Frequency of hepatic steatosis and its association with the pneumonia severity score on chest computed tomography in adult COVID-19 patients

World J Crit Care Med. 2021 May 9;10(3):47-57. doi: 10.5492/wjccm.v10.i3.47.


Background: Recent studies of the coronavirus disease 2019 (COVID-19) demonstrated that obesity is significantly associated with increased disease severity, clinical outcome, and mortality. The association between hepatic steatosis, which frequently accompanies obesity, and the pneumonia severity score (PSS) evaluated on computed tomography (CT), and the prevalence of steatosis in patients with COVID-19 remains to be elucidated.

Aim: To assess the frequency of hepatic steatosis in the chest CT of COVID-19 patients and its association with the PSS.

Methods: The chest CT images of 485 patients who were admitted to the emergency department with suspected COVID-19 were retrospectively evaluated. The patients were divided into two groups as COVID-19-positive [CT- and reverse transcriptase-polymerase chain reaction (RT-PCR)-positive] and controls (CT- and RT-PCR-negative). The CT images of both groups were evaluated for PSS as the ratio of the volume of involved lung parenchyma to the total lung volume. Hepatic steatosis was defined as a liver attenuation value of ≤ 40 Hounsfield units (HU).

Results: Of the 485 patients, 56.5% (n = 274) were defined as the COVID-19-positive group and 43.5% (n = 211) as the control group. The average age of the COVID-19-positive group was significantly higher than that of the control group (50.9 ± 10.9 years vs 40.4 ± 12.3 years, P < 0.001). The frequency of hepatic steatosis in the positive group was significantly higher compared with the control group (40.9% vs 19.4%, P < 0.001). The average hepatic attenuation values were significantly lower in the positive group compared with the control group (45.7 ± 11.4 HU vs 53.9 ± 15.9 HU, P < 0.001). Logistic regression analysis showed that after adjusting for age, hypertension, diabetes mellitus, overweight, and obesity there was almost a 2.2 times greater odds of hepatic steatosis in the COVID-19-positive group than in the controls (odds ratio 2.187; 95% confidence interval: 1.336-3.580, P < 0.001).

Conclusion: The prevalence of hepatic steatosis was significantly higher in COVID-19 patients compared with controls after adjustment for age and comorbidities. This finding can be easily assessed on chest CT images.

Keywords: COVID-19; Computed tomography; Liver; Pneumonia severity score; Steatosis.