Coronavirus disease 2019 (COVID-19) is a highly infectious respiratory system disease that ranges from mild systemic illness to fulminant acute respiratory distress syndrome (ARDS)1. Apart from the respiratory system, COVID-19 affects the gastrointestinal (GI) tract, liver, kidneys and endocrine organs and leads to multisystemic disease2,3. In the GI system, it can involve from oral cavity till rectum4. In the early pandemic, Guan et al5 described 1099 cases of COVID-19 from Wuhan and showed that 22 per cent had deranged liver function tests (LFTs). Pan et al6 showed 20 per cent occurrence of GI symptoms which significantly increased during hospital stay. A post-mortem analysis of 25 COVID-19 patients showed that liver was found to be commonly involved after cardiorespiratory involvement7. Coronavirus (CoV) gains entry in cells by means of angiotensin-converting enzyme-2 (ACE-2) receptor8. Bangash et al9 from the United Kingdom observed that LFT derangements were common in non-severe COVID-19 cases but possibly not significant. Rarely, coronaviruses are associated with acute hepatitis or fulminant liver failure-like condition10. In a study from southern India, aspartate transaminase (AST) was deranged in 63 per cent and alanine transaminase (ALT) in 47 per cent patients on admission11. In a meta-analysis by Kulkarni et al12, the presence of deranged LFTs was associated with three-fold risk of mortality. Thus, the clinical profile and outcomes of patients with COVID-19 having deranged LFTs are sparse from our population. This study was conducted to assess the occurrence of LFT abnormalities, factors associated with it and its relation with overall outcomes such as length of hospital stay and death in patients with COVID-19 in a hospital setup.
Material & Methods
This study was a retrospective analysis of consecutive patients admitted from March 23 to October 31, 2020, with COVID-19 at a single designated COVID-19 tertiary care hospital, at department of Medical Gastroenterology Topiwala National Medical College & BYL Nair Ch. Hospital, Mumbai, Maharashtra, India. COVID-19 was confirmed by nasal or oral throat swab by reverse transcriptase–polymerase chain reaction (RT-PCR) (TaqPath™, Thermo Fisher Scientific, Pleasanton, USA). All patients were screened and categorized according to the classification criteria laid down by the Ministry of Health and Family Welfare, Government of India, into three categories13,14: (i) mild – patients with uncomplicated upper respiratory tract infection with mild symptoms and no hypoxia; (ii) moderate – pneumonia with dyspnoea, fever, tachypnoea (≥24 breaths/min) and hypoxia (SpO2 between 90 and 93%) on room air; and (iii) severe – clinical signs of pneumonia with any one of the following: (a) respiratory rate ≥30/min, and (b) oxygen saturation <90 per cent on room air. Age <18 yr, pregnant patients and cases with missing data were excluded from the study (Fig. 1). Clinical, laboratory and radiological data were obtained retrospectively from hospital records. Patients were screened for GI symptoms and abnormal LFTs (total serum bilirubin >1 mg%, AST >40 IU/l, ALT >40 IU/l, alkaline phosphatase (ALP) >310 IU/l and serum albumin <3.5 g%). Symptoms such as vomiting, diarrhoea, abdominal pain and constipation were noted and classified as GI symptoms. Liver injury was defined as total bilirubin >2 mg% and/or aspartate transaminase (AST)/alanine transaminases (ALT) >3 times upper limit of normal (ULN) and/or international normalized ratio (INR) >1.515,16. On the basis of LFTs, type of liver injury was further categorized into hepatocellular (AST and/or ALT>ULN), cholestatic (ALP>ULN) in the presence of conjugated hyperbilirubinaemia and mixed pattern (AST/ALT and ALP>ULN)17. Maximum values of LFTs during the stay were taken as peak LFTs. History of any previous liver disease and comorbidities was recorded. Significant alcohol consumption was defined as an average daily intake of >2 standard drinks (14 g alcohol) per day for >5 yr18. Viral hepatitis profile was done in clinically relevant cases. Clinical, biochemical and radiological parameters were compared at baseline on the basis of deranged LFTs at admission. The clinical impact of baseline deranged LFTs on the overall outcome, i.e. survival or death, was analyzed. Patients were grouped into non-survivors and survivors. This study was approved by the Institutional Ethics Committee (ECARP/2020/88), and the last patient was enrolled on October 31, 2020.
