The HALP Index as a Bridge Between Nutrition, Inflammation, and Coagulation in Predicting DVT Risk in Stroke Patients

The hemoglobin-albumin-lymphocyte-platelet (HALP) index, a composite marker reflecting nutritional, inflammatory, and immune status, has been linked to various health outcomes. However, its role in predicting deep vein thrombosis (DVT) occurrence in stroke patients and its potential influence on coagulation biomarkers, particularly D-dimer, remain poorly understood. This study aims to investigate the association between the HALP index and the occurrence of DVT in stroke patients, exploring the potential moderating role of HALP in regulating D-dimer levels and DVT formation. A retrospective study was conducted with 611 stroke patients, categorized into quartiles based on HALP scores. Multivariate logistic regression, restricted cubic spline (RCS) analysis, and subgroup analyses stratified by age, gender, body mass index (BMI), and D-dimer levels were performed to assess the relationship between HALP and DVT. Moderation analysis was used to explore the regulatory effect of HALP on D-dimer levels. HALP levels were inversely associated with DVT occurrence. Patients in higher HALP quartiles (Q3: 33.40–47.93, Q4: 47.93–152.58) exhibited significantly lower odds of DVT ( p < .001). RCS modeling identified a threshold effect, with a sharp increase in DVT occurrence below a HALP level of 33.5. Subgroup analyses revealed that the protective association of higher HALP scores with reduced DVT incidence was consistent across all age groups and was significant in patients with both low and high D-dimer levels. This protective association was particularly strong in males (OR = 0.148) and overweight patients (OR = 0.089). The interaction between HALP and D-dimer was significant ( p < .001), with HALP moderating the association between D-dimer and DVT occurrence. HALP is a strong, independent predictor of post-stroke DVT and moderates the prothrombotic impact of D-dimer. As a low-cost, integrative marker, HALP offers clinical value for early DVT occurrence stratification and individualized prevention strategies in stroke patients.