Impact of denosumab on bone high-resolution peripheral quantitative computed tomography (HRpQCT) in hemodialysis patients: a retrospective longitudinal observational study

Abstract Background and Hypothesis Denosumab increases bone mineral density (BMD) in dialysis patients, but the effects on bone microarchitecture using high-resolution peripheral quantitative computed tomography (HRpQCT) and the response factors to treatment are unknown. Methods We analyzed, at a single centre between 2014 and 2024, 19 consecutive patients on hemodialysis having a longitudinal HRpQCT monitoring at the distal tibia and radius. After excluding the presence of osteomalacia based on bone biopsies and ensuring well-controlled parathyroid hormone (PTH) levels, 9 patients with recent fractures were treated with denosumab. Changes in HRpQCT parameters observed over time were analyzed within the denosumab group and were compared to a group of a non-treated patients, using linear mixed models for repeated measures. Baseline histomorphometric parameters were analyzed as predictors of changes in HRpQCT parameters over time in denosumab-treated patients. Results During a median [maximum—minimum] follow-up period of 2.1 [1.0–3.5] years, the 9 denosumab-treated patients had a significant improvement of (i) bone volume to total volume ratio at the distal radius (+1.63% [95% Confidence Interval : 1.11–3.31] per year, p = 0.037) and tibia (+1.13% [0.10–2.28], p = 0.049) , (ii) trabecular volumetric BMD at the distal radius (+1.58 [1.07–3.30], p = 0.039) and tibia (+0.95% [0.11–1.97], p = 0.039), (iii) trabecular number at the distal radius (+1.86% [0.45–3.28], p = 0.017), and (iv) trabecular separation at the distal radius (-1.83% [-3.16–-0.50], p = 0.014). These changes were also significant when compared with those of the untreated group. Changes in cortical parameters did not change significantly over time. At most, changes in trabecular volumetric BMD at the radius was negatively associated with osteoid volume. Conclusion Denosumab improves HRpQCT trabecular bone parameters without significant effect on cortical parameters in dialysis patients.