Chest X-ray involvement was considered present if there were unilateral or bilateral opacities or nodules not fully explained by cardiac failure or fluid overload. It included ground-glass opacity, patchy atelectasis, local patchy shadowing and diffuse alveolar abnormalities19.
Involvement on high-resolution computed tomography (HRCT) of thorax was considered when unilateral or bilateral opacities, ground-glass appearance and lobar or lung collapse were recorded. Scoring of lung involvement was given according to number of lobes involved (0-5). Each lobe was given one point in the final score19. Patients were managed on the basis of protocol laid down by the Indian Council of Medical Research (ICMR)14. Severe cases and their ventilation strategy were managed as per ICMR recommendations and acute respiratory distress syndrome (ARDS) protocol20.
Statistical analysis: Baseline characteristics of the study participants were presented. To understand the normality of data, Shapiro-Wilk test was applied. Continuous data were reported as mean (standard deviation) for normally distributed or median (Interquartile range −25th-75th percentile) for skewed distributions. Continuous data in three groups (mild, moderate, and severe liver injuries) were compared using one-way analysis of variance or Kruskal-Wallis test (for non-parametric distribution) depending on the distribution of data. Categorical variables were reported as counts (percentages). Association between categorical data was assessed by Pearson’s Chi-square test/Fisher’s exact test (when value in cell of contingency table was <5). Continuous data in survivors and non-survivors were compared using Welch t test or Mann-Whitney U test, depending on the distribution of data.
Model description: To identify the predictors of survival, variables selected were clinically relevant or those previously reported to predict COVID-19 hospitalization-related outcomes. These variables were age, sex, creatinine, AST, ALT, PaO2/FiO2 ratio, haemoglobin and neutrophil–lymphocyte ratio. The following variables were dichotomized to categorical variables for ease of interpretation. Age (<60, ≥60 yr), creatinine (<2, ≥2 mg%), haemoglobin (<12, ≥12 g%), neutrophil–lymphocyte ratio (<7.5, ≥7.5), AST (<50, ≥50 IU/l, ALT (<50, ≥50 IU/l and PaO2/FiO2 (<200, ≥200). Univariable logistic regression was done to calculate crude odds ratio (OR) for individual variables. Covariates with a P<0.30 for crude OR were selected for multivariable logistic regression. Statistical analyses were performed using R software, version 3.6.2 (R foundation, Vienna, Austria). Missing values in the patients were statistically imputed using a multiple imputation method exploiting correlations between predictor variables and between predictor variables and the survival status21.
A total of 3280 patients were screened. Seven hundred and eighty pregnant patients were excluded. Missing data were noted in 540 cases and 461 cases were <18 yr of age. Finally, 1499 patients were enrolled, of whom LFT was available in 1474 patients (Fig. 1). Data of 25 patients were adjusted through imputation during analysis. The mean age of the study population was 52.07 ±15.77 yr, of whom 969 (65%) were males. The male:female ratio was 1.91:1. Serum bilirubin levels were available in 1362 patients, serum AST and ALT levels in 1375 cases and serum ALP levels in 584 patients.
Baseline characteristics: In our study, the most common presenting symptoms were fever (75%), cough (68%) and breathlessness (57%). GI symptoms were more common in those with deranged LFTs. Patients with deranged LFTs had higher median age (54 yr vs. 51 yr, P<0.001) and male gender (72 vs. 60%, P<0.001) as compared to those with normal LFTs. Patients with deranged LFTs also had significantly lower median oxygen saturation (SpO2) on admission (90 vs. 96%, P<0.001). Deranged LFTs were also more commonly noted in those having significant alcohol consumption (P=0.001) and in smokers (P<0.001; Table I).
