Published online Sep 27, 2021. doi: 10.4254/wjh.v13.i9.1181
Peer-review started: April 20, 2021
First decision: June 17, 2021
Revised: June 25, 2021
Accepted: August 24, 2021
Article in press: August 24, 2021
Published online: September 27, 2021
Preliminary research on coronavirus disease-2019 (COVID-19) shows that the disease may have a significant impact on the gastrointestinal and hepatic systems. Namely, early research shows that liver function test (LFT) abnormalities are common, however, the incidence has ranged widely from preliminary data, from 14.8% to 78%. Furthermore, three meta-analyses have both shown that patients presenting with abnormal LFTs had a significant association with an increased risk of complication risk course [i.e. intensive care unit (ICU) admission, intubation, death], but there is currently limited single-site, large scale research on the link between LFT abnormalities and COVID outcomes.
The motivation of this research is to identify a link between LFT abnormalities and COVID-19 outcomes.
The objective of this research was to identify if there was a link between LFT elevation and outcomes in COVID-19 patients. This study did support the hypothesis that those with LFT abnormalities are at increased risk of complicated disease processes and death. Clinically, this is very important as LFT abnormalities may identify patients at risk for disease complications and may lead to early medical intervention.
Of 8028 patients infected with COVID-19 were identified and included in the study at a single academic center. Data from medical charts on laboratory testing including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (AP), and bilirubin levels, past history of liver disease, and disease course indicators including hospital admission, ICU admission, intubation, and death were recorded and analyzed. Elevated liver enzymes were defined as ALT/AST greater than 60, AP greater than 150, or bilirubin greater than 1.5, super-elevated liver enzymes were defined as ALT/AST greater than 120, AP greater than 300, or bilirubin greater than 3.0.
Of 8028 COVID-19 patients were identified and included in the study. Data from medical charts on LFTs (namely, AST, ALT, AP, and bilirubin levels), past history of liver disease, and disease course indicators (hospital/ICU admission, intubation, death) were recorded and analyzed. LFTs from 3937 patients were available for interpretation. 45% were found to have elevated or super-elevated LFT. When compared to COVID-19 patients without elevated LFTs, this cohort was found to have significantly higher odds of hospital admittance, ICU admission, intubation, and death (all P < 0.001). 248 (3.1%) had a history of liver disease. Those with elevated and super elevated LFTS had significantly higher odds of having a past history of liver disease (P < 0.001).
The findings from this study suggest that in patients who have tested positive for COVID-19, those with elevated and super elevated liver enzyme levels have significantly higher odds of hospital admittance, ICU admittance, intubation and death in comparison to those COVID-19 patients without elevated liver enzyme levels. While this research is unsure of the cause of this relationship, this research supports that LFT changes could serve as an indicator of COVID-19 outcomes and serve as a metric for evaluating those at risk for severe complications.
In research going forward, an area for improvement would be to find consistent lab values to compare and limit the possibility of missed LFT fluctuations. In addition, capturing and assessing LFTs from ambulatory patients not requiring hospitalization would increase the validity of the link between LFTs and outcomes.