Abdominal adipose tissue distribution assessed by computed tomography and mortality in hospitalised patients with COVID-19: a retrospective longitudinal cohort study

Background Visceral adiposity has been associated with an increased risk of critical illness in COVID-19 patients. However, if it also associates to a poor survival is still not well established. The aim of the study was to assess the relationship between abdominal fat distribution and COVID-19 mortality. Methods In this six-month longitudinal cohort study, abdominal visceral (VAT) and subcutaneous adipose tissues (SAT) were measured by computed tomography in a cohort of 174 patients admitted to the emergency department with a diagnosis of COVID-19, during the first wave of pandemic. The primary exposure and outcome measures were VAT and SAT at hospital admission, and death at 30 and 180 days, respectively. Results Overall survival was not different according to VAT ( p = 0.94), SAT ( p = 0.32) and VAT/SAT ratio ( p = 0.64). However, patients in the lowest SAT quartile (thickness ≤ 11.25 mm) had a significantly reduced survival compared to those with thicker SAT (77 vs. 94% at day 30; 74 vs. 91% at day 180, p = 0.01). Similarly, a thinner SAT was associated with lower survival in Intensive Care Unit (ICU) admitted patients, independently of sex or age ( p = 0.02). The VAT/SAT ratio showed a non-linear increased risk of ICU admission, which plateaued out and tended for inversion at values greater than 1.9 ( p = 0.001), although was not associated with increased mortality rate. Conclusions: In our cohort, visceral adiposity did not increase mortality in patients with COVID-19, but low SAT may be associated with poor survival.