science:

• Medical imaging
• Adipose tissue biology
• Infectious disease research

Background:

• Adipose tissue characteristics like radiodensity and metabolic activity may impact COVID-19 patient outcomes.
• Previous research suggests a link between body composition and infectious disease severity.

Purpose of the Study:

• To investigate the association between adipose tissue radiodensity and metabolic activity with clinical outcomes in hospitalized COVID-19 patients.
• To determine if adipose tissue characteristics can serve as a prognostic biomarker for COVID-19.

Main Methods:

• Retrospective analysis of two COVID-19 patient cohorts.
• Computed tomography (CT) used to assess subcutaneous adipose tissue radiodensity (SATR) and visceral adipose tissue radiodensity.
• FDG-PET/CT utilized to measure adipose tissue metabolic activity.
• Regression analyses examined associations with mortality, hospitalization duration, ventilation needs, and complications.

Main Results:

• Higher SATR was independently associated with increased mortality risk (OR: 2.70; P = 0.033).
• Elevated SATR correlated with longer hospital stays (P < 0.001), increased need for mechanical ventilation (P = 0.007), and higher rates of complications including acute kidney injury, secondary infection, shock, and pulmonary embolism.
• SATR showed a positive correlation with subcutaneous adipose tissue glucose uptake (ρ = 0.52) and a negative correlation with leptin levels (ρ = -0.48).

Conclusions:

• Elevated SATR at the time of COVID-19 diagnosis is a significant predictor of disease severity and adverse outcomes.
• SATR emerges as a potential prognostic biomarker for both acute and chronic inflammatory conditions, including COVID-19.