The association between immunoinflammatory biomarkers NLR, PLR, LMR and nonalcoholic fatty liver disease: a systematic review and meta-analysis.

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disorder closely linked to metabolic syndrome. Identifying novel, easily measurable biomarkers could significantly enhance the diagnosis and management of NAFLD in clinical settings. Recent studies suggest that immunoinflammatory biomarkers-specifically, the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR)-may offer diagnostic value for NAFLD. However, the effectiveness of these biomarkers has not been comprehensively assessed in this patient population. This systematic review and meta-analysis aimed to evaluate the association between these immunoinflammatory biomarkers and NAFLD. As of August 8, 2024, databases including PubMed, EMBASE, Cochrane Library, Web of Science, and Scopus were systematically searched to compare NLR, PLR, and LMR levels in NAFLD patients and healthy controls. Study quality was assessed using the Newcastle-Ottawa Scale, and standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated (PROSPERO registry number: CRD42024580812). A total of 20 studies were included in the meta-analysis. Results indicated that NAFLD patients had significantly higher NLR levels (SMD = 0.43; 95% CI 0.28-0.58; p < 0.001) and lower PLR levels (SMD = - 0.29; 95% CI - 0.41 to - 0.17; p < 0.001) compared to controls. However, no significant difference in LMR was observed between NAFLD patients and controls(SMD = 0.08; 95% CI - 0.00 to 0.17; p = 0.051). These findings suggest that NLR and PLR may hold promise as diagnostic markers for NAFLD, while LMR appears to have limited diagnostic utility. Further research is warranted to explore the potential role of these biomarkers in tracking disease progression.