Endocrine Abstracts

Objective: Trabecular bone score (TBS) is associated with an increased risk of prevalent and incident fractures. It has a role of fracture assessment in secondary osteoporosis related to diabetes, acromegaly and hyperparathyroidism and in glucocorticoid-induced osteoporosis. However, it is understudied as a marker of bone health in heart transplanted patients. The aim of our pilot study was to evaluate the effects of zoledronic acid (ZA) on bone health including TBS in this population.

Materials and methods: We included 13 treatment naïve (TN) patients (9 men, 4 women) and 9 patients (8 men, 1 woman) who already received at least one application of ZA (TR). All patients received cholecalciferol, alfacalcidiol and calcium supplements. We measured TBS, bone mineral density (BMD), corrigated calcium (cCa), estimated glomerular filtration (eGF), c-terminal telopeptide (CTX), procollagen type I N propeptide (PINP), intact parathyroid hormone (iPTH).

Results: Groups were matched by age. Time from transplantation was 6.2±5.4 months for TN and 76.1±66.1 month for TR. In TR compared to TN, there were lower CTX 1151.9±557.7 pmol/L; 2936.6±1763.0 pmol/L; P<0.009), lower Ca (2.11±1.0 mmol/L; 2.24±0.7 mmol/L; P<0.002), and higher iPTH (83.6±46.1 ng/L; 44.8±18.9 ng/L; P<0.017). There were no significant difference in TBS (1.285±0.08; 1.274±0.13), lumbar BMD (0.935±0.08 g/cm²; 0.901±0.19 g/cm²), neck BMD (0.681±0.09 g/cm²; 0.731±0.14 g/cm²), hip BMD (0.846±0.12 g/cm²; 0.893±0.16 g/cm²), T-score on lumbar (−1.4±0.7 SD; −1.6±1.8 SD), neck (−1.7±0.6 SD; −1.4±1.0 SD) and hip (−1.0±0.8 SD; −0.8±1.0 SD), PINP (39.39±13.53; 52.64±44.33), and eGF (76±14 mL/min/1.73 m²; 70±18 mL/min/1.73 m²), between TR and TN. No patients had fractures in the time of observation.

Conclusions: CTX was significantly lower in TR than in TN, whereas TBS and BMD were comparable between the groups. Lower CTX and lack of the differences in TBS and BMD despite the longer exposure to corticosteroid and immunosuppressive treatment in TR, imply a protective role of ZA on bone health after heart transplant. Ca was lower and iPTH was higher in patients treated with ZA, indicating that treatment with vitamin D and calcium should be more intensively tailored when patients receive ZA to prevent secondary hyperparathyroidism. The role of TBS in this population needs further investigation.