Diabetes mellitus (38%), hypertension (35%) and chronic kidney disease (8.6%) were the most common comorbidities. Patients with diabetes mellitus (44.8 vs. 32.1%, P<0.001) were more likely to develop deranged LFTs. Overall, 24 patients had a history of cirrhosis. These patients had deranged LFTs, but they did not suffer from severe disease significantly (Table I).
Deranged liver function tests: Overall, 681 (46.2%) cases had abnormal LFTs during the course of stay and 556 (37.68%) cases developed severe COVID-19 disease. At the time of admission, total bilirubin, AST and ALT levels were significantly higher and serum albumin was significantly lower in the deranged LFT group (P<0.001). However, acute liver injury was seen in only 7.93 per cent (n=118)) of total patients. Most of these patients, i.e. 65 (4.33%), presented with severe disease on admission, and 57 (3.5%) progressed to severe disease during hospitalization. Isolated increase in total bilirubin (>2 mg%) was the least common abnormality, noted only in 25 patients of this group. More number of patients with severe disease had deranged LFTs than with mild disease (51 vs. 29%, P<0.001; Table II). Male sex, advanced age, low SpO2 levels on admission, presence of cough, breathlessness, previous history of diabetes mellitus, chronic kidney disease (CKD), cirrhosis, history of significant alcohol consumption and smoking, high neutrophil–lymphocyte (NL) ratio, clinically severe disease and presence of chest X-ray findings were associated with deranged LFTs (Table II).
Hepatocellular type of injury was commonly seen in 93.09 per cent patients (n=1372). The most common form of liver injury seen was a change in levels 1-2 times of ULN in 60.6 per cent patients. Medical cholestatic liver disease was not seen in our study.
LFTs in different categories of COVID-19: On admission, as the severity of COVID-19 increased, liver injury also became more marked, P<0.001 (Table II). On admission, patients with severe disease showed significant changes in four of six (higher bilirubin levels, AST, ALT and lower serum albumin) LFT parameters as compared to mild disease (P<0.001). ALP was not significantly altered (Table II). The highest level of AST (5190U/l) and ALT (3020U/l) was noted in a case of ischaemic hepatitis. On assessing peak values, liver enzymes, INR, total protein and low serum albumin levels were significantly deranged in the severe category. Furthermore, hepatocellular type of injury was more significant in severe category than in mild disease (58.5 vs. 28.5%, P<0.001). More patients with liver injury on admission had clinically severe disease (7.6 vs. 2.2%, P<0.001). A similar finding was noted in patients developing liver injury during hospital stay (7.2 vs. 1.2%, P<0.001) (Table III).
Deranged LFTs and clinical outcomes: Patients with clinically severe disease were found to have higher scores of lung involvement on chest X-ray (93 vs. 16%, P<0.001) and on HRCT (2.6 vs. 0.4%, P<0.001) as compared to the mild category. However, deranged LFTs were more significantly correlated with positive chest X-ray findings (73.4 vs. 48.9%, P<0.001) only. Patients with deranged LFTs had higher need of non-invasive ventilation (14.8 vs. 6.1%, P<0.001) and mechanical ventilation (11.5 vs. 5.7%, P<0.001). Mortality was also significantly higher (27 vs. 11.1%, P<0.001) in those with deranged LFTs (Table I).
On univariate analysis, comparing survivors and non-survivors, deranged LFTs were found significant (67 vs. 42%, P<0.001). Other clinical parameters found significant were advanced age, male gender, low SpO2 levels on admission, history of diabetes mellitus, cirrhosis and tuberculosis (Table III). However, on multivariate analysis on non-survivors versus survivors, raised AST (>50 IU/l), higher age (>60 yr), serum creatinine >2 mg% and low PaO2/FiO2 (≤200) were found to be significant (Table IV). On receiver operating curve analysis (ROC) for predicting mortality, SpO2 on admission was found to be most significant (SpO2<89%, AUROC: 0.868, CI: 0.848-0.886, Sn: 83%, Sp: 78%) (Table V and Figs 2 and 3). Among LFTs, AST had AUROC 0.65 in predicting mortality (Figs. 2 and 3).
