Low visceral fat volume and hypoalbuminemia as prognostic markers in hospitalized patients with coronavirus disease 2019 during the omicron variant epidemic.

Background & Aims: The rate of severe cases of coronavirus disease 2019 (COVID-19) has decreased since the Omicron variant became epidemic. Visceral fat volume was a risk factor for COVID-19 severity with prior prevalent variants, but whether visceral fat volume remains a risk factor for the Omicron variant is unclear. We investigated the associations of clinical factors including visceral fat volume with severity and mortality among hospitalized patients with COVID-19 during the Omicron variant epidemic.

Methods: This was a single-center retrospective cohort study conducted at the Teikyo University Hospital in Japan. We included hospitalized patients with COVID-19 during the Omicron variant epidemic who underwent computed tomography of the abdomen. Clinical data were obtained from the medical records and visceral fat area (VFA) was measured using a 3-dimensional image analysis system volume analyzer. Severity was determined by the presence or absence of oxygen supplementation.

Results: Among the 226 patients, 66 patients showed moderate severity and 29 patients were non-survivors. Hypoalbuminemia was associated with severity (odds ratio [OR] 3.93, 95 % confidence interval [CI] 1.91-8.07; p = 0.0002), and hypoalbuminemia (OR 8.38, 95%CI 2.37-29.58; p = 0.0010) and low VFA (OR 3.40, 95%CI 1.15-10.06; p = 0.027) were associated with mortality. Decision tree analysis showed that mortality rate in the hypoalbuminemia and low-VFA group (37.3 %) was significantly higher than in other groups (p ≤ 0.01).

Conclusions: Low visceral fat volume and hypoalbuminemia were associated with mortality in hospitalized patients with COVID-19 during the Omicron variant epidemic. Classification by VFA and serum albumin may allow simple prediction of mortality risk among hospitalized patients with COVID-19.