Dolgos Szilveszter, Hartmann Anders, Bønsnes Stine, Isaksen Gunhild Aker, Godang Kristin, Ueland Thor, Pfeffer Per, Bollerslev Jens
Medical Center, Rikshospitalet-Radiumhospitalet, University of Oslo, Oslo, Norway.
Scand J Clin Lab Invest. 2009;69(2):161-7. doi: 10.1080/00365510802449634.
Serum osteocalcin and C-terminal telopeptides of type-1 collagen (CTX-1) are known markers of bone turnover, whereas the role of fibroblast growth factor 23 (FGF-23) is yet unknown. We investigated early changes in bone mass and the association of these biochemical markers and FGF-23 with bone loss following renal transplantation (RTx).
In 44 first-kidney allograft patients, BMD was measured by dual-energy X-ray absorptiometry in the lumbar spine (LS), total femur (TF) and total body (TB) at baseline and 10 weeks post-transplant. Serum osteocalcin, CTX-1, intact FGF-23, intact parathormone (iPTH) and 25-hydroxyvitamin D (25-OHD) levels were measured. Associations were tested by correlation and multiple linear regression.
We found a significant (p<0.05) decrease in bone mass in LS (2.6 %), TF (2.1 %) and TB (1.4 %). Osteocalcin (0.95 versus 1.56 nmol/L) and CTX-1 (1.05 versus 1.47 ng/mL) levels increased significantly, while serum FGF-23 and iPTH decreased. Serum osteocalcin and CTX-1 were significantly associated at both baseline and follow-up. Baseline osteocalcin and CTX-1 were independently associated with bone loss in TB and TF, respectively. Neither iPTH nor 25-OHD showed consistent association with bone loss. FGF-23 was not related to change in bone mass or to biochemical markers of bone turnover.
Our results confirm an early decrease in bone mass with high bone resorption rate after RTx. Osteocalcin and CTX-1 are associated with bone loss in the early post-transplant period; thus, these markers may be a reasonable choice for routine assessment of bone turnover in this setting. The role of FGF-23 remains to be further elucidated.
血清骨钙素和1型胶原C端肽（CTX-1）是已知的骨转换标志物，而成纤维细胞生长因子23（FGF-23）的作用尚不清楚。我们研究了肾移植（RTx）后骨量的早期变化以及这些生化标志物和FGF-23与骨质流失的关联。
对44例首次接受肾脏同种异体移植的患者，在基线时以及移植后10周，通过双能X线吸收法测量腰椎（LS）、全股骨（TF）和全身（TB）的骨密度。测量血清骨钙素、CTX-1、完整FGF-23、完整甲状旁腺激素（iPTH）和25-羟基维生素D（25-OHD）水平。通过相关性和多元线性回归检验关联。
我们发现LS（2.6%）、TF（2.1%）和TB（1.4%）的骨量显著下降（p<0.05）。骨钙素（0.95对1.56 nmol/L）和CTX-1（1.05对1.47 ng/mL）水平显著升高，而血清FGF-23和iPTH下降。血清骨钙素和CTX-1在基线和随访时均显著相关。基线骨钙素和CTX-1分别与TB和TF的骨质流失独立相关。iPTH和25-OHD均未显示与骨质流失有一致的关联。FGF-23与骨量变化或骨转换生化标志物无关。
我们的结果证实RTx后骨量早期下降且骨吸收速率高。骨钙素和CTX-1与移植后早期的骨质流失相关；因此，在这种情况下，这些标志物可能是常规评估骨转换的合理选择。FGF-23的作用仍有待进一步阐明。