Role of drugs on deranged LFTs: After admission, deranged LFTs were also associated with drugs used in the treatment such as hydroxychloroquine (P<0.001), low-molecular-weight heparin (P<0.001) and ivermectin (P<0.001). Methylprednisolone (P<0.001), tocilizumab (P<0.001), antivirals like remdesivir (P<0.001), favipiravir (P<0.001) and lopinavir-ritonavir (Lpv/r) (P<0.001) combination were also associated with deranged LFTs (Table VI).
Outcomes in cirrhosis: Patients with cirrhosis had more deranged LFTs, irrespective of aetiology. Alcohol-related chronic liver disease was most common (14 patients). Overall, the frequency of decompensating events was more than the number of patients with cirrhosis. Ascites was the most common decompensating event. Patients with cirrhosis were more likely to suffer in-hospital mortality (3.7 vs. 1.1%) (Table III).
Median serum AST levels were more than ALT levels on admission in our patients. The most commonly deranged parameter was AST (37%) than ALT (34%); ALP was less commonly deranged (2.7%). In a meta-analysis by Kumar et al22, a lesser number of patients had elevated transaminases, but the AST levels were more than ALT levels on admission. This was consistent across all COVID-19 severity classes. It is in consonance with studies from Beijing and from the West23-25. However, this relationship changed when patients developed liver injury during hospital stay (ALT>AST). Similar findings have been previously reported24,25. Very few cases had ALP >2 times of normal (6 cases) and isolated hyperbilirubinaemia. Similar findings have been reported by Cai et al15.
In the severe category, our patients had significantly elevated levels of total bilirubin, AST, ALT, INR and low serum albumin. Furthermore, liver injury on admission was found to be significantly more in this group. These parameters were also found significant in the non-survivors. This validates the findings of Hundt et al25 who showed that peak levels of AST were at increased odds for mortality. Thus, as the severity of COVID-19 progressed, derangement of LFTs occurred and there was an increase in mortality.
Another explanation for deranged LFTs could be the use of drugs. In our study, multiple drugs were associated with deranged LFTs. as have already been reported25. In a study from China, Lpv/r fixed-dose combination was associated with deranged LFTs. Severe COVID-19 could be a confounding factor, which can explain the use of a large number of drugs found significantly associated with deranged LFTs. Moreover, severe COVID-19 patients frequently suffer from hypoxia and altered haemodynamic responses, which can lead to ischaemic changes in the liver that may lead to deranged LFTs. In a meta-analysis by Kulkarni et al12, pooled incidence of drug-induced liver injury was 25 per cent, mainly to Lpv/r combination (37%) and with remdesivir (15.2%). Bilirubin levels increase with Lpv/r combination, while remdesivir causes an increase in transaminases. Hence, the role of drugs in causing liver toxicity needs to be evaluated in a well-designed prospective study applying causality scores.
Most elevations in transaminase levels in our patients were <2 times the ULN (60%). Further, 25 per cent had elevated liver enzymes up to 2-3 times the ULN. This suggests that 85 per cent of patients had only mild derangement, as shown in studies from California and Wuhan24,26. Our study showed a progressive increase in LFT derangement (total bilirubin, AST, ALT and serum albumin) with an increase in severity. Maximum levels were seen in ischaemic hepatitis determined by the degree of shock or hypoxaemia. Acute liver failure due to COVID-19 was not seen in our study.
It was observed that patients with deranged LFT had significantly higher age than those with normal LFTs. On multivariate analysis, age was found to be significant in predicting mortality. Similar findings have been reported by others23,27,28. More males than females had deranged LFTs. However, the male gender was not significant in predicting death on multivariate analysis. A similar observation has been reported from China and the West15,24,27,28. Hundt et al25 observed that male sex was associated with mortality. Lian et al29 also reported that female sex was protective on multivariate analysis in predicting mortality. In a French study by Chaibi et al30, age and gender both were not significant in predicting mortality.
