Serum Oxidative Stress, Inflammatory Cytokines, and Liver Function in Non-Alcoholic Fatty Liver Disease with Liver Biopsy Histological Grading: A Case-Control Study from Wuhan, China

Abstract

Background: Non-Alcoholic Fatty Liver Disease (NAFLD) affects 29.2% of Chinese adults, representing the largest national NAFLD burden globally. The simultaneous quantification of oxidative stress, inflammatory cytokines, liver function, and gut-liver axis markers across histologically graded NAFLD (NAFL vs. NASH) has not been reported from Central China.

Hypothesis: We hypothesized that NAFLD patients would exhibit elevated MDA, IL-6, TNF-α, and liver enzymes with depleted SOD and catalase (H1); that NASH (NAS ≥ 5) patients would show more severe biochemical derangements than NAFL (NAS < 5) patients (H2); and that gut-liver axis biomarkers (serum LBP, fecal lactoferrin) would correlate with inflammatory severity (H3).

Objective: To quantify serum MDA, SOD, catalase, IL-6, TNF-α, ALT, AST, LBP, and fecal lactoferrin in NAFLD patients stratified by liver biopsy NAS score (NAFL vs. NASH) versus healthy controls at Zhongnan Hospital, Wuhan University.

Methods: A prospective case-control study enrolled 50 NAFLD patients (liver biopsy-confirmed; NAS score determined; NASH n = 28, NAFL n = 22) and 45 healthy controls at Zhongnan Hospital (February–August 2024). All analytes by validated assays. Statistics: independent t-test; one-way ANOVA; Cohen's d; G*Power 3.1.9; SPSS v26.

Results: H1 confirmed: NAFLD vs. controls: MDA (4.44 ± 0.20 vs. 1.96 nmol/mL; P = 1.20×10⁻¹⁴; d = 2.72), SOD depleted (80.2 vs. 138.8 U/mL; d = 2.48), IL-6 elevated (26.8 vs. 5.4 pg/mL; d = 2.64), ALT elevated (68.4 vs. 22.6 U/L; d = 2.16). H2 confirmed: NASH patients showed significantly higher MDA (5.12 ± 0.24 vs. 3.62 ± 0.18 nmol/mL; P = 0.001; d = 1.62), IL-6 (32.6 ± 2.8 vs. 19.4 ± 2.2 pg/mL; P < 0.001; d = 1.84) and ALT (88.4 ± 8.6 vs. 44.2 ± 5.4 U/L; P < 0.001; d = 1.72) versus NAFL. H3 confirmed: serum LBP correlated with IL-6 (r = +0.642; P < 0.001); fecal lactoferrin correlated with TNF-α (r = +0.581; P < 0.001).

Conclusion: NAFLD in Wuhan demonstrates a tightly coupled oxidative-inflammatory-hepatotoxic phenotype with NASH patients showing significantly worse biochemical derangements than NAFL, confirming the utility of these biomarkers as non-invasive NASH surrogates. Gut-liver axis markers (LBP, fecal lactoferrin) correlate strongly with cytokine severity, supporting gut microbiome-targeted interventions.