Elevated Liver Enzyme (AST and ALT) as Biomarkers for Severe Dengue in Nepalese Patients: A Cross-Sectional Study

Introduction Dengue remains a major global health concern, with rising incidence and severity in endemic regions. Liver involvement, particularly elevated transaminases such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT), is frequently observed during infection. Prior research has reported inconsistent associations between AST/ALT elevation and severe dengue, particularly in diverse geographical settings. This study addresses these gaps by investigating the relationship between liver enzyme elevation and dengue severity in Nepalese patients, leveraging a pre-existing dataset to evaluate their potential as biomarkers for severe disease. Methods A cross-sectional study was conducted among 325 laboratory-confirmed dengue patients at a tertiary care hospital in Koshi province Nepal. Liver enzyme levels (AST and ALT) were categorized based on upper limit of normal (AST > 48 U/L, ALT > 55 U/L), and dengue severity was classified according to the WHO 2009 guidelines. Elevated AST & ALT were assessed for associations with DWS using Chi-square tests and multivariable logistic regression, adjusting for age and sex. Spearman’s correlations were performed to assess associations between liver enzyme elevations, clinical features, and disease severity. Variance inflation factor (VIF) was used to check for multicollinearity. Results Among the 325 dengue patients, 40.0% had dengue with warning signs (DWS). Elevated AST was significantly associated with DWS (aOR = 2.40, 95% CI: 1.49–3.86, p = 0.0003), while elevated ALT showed no significant association. AST elevation also correlated with gastrointestinal symptoms, such as nausea (ρ = 0.243, p < 0.0001) and vomiting (ρ = 0.151, p = 0.0064), and with key laboratory markers including hemoglobin (ρ = 0.407, p < 0.0001) and platelet count (ρ = 0.277, p < 0.0001). ALT showed weaker and inconsistent correlations. Adjusted analyses confirmed AST as an independent predictor of severe dengue. Female identified as a novel risk factor for DWS, independent of age and AST levels. The logistic regression model demonstrated good fit (McFadden’s R² = 0.074), with no multicollinearity detected. Conclusion This study establishes elevated AST as a significant predictor of severe dengue, offering a valuable biomarker for early risk stratification. The findings highlight the importance of liver function monitoring in dengue management. While the study's strengths include its structured assessment and comprehensive analysis, limitations such as its cross-sectional design, convenience sampling and reliance on a few centers’ dataset limit causal inference and generalizability. Future research should validate these findings in prospective, multi-center studies and assess gender-specific risks along with prognostic value of dynamic liver enzyme monitoring throughout the disease course.