Cirrhosis was present in around 1.6 per cent of our patients, similar to a multicentre study from the USA (1.8%)31. Alcohol was the most common underlying cause. On univariate analysis, cirrhosis was associated with increased mortality. This was similar to the earlier findings which showed significantly poor outcomes among patients with cirrhosis16,17.32.
Diabetes mellitus followed by hypertension were the most common other comorbidities in our patients. Diabetes mellitus was found to be significantly associated with deranged LFTs. This was in contrast to studies, where it was not found to be significant17,24,27,31. On comparing different groups of severity, diabetes mellitus, hypertension, obstructive airway disease (OAD) and history of pulmonary or pleural tuberculosis (in past or active) were associated with more severe disease. A meta-analysis by Wang et al33 also showed that the presence of comorbidities such as OAD, diabetes, hypertension, ischaemic heart disease and cerebrovascular accidents was associated with increased risk.
On multivariate analysis comparing non-survivors and survivors, AST >50 IU/l, along with age >60 yr, low PaO2/FiO2 (≤200 IU/l) and serum creatinine >2 mg% levels were found to be significant. Raised AST (>50 IU/l) was found significant in both univariate and multivariate analyses. This observation was similar to that of Zhang et al27 and Hundt et al25.
The causes of deranged LFTs could be multi-factorial. Various aetiologies proposed are direct cytotropic effects of COVID-19, drugs, other coexisting viruses, consumption of complementary and alternative medications, pre-existing diagnosed or undiagnosed liver disease, ischaemic hepatitis, cytokine storm and probably other unknown causes. In our study, 46 per cent had deranged LFTs, while liver injury was noted in only 7.9 per cent. Similar findings have been reported from northern India, Wuhan and Shenzhen15,23,34. Liver involvement based on LFTs from 19-36 per cent has been reported in a meta-analysis35. However, in a study from Yale on 1827 cases, there were a larger number of cases with deranged LFTs, including ALP. Serum AST and total bilirubin abnormalities were seen in 83 and 23 per cent of cases during hospitalization, respectively. This study proposed a higher proportion of hospitalized patients having severe hepatitis than studies from China36. It could be due to higher average BMI, obesity and diabetes mellitus in these patients25. The primary cause of mortality in COVID-19 has been respiratory failure and cardiovascular events. Despite widespread organ involvement by the virus, liver failure as a primary pathology leading to mortality has not been recorded. However, as severity increases, derangement in LFTs increase, and are also associated with mortality.
The strength of our study was that it was carried out at a dedicated COVID-19 tertiary care hospital. The study had a large sample size, and almost all patients had LFTs on admission. Comprehensive analysis was available. However, our study had some limitations. It was a single-centre retrospective study. Hence, the presence of bias cannot be excluded. The retrospective nature of the study provided limited data on the classification of patients according to severity, admission criteria and exact treatment received. At a dedicated tertiary care referral centre for COVID-19 patients, selection bias of including more severe diseases was not ruled out. Propensity score matching was not done between groups. Organ failures were not taken into consideration. BMI was not recorded. Data on the effects of antihypertensive drugs such as angiotensin converting enzyme (ACE) inhibitors and complimentary and alternative medications were not included. Due to a lack of evidence on treatment, different classes of drugs were given, which had no clinical evidence from trials. Certain investigations such as gamma-glutamyl transpeptidase, abdominal sonography, liver fibroelastography or liver biopsy were not done. Bleeding and thrombosis events were not recorded. Only a few cases had a pre-existing liver disease, and therefore, it was difficult to evaluate the influence of liver-related comorbidities.
Our study showed that deranged LFTs were common in patients with COVID-19. It was multifactorial in origin, more common with advanced age, male gender and the presence of comorbidities such as diabetes mellitus, CKD and cirrhosis. Mild hepatocellular derangement pattern (up to 2 times ULN) was most common. Deranged ASTs, followed by ALT, were the most common abnormalities. As the level of severity increased, LFT derangement also increased. Deranged LFTs (AST >50 IU/l) are associated with in hospital mortality. More studies with short-term follow up with detailed investigations and drug profiles are required to determine the exact aetiology and outcome.
