各期慢性肾脏病患者骨代谢生化指标与骨密度的相关性

目的 观察各期慢性肾脏病（CKD）患者血清骨代谢生化指标与骨密度（BMD）的变化情况及其相关性，探讨这些指标在肾性骨营养不良（ROD）早期诊断中的意义。 方法 78例入选患者共分6组，其中Ccr≥15 ml/min者按CKD临床1~4期分期标准分为4组； Ccr <15 ml/min者按是否行规律血液透析而分为2组。ELISA法测定骨保护素(OPG)。放射免疫法测定血清骨钙素（OC）、降钙素(CT)。化学发光法测定甲状旁腺素(iPTH)。6组患者中共47例行腰椎及股骨不同部位BMD测定。分析各组患者以上指标的差异及其相关性。 结果 （1）血清OPG、iPTH及磷分别从CKD 3、4、5期开始显著上升（P < 0.01），其中OPG在血液透析后达（5.10±1.34）ng/L，显著高于透析前的（3.35±0.76） ng/L，差异有统计学意义（P < 0.05）。各期CKD患者血清OC、CT、钙及碱性磷酸酶水平差异无统计学意义，而血液透析可使OC显著升高（P < 0.05）。股骨沃德三角BMD在 CKD 4期患者下降至0.77±0.09，显著低于CKD 1期患者的1.15±0.05，差异有统计学意义（P < 0.01），而血液透析不影响其水平。（2）血清OPG与Ccr、磷、iPTH、OC呈负或正相关（r分别为-0.70、0.51、0.39、0.36，均P < 0.01）。股骨沃德三角BMD与血清iPTH、OC呈负相关（r分别为-0.59、-0.51，均P < 0.01）；与血清磷、OPG亦呈负相关（r分别为-0.45、-0.48，均P < 0.05）。 结论 CKD患者骨代谢生化指标与BMD均随Ccr下降而出现明显异常，这些变化之间存在一定的相关性。血清OPG改变早于iPTH及BMD，在ROD的早期诊断中意义最大。血液透析可使血清OPG、OC水平升高，但不影响BMD水平。

Correlation between serum bone metabolism biomarkers and bone mineral density in chronic kidney disease patients with different stages

Objective To investigate the correlation between serum bone metabolism biomarkers and bone mineral density (BMD) in chronic kidney disease (CKD) patients with different stages. Methods Seventy-eight CKD patients were enrolled in this study and were assigned to different groups according to their ereatinine clearance (Cer). Patients with Cer ≥ 15 ml/min were divided into 4 groups based on clinical CKD 1-4 stage standard, and those with Ccr<15 ml/min were divided into two groups of hemodialysis (HD) and non-HD. Their levels of serum calcium, phosphorus, alkalinity phosphatase (ALP), urea, Ser, osteocalein (gla-protein, OC), calcitonin (CT), intact parathyroid hormone (iPTH), osteoprotegerin (OPG) and BMD were detected respectively. Results (1) The serum levels of OPG, iPTH and phosphorus increased significantly in stage 3, 4, 5, respectively (P<0.01), and serum OPG level was elevated to (5.1±1.34) ng/L after HD, which was significantly higher than (3.35±0.76) ng/L before HD (P<0.05). The levels of serum OC, CT, calcium, ALP were not significantly different among patients with different CKD stages, while the level of OC was elevated in HD patients (P<0.05). The femoral WARDS triangle BMD of CKD stage 4 patients decreased to 0.77±0.09, which was less than the value of CKD stage 1 patients (P<0.01), with litde influence from hemodialysis treatment. (2) The level of serum OPG was positively correlated with the levels of serum phosphorus, iPTH, OC (r = 0.51, 0.39, 0.36,all P<0.01), and it was negatively correlated with the level of Ccr (r =-0.70, P<0.01). The femoral WARDS triangle BMD was negatively correlated with the levels of iPTH, OC, phosphorus and OPG (r =-0.59,-0.51,-0.45,-0.48, all P<0.05). Conclusions Most of serum bone metabolism biomarkers change according to the declined level of Cer. Compared with serum phosphorus, the levels of iPTH, BGP and femoral WARDS triangle BMD, serum OPG may be early diagnosticmarkers of renal osteodystrophy in CKD patients.