Study participants
We retrospectively analyzed 206 patients with ACLF associated with chronic HBV infection who were hospitalized in the Department of Infectious Diseases at the Affiliated Hospital of Zunyi Medical University (Zunyi, China) from October 2017 to December 2020. Forty-six patients who did not undergo an oral glucose tolerance test (OGTT) on admission because they were complicated with esophageal or gastric variceal bleeding, hepatic encephalopathy or hepatorenal syndrome were excluded. Fifty-one patients were excluded for coexistence of other liver diseases: 18 had alcoholic liver disease, 13 had drug-induced hepatitis, 9 had hepatocellular carcinoma, 6 had a previous diagnosis of type 2 diabetes, and 5 were previously or presently taking steroids. Six patients who were lost to follow-up within 90 days and 7 with incomplete clinical data were also excluded. Finally, 96 patients were enrolled in the study.
Diagnostic criteria for ACLF, liver cirrhosis and bacterial infections
ACLF was diagnosed as the recent development of jaundice (total bilirubin [TBil] ≥5×upper limits of normal [ULN])and coagulopathy (prothrombin activity [PTA] <40% or international normalized ratio [INR] ≥1.5), complicated within 4 weeks by ascites and/or encephalopathy in patients with previously diagnosed or undiagnosed chronic liver disease [19].
Liver cirrhosis was diagnosed based on previous liver biopsy findings, ultrasonography, computed tomography, liver stiffness measurement or magnetic resonance imaging findings. Patients with irregular and nodular livers, small and shrunken livers, splenomegaly and hypersplenism, or evidence of portosystemic collaterals together with impaired liver synthetic function were diagnosed with liver cirrhosis [20].
Bacterial infections were diagnosed as per the following criteria [21]: (1) spontaneous bacterial peritonitis: ascitic fluid polymorphonuclear cells >250/mL or positive ascitic fluid cultures; (2) bacteremia: positive blood cultures without a source of infection; (3) pneumonia: new pulmonary infiltrate with fever (>38°C) with any respiratory symptoms (e.g., cough, sputum, dyspnea) or any findings on auscultation (rales or crepitation), or white blood cell (WBC) counts >10×109/L or <4×109/L; and (4) other bacterial infections, including skin infections, intra-abdominal infections, and infections of unknown origin.
Clinical and laboratory assessment
Patient demographics, clinical and laboratory variables, and imaging findings were collected within 24 h before and after admission.
Fasting plasma glucose (FPG), fasting insulin (FINS) and fasting C-peptide (FCP) were detected within 24 h after admission. OGTTs were performed as described by the World Health Organization with an oral anhydroglucose load of 75 g, and glycemia was measured at 0 and 2 hours. Glucose abnormalities were diagnosed based on the American Diabetes Association criteria [22]. Hypoglycemia was defined as FPG <3.8 mmol/L; diabetes was established as FPG ≥7 mmol/L or OGTT 2-h plasma glucose (OGTT 2h-PG) ≥11.1 mmol/L. IGT included patients with impaired fasting glucose (FPG of ≥5.6 mmol/L but <7 mmol/L) and/or impaired glucose tolerance (OGTT 2h-PG of ≥7.8 mmol/L and <11.1 mmol/L). Because glycated hemoglobin (HbA1c) levels may be inappropriately normal in patients with severe liver cirrhosis owing to reduced erythrocyte lifespans [2], we excluded HbA1c from this study. The homeostasis model of assessment 2-insulin resistance (HOMA2-IR), HOMA2-insulin sensitivity (HOMA2-IS), and HOMA2-β-cell function (HOMA2-β) indices were estimated with the HOMA2 calculator, version 2.2 released by the Diabetes Trials Unit at the Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford [23]. Liver disease severity was assessed using the model for end-stage liver disease (MELD) score, which was calculated using the following formula: MELD score = 3.78 × ln[TBil (mg/dL)] + 11.2 × ln[INR] + 9.57 × ln[Cr (mg/dL)] + 6.43 × (constant for liver disease etiology = 0 if cholestatic or alcoholic, otherwise = 1).
Therapeutic method and follow-up
For patients with diabetes, oral hypoglycemic agents or insulin were initiated if dietary therapy was insufficient to obtain good glycemic control. For patients with IGT, no specific treatment was administered. All patients were followed for up to 90 days after admission. In 22 patients with diabetes or IGT without oral hypoglycemic agents or insulin treatment, an OGTT was repeated to evaluate the regression of their glucose metabolism disorders. Based on their OGTT results at baseline and follow-up, patients were retrospectively assigned to one of two outcomes groups: (1) regression: from diabetes or IGT to normal glucose tolerance (NGT) or from diabetes to IGT or (2) non-regression: no change in their glucose metabolism disorders or progression from IGT or NGT to diabetes or from NGT to IGT.
Statistical analysis
SPSS, version 19.0 (IBM Corp., Armonk, NY, USA) was used for statistical processing. Differences between groups were assessed using unpaired t-tests, paired t-tests, Mann Whitney U-tests, or one-way analysis of variance (ANOVA), followed by the Bonferroni test for post hoc multiple comparisons. The chi-square test was used for categorical data. Univariate logistic regression was used to determine the risk factors associated with regression of glucose metabolism disorders. A multivariate Cox proportional hazards model was used to determine independent predictive factors of mortality. Cumulative survival was analyzed using the Kaplan-Meier method, and the curves were compared using the log-rank test. P<0.05 was considered statistically significant.