Financial support & sponsorship: None.
Conflicts of Interest: None.
1. Xu L, Liu J, Lu M, Yang D, Zheng X Liver injury during highly pathogenic human coronavirus infections. Liver Int 2020;40:998–1004.
2. Behzad S, Aghaghazvini L, Radmard AR, Gholamrezanezhad A Extrapulmonary manifestations of COVID-19
:Radiologic and clinical overview. Clin Imaging 2020;66:35–41.
3. Han H, Ma Q, Li C, Liu R, Zhao L, Wang W, et al. Profiling serum cytokines in COVID-19
patients reveals IL-6 and IL-10 are disease severity predictors. Emerg Microbes Infect 2020;9:1123–30.
4. Elhence A, Vaishnav M, Biswas S, Chauhan A, Anand A, Shalimar Coronavirus disease-2019 (COVID-19
) and the liver. J Clin Transl Hepatol 2021;9:247–55.
5. Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med 2020;382:1708–20.
6. Pan L, Mu M, Yang P, Sun Y, Wang R, Yan J, et al. Clinical characteristics of COVID-19
patients with digestive symptoms in Hubei, China:A descriptive, cross-sectional, multicenter study. Am J Gastroenterol 2020;115:766–73.
7. Li X, Wang L, Yan S, Yang F, Xiang L, Zhu J, et al. Clinical characteristics of 25 death cases with COVID-19
:A retrospective review of medical records in a single medical center, Wuhan, China. Int J Infect Dis 2020;94:128–32.
8. Han C, Duan C, Zhang S, Spiegel B, Shi H, Wang W, et al. Digestive symptoms in COVID-19
patients with mild disease severity:Clinical presentation, stool viral RNA testing, and outcomes. Am J Gastroenterol 2020;115:916–23.
9. Bangash MN, Patel J, Parekh D COVID-19
and the liver:Little cause for concern. Lancet Gastroenterol Hepatol 2020;5:529–30.
10. Jothimani D, Venugopal R, Abedin MF, Kaliamoorthy I, Rela M COVID-19
and the liver. J Hepatol 2020;73:1231–40.
11. Saithanyamurthi HV, Munirathinam M, Ananthavadivelu M Prevalence of liver injury in 445 patients with Corona Virus Disease-19-Single-centre experience from southern India. Indian J Gastroenterol 2021;40:303–8.
12. Kulkarni AV, Kumar P, Tevethia HV, Premkumar M, Arab JP, Candia R, et al. Systematic review with meta-analysis:Liver manifestations and outcomes in COVID-19
. Aliment Pharmacol Ther 2020;52:584–99.
13. Varghese GM, John R, Manesh A, Karthik R, Abraham OC Clinical management of COVID-19
. Indian J Med Res 2020;151:401–10.
14. Ministry of Health & Family Welfare, Government of India. Clinical management protocol for COVID-19 (in adults)
Available from: https://www.mohfw.gov.in/pdf/Updated DetailedClinical Management ProtocolforCOVID19adultsdated24052021.pdf
accessed on February 10, 2021.
15. Cai Q, Huang D, Yu H, Zhu Z, Xia Z, Su Y, et al. COVID-19
:Abnormal liver function tests
. J Hepatol 2020;73:566–74.
16. Sarin SK, Choudhury A, Lau GK, Zheng MH, Ji D, Abd-Elsalam S, et al. Pre-existing liver disease is associated with poor outcome in patients with SARS CoV2 infection;The APCOLIS Study (APASL COVID-19
Liver Injury Spectrum Study). Hepatol Int 2020;14:690–700.
17. Piano S, Dalbeni A, Vettore E, Benfaremo D, Mattioli M, Gambino CG, et al. Abnormal liver function tests
predict transfer to Intensive Care Unit and death in COVID-19
. Liver Int 2020;40:2394–406.
18. Schuckit MA Alcohol-use disorders. Lancet 2009;373:492–501.
19. Wasilewski PG, Mruk B, Mazur S, Półtorak-Szymczak G, Sklinda K, Walecki J COVID-19
severity scoring systems in radiological imaging –A review. Pol J Radiol 2020;85:e361–8.
