Osteoporosis and Bone Metabolism Unit, Department of Endocrinology, Renal Transplant Osteoporosis Clinic, Singapore General Hospital, Singapore City, Singapore.
Division of Medicine, Health Services Research Unit (HSRU), Singapore General Hospital, Singapore City, Singapore.
Clin Transplant. 2019 Oct;33(10):e13671. doi: 10.1111/ctr.13671. Epub 2019 Aug 16.
The evolution of trabecular bone score (TBS) and bone mineral density (BMD) over the first 5 years after renal transplantation was prospectively evaluated in 164 patients. Dual energy X-ray absorptiometry (DXA) scans were performed at 0, 6, 12, 24, and 60 months. Cumulative steroid dose, serum 25(OH)D, calcium, parathyroid hormone, and total ALP levels at these time points were checked. Incident fractures were identified from X-rays/vertebral fracture assessments. Mean (SD) age, TBS, and lumbar spine BMD at baseline were 47.11 (9.53), 1.424 (0.097), and 0.935 (0.183) gm/cm , respectively. Baseline TBS was lower in tertiary 1.38 (0.07) vs secondary hyperparathyroidism 1.43 (0.01) vs post-parathyroidectomy 1.46 (0.11); P = .035. Trabecular bone score and BMD significantly decreased from baseline->6 months, changes after that at consecutive time points were non-significant. 11% had incident fractures during the follow-up period, majority being metatarsal with no vertebral or hip fractures noted. This first prospective evaluation of TBS and BMD evolution at multiple time points over 5 years suggest that microarchitectural and bone density deteriorations post-renal transplantation stabilize after 6 months. Stabilization of these parameters could partially account for the absence of major fractures noted in this Asian population. Possible genetic and ethnic differences in fracture risk between Asian and Caucasian renal transplant patients have to be explored through large population-based studies.
本研究前瞻性评估了 164 例肾移植患者在移植后 5 年内的小梁骨评分(TBS)和骨密度(BMD)演变。在 0、6、12、24 和 60 个月时进行双能 X 线吸收法(DXA)扫描。检查了这些时间点的累积类固醇剂量、血清 25(OH)D、钙、甲状旁腺激素和总碱性磷酸酶水平。通过 X 射线/椎体骨折评估确定新发骨折。基线时平均(SD)年龄、TBS 和腰椎 BMD 分别为 47.11(9.53)、1.424(0.097)和 0.935(0.183)gm/cm。基线 TBS 在三级 1.38(0.07)与二级甲状旁腺功能亢进 1.43(0.01)与甲状旁腺切除术后 1.46(0.11)之间较低,P=0.035。TBS 和 BMD 从基线到 6 个月显著降低,此后在连续时间点的变化无统计学意义。在随访期间,11%的患者发生了骨折,大多数是跖骨骨折,未观察到椎体或髋部骨折。这是首次对 5 年内多个时间点的 TBS 和 BMD 演变进行的前瞻性评估,表明肾移植后微结构和骨密度的恶化在 6 个月后趋于稳定。这些参数的稳定可能部分解释了亚洲人群中未观察到主要骨折的原因。需要通过大型基于人群的研究来探索亚洲和高加索肾移植患者在骨折风险方面的遗传和种族差异。