Dual-Energy X-Ray Absorptiometry-Derived Advanced Hip Analysis and the Trabecular Bone Score Are Associated With the...

Patients with kidney failure have elevated fracture risk that remains high following kidney transplantation. This study aimed to assess whether dual-energy x-ray absorptiometry-derived advanced hip analysis (AHA) and the trabecular bone score (TBS) improve bone mineral density (BMD)-based post-transplant fracture prediction.

Patients receiving kidney-only or simultaneous pancreas-kidney (SPK) transplants underwent immediate post-transplant dual-energy x-ray absorptiometry to provide BMD, the TBS, and AHA parameters; femoral neck, calcar, and shaft cortical thickness (CTh), and femoral neck buckling ratio (BR), an index of structural instability. Patients received treatment to reduce post-transplant BMD loss, using an established risk algorithm. Hazard ratios were determined using Kaplan-Meier and Cox proportional hazard models.

Of 357 transplant recipients, 289 (83%) received a kidney-only transplant. There were 83 incident fractures over a median of 4.4 years (IQR: 2.5-5.5). Fracture was associated with type 1 diabetes mellitus (p < 0.001), former smoking (p = 0.006), lower 25-hydroxyvitamin D (p = 0.003), BMD at total proximal femur and neck of femur (p < 0.001) and spine (p = 0.008), lower CTh at the calcar (p = 0.005) and shaft (p = 0.023), higher BR (p = 0.016) and lower TBS (p = 0.047). Following multivariable adjustment, type 1 diabetes mellitus, 25-hydroxyvitamin D, smoking, and femoral neck BMD remained significant. Using the BMD-based risk algorithm, inclusion of the BR improved the model fit.

BMD, the TBS, and AHA parameters are associated with incident fracture in kidney-only and SPK transplant recipients. Pre-transplant smoking, lower 25-hydroxyvitamin D and BMD are potentially modifiable factors that could reduce post-transplant fracture risk.