20. Bein T, Grasso S, Moerer O, Quintel M, Guerin C, Deja M, et al. The standard of care of patients with ARDS:Ventilatory settings and rescue therapies for refractory hypoxemia. Intensive Care Med 2016;42:699–711.
21. Donders AR, van der Heijden GJ, Stijnen T, Moons KG Review:a gentle introduction to imputation of missing values. J Clin Epidemiol 2006;59:1087–91.
22. Kumar MP, Mishra S, Jha DK, Shukla J, Choudhury A, Mohindra R, et al. Coronavirus disease (COVID-19
) and the liver:A comprehensive systematic review and meta-analysis. Hepatol Int 2020;14:711–22.
23. Wang Q, Zhao H, Liu LG, Wang YB, Zhang T, Li MH, et al. Pattern of liver injury in adult patients with COVID-19
:A retrospective analysis of 105 patients. Mil Med Res 2020;7:28.
24. Zhang H, Liao YS, Gong J, Liu J, Zhang H Clinical characteristics and risk factors for liver injury in COVID-19
patients in Wuhan. World J Gastroenterol 2020;26:4694–702.
25. Hundt MA, Deng Y, Ciarleglio MM, Nathanson MH, Lim JK Abnormal liver tests in COVID-19
:A retrospective observational cohort study of 1,827 patients in a major U. S. Hospital Network. Hepatology 2020;72:1169–76.
26. Cholankeril G, Podboy A, Aivaliotis VI, Tarlow B, Pham EA, Spenser SP, et al. High prevalence of concurrent gastrointestinal manifestations in patients with severe acute respiratory syndrome coronavirus 2:Early experience from California. Gastroenterology 2020;159:775–7.
27. Zhang Y, Zheng L, Liu L, Zhao M, Xiao J, Zhao Q Liver impairment in COVID-19
patients:A retrospective analysis of 115 cases from a single centre in Wuhan city, China. Liver Int 2020;40:2095–103.
28. Abate BB, Kassie AM, Kassaw MW, Aragie TG, Masresha SA Sex difference in coronavirus disease (COVID-19
):A systematic review and meta-analysis. BMJ Open 2020;10:e040129.
29. Lian J, Jin X, Hao S, Jia H, Cai H, Zhang X, et al. Epidemiological, clinical, and virological characteristics of 465 hospitalized cases of coronavirus disease 2019 (COVID-19
) from Zhejiang province in China. Influenza Other Respir Viruses 2020;14:564–74.
30. Chaibi S, Boussier J, Hajj WE, Abitbol Y, Taieb S, Horaist C, et al. Liver function test abnormalities are associated with a poorer prognosis in Covid-19
patients:Results of a French cohort. Clin Res Hepatol Gastroenterol
31. Singh S, Khan A Clinical characteristics and outcomes of coronavirus disease 2019 among patients with preexisting liver disease in the United States:A Multicenter Research Network Study. Gastroenterology 2020;159:768–71 e3.
32. Shalimar, Elhence A, Vaishnav M, Kumar R, Pathak P, Soni KD, et al. Poor outcomes in patients with cirrhosis and Corona Virus Disease-19. Indian J Gastroenterol 2020;39:285–91.
33. Wang B, Li R, Lu Z, Huang Y Does comorbidity increase the risk of patients with COVID-19
:Evidence from meta-analysis. Aging (Albany NY)
34. Saini RK, Saini N, Ram S, Soni SL, Suri V, Malhotra P, et al. COVID-19
associated variations in liver function parameters:A retrospective study. Postgrad Med J 2022;98:91–7.
35. Huang C, Wang Y, Li X, Ren L, Zhao J, Hu Y, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497–506.
36. Wu Y, Li H, Guo X, Yoshida EM, Mendez-Sanchez N, Levi Sandri GB, et al. Incidence, risk factors, and prognosis of abnormal liver biochemical tests in COVID-19
patients:A systematic review and meta-analysis. Hepatol Int 2020;14:621–37.