Down-regulation of SERPINH1 and ROCK1 in chronically immobilized elderly patients with intertrochanteric hip fracture

Objective: Venous thromboembolism (VTE) is a major complication after hip fracture, and immobilization is traditionally considered a key risk factor. This study aimed to evaluate SERPINH1 (HSP47) and ROCK1 gene expression levels in elderly patients with intertrochanteric hip fracture according to pre-fracture mobility status. It was hypothesized that chronically immobilized (pre-fracture) elderly patients would demonstrate reduced expression of these genes, potentially indicating a molecular pattern associated with thromboembolic risk.

Methods: This prospective observational study included 90 patients aged ≥65 years with intertrochanteric femur fractures treated by proximal femoral nailing. Based on pre-fracture activity levels, patients were categorized into Group A (low mobility, n = 30), Group B (moderate mobility, n = 30), and an age-matched healthy control group (Group C, n = 30). Peripheral blood was drawn within 6 hours of admission. Total RNA was isolated, cDNA was synthesized, and qRT-PCR was performed for SERPINH1 and ROCK1 gene expression analysis. Demographic data, Charlson Comorbidity Index (CCI), EQ-5D scores, and routine laboratory test results were recorded. Patients were clinically monitored for VTE during 6 months of follow-up, and diagnostic imaging was performed only when clinically suspected.

Results: SERPINH1 expression was significantly lower in Groups A and B compared to the control group (Group A vs. C: P = .010; Group B vs. C: P = .037). ROCK1 expression also showed significant differences (P < .001): Group A vs. C (P < .001), Group A vs. B (P = .027), Group B vs. C (P = .044). In Group B, SERPINH1 expression correlated positively with age (r = .437; P = .016). Mortality analysis showed that deceased patients had higher CCI (P = .002), lower EQ-5D (P = .030), and lower albumin levels (P = .016). During the 6-month follow-up period, no clinically diagnosed pulmonary embolism or deep vein thrombosis was observed.

Conclusion: These findings suggest that in chronically immobilized elderly hip fracture patients, reduced SERPINH1 and ROCK1 gene expression may represent a molecular pattern potentially associated with thromboprotection, possibly contributing to modulation of pro-coagulant pathways in immobile states. Targeting HSP47-related pathways may provide a potential avenue for developing alternative antithrombotic strategies with reduced wound-related complications; however, further large-scale clinical studies are required to confirm these findings.

Cite this article as: Gedik B, Demirkale İ, Tanoğlu EG, Gürbüz H. Down-regulation of SERPINH1 and ROCK1 in chronically immobilized elderly patients with intertrochanteric hip fracture. Acta Orthop Traumatol Turc., 2026; 60(3), 0747, doi: 10.5152/j.aott.2026.25747.