To systematically review the research progress on biomarkers for delirium risk prediction in hip fracture patients, clarify their concepts, classifications, and clinical application value, and provide a theoretical basis for early identification of high-risk patients and precise intervention.

Relevant studies were systematically searched in databases including PubMed, Cochrane Library, Web of Science, CINAHL, Embase, CNKI, VIP, Wanfang, and CBM, with the search timeframe spanning from database inception to December 31, 2024. Two researchers independently screened the literature, assessed quality, and extracted data, followed by a summarized analysis of the included studies.

A total of 19 studies were included, covering three major categories of biomarkers: 1. Inflammatory markers: Neutrophil-to-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), C-reactive protein (CRP), and cytokines (IL-6, TNF-α) were significantly associated with delirium risk; 2. Blood biochemical markers: Serum albumin, serum S100 calcium-binding protein A12 (S100A12), and serum neurofilament light chain protein (NfL) predicted delirium risk by reflecting nutritional status and central nervous system injury; 3. Cerebrospinal fluid markers: Tissue inhibitor of metalloproteinases-1 (TIMP-1) and soluble triggering receptor expressed on myeloid cells 2 (sTREM2) may contribute to delirium onset through neuroinflammatory pathways.

Current evidence supports the predictive value of biomarkers for delirium risk in hip fracture patients, but three major limitations exist: 1. Significant variability in cutoff values across studies (e.g., NLR thresholds); 2. Lack of dynamic monitoring data; 3. Insufficient research on multi-biomarker combined prediction models. Future multicenter prospective studies are recommended to develop combined biomarker prediction models and establish evidence-based clinical guidelines to facilitate the translation of biomarker-based delirium risk prediction into clinical practice.