Endocrine Abstracts

Introduction: Organ transplant recipients are at increased fracture risk compared to general population. Bone mineral density (BMD), predictive of fracture in general population, does not reflect impaired bone quality frequently present in patients with advanced organ failure. Trabecular bone score (TBS) provides surrogate measures of bone microarchitecture and therefore helps to identify persons at risk for fracture among transplant recipients.

Methods: Our retrospective study comprises 186 persons (115 M, 71 W, age 54.4 ± 12.0 y), 34 simultaneous pancreas and kidney (SPK) recipients, 60 kidney and 92 liver recipients, transplanted in 2018. Dual energy X-ray absorptiometry scans (DXA) and TBS measurement were performed with the Lunar Prodigy apparatus within the year of transplantation (Tx). Standard TBS was calculated from DXA images of the lumbar spine.

Results: Osteoporosis of L-spine (T score ≤–2.5) was present in 29/186 persons (16%), osteopenia (T score > −2.5 <–1.0) in 58/186 (31%). Proximal femur osteoporosis was diagnosed in 24/186 (13%), and osteopenia in 71/186 (38%) patients. Mean T score of spine was −0.9 ± 1.5 and T score of hips −1.02 ± 1.2. The lowest values of L spine T score among all were found in liver graft recipients mean-1.2 ± 1.5 vs SPK recipients −0.7±1 (P < 0.05) and for kidney recipients −0.5 ± 1.7 (P < 0.05). SPK recipient had the lowest T score of hips −1.7±1 vs the kidney Tx group (T score −1.0 ± 1.3) (P < 0.01) and for liver graft recipients (T score −0.8 ± 1.2) (P < 0.001). The total group TBS was decreased (mean 1.18 ± 0.1) which corresponds to high risk values <1.23. The worst TBS was found in liver Tx patients 1.13 ± 0.2, which differs significantly from SPK recipients cohort TBS 1.26 ± 0.1 (P < 0.001) and kidney recipients TBS 1.22 ± 0.1 (P < 0.001).

Summary: Bone density of L spine was decreased in 48% and proximal femur in 51% in patients after solid organ transplantation. The low TBS values in comparison with relatively preserved T score point to more prevalent bone microstructure damage present in transplant recipients.