Experimental Evaluation of <em>ABCB1</em> C3435T (rs1045642) Gene Polymorphism and Its Association with Postoperative Analgesia in Hip Replacement Surgery

This study investigated the association between the ABCB1 (MDR1) C3435T (rs1045642) gene polymorphism and postoperative analgesia in patients undergoing hip replacement surgery. A total of 100 patients who underwent hip replacement in our hospital between January 2023 and January 2024 received postoperative patient-controlled intravenous analgesia with sufentanil. Preoperative serum samples were collected, and genomic detection was performed using the TaqMan SNP genotyping assay. According to the C3435T genotype, patients were classified into wild-type homozygotes (CC group), mutant heterozygotes (CT group), and mutant homozygotes (TT group). Clinical parameters, including baseline characteristics, Visual Analogue Scale (VAS) pain scores, sufentanil consumption, serum pain mediators (prostaglandin E2 (PGE2), substance P (SP), and β-endorphin (β-EP)), Hamilton anxiety and depression scores, sleep quality, and the incidence of adverse events within 24 h after surgery were compared among groups. Baseline characteristics were similar across groups (p > 0.05). VAS scores, sufentanil dosage, and serum PGE2, SP, and β-EP levels at 24 h were significantly lower in CT and TT groups compared with the CC group (p < 0.05). The TT group also exhibited reduced Hamilton anxiety and depression scores relative to both CC and CT groups (p < 0.05), whereas the CT group showed higher anxiety and depression scores than the CC group (p < 0.05). Sleep quality and adverse event rates were not significantly different among groups (p > 0.05). These findings suggest a potential association between the ABCB1 (MDR1) C3435T (rs1045642) polymorphism and variability in postoperative analgesic efficacy. Patients carrying the TT genotype tended to experience better analgesia, lower sufentanil requirements, and improved psychological outcomes. Although these results are promising, they should be interpreted with caution due to the small sample size and single-center design. Further large-scale studies are warranted to confirm these observations and evaluate their clinical applicability.