骨转换生化指标与原发性肾病综合征并发肾性骨营养不良的相关性研究

Relationship between the changes of biochemical markers of bone turnover and renal osteodystrophy in patients with primary nephrotic syndrome

目的 探讨原发性肾病综合征（PNS）患者肾性骨营养不良（ROD）与骨转换生化指标的关系,评价检测这些指标在PNS患者中的临床价值.方法 应用双能X线骨密度仪分别测定30例PNS患者和50例健康体格检查者的腰椎和股骨BMD,检测血清中骨转换生化指标总Ⅰ型前胶原氨基端延长肽（TP Ⅰ NP）、Ⅰ型胶原羧基端肽β特殊序列（β-CTx）、完整PTH（iPTH）及血清钙、血清磷、ALP、25-羟基维生素D3（25-OH-VD3）、血清β2微球蛋白（β2-MG）、尿微量白蛋白/肌酐比值（UA/Cr）等,分析引起ROD的相关危险因素.采用两独立样本t检验、多元线性回归及偏相关分析对数据进行统计学处理.结果 PNS组腰椎L1～4总BMD、左侧股骨颈和左侧股骨大转子BMD均低于对照组（＜40岁组：t=6.162、5.583和3.891,≥40岁组：t=5.923、5.324和3.129;均P＜0.05）.PNS组TPⅠNP、β-CTx、iPTH、ALP、β2-MG、UA/Cr较对照组升高（＜40岁组：t=2.738～ 10.129; ≥40岁组：t=3.226～ 12.581;均P＜0.05）,血清钙、25-OH-VD3均低于对照组（＜40岁组：t=3.624和7.223;≥40岁组：t=2.011和2.564;均P＜0.05）;血清磷差异无统计学意义（t=0.811和0.513,均P＞0.05）;PNS组内相关分析显示,TP ⅠNP与β-CTx、iPTH、ALP、UA/Cr、β2-MG呈正相关（r=0.512～ 0.682,均P＜0.01）,与血清钙、25-0H-VD3呈负相关（r=-0.314、-0.562,均P＜0.01）;β-CTx与iPTH、ALP、UA/Cr、β2-MG呈正相关（r=0.459～0.618,均P＜0.01）,与血清钙、25-OH-VD3呈负相关（r=-0.212、-0.589,均P＜0.01）.ALP、UA/Cr、β2-MG与血清iPTH呈正相关（r=0.410、0.606、0.508,均P＜0.05）,血清钙、25-OH-VD3与血清iPTH呈负相关（r=-0.315、-0.516,均P＜0.05）.结论 PNS患者存在不同程度BMD下降,联合检测TP Ⅰ NP、β-CTx和BMD有助于PNS患者并发ROD的早期诊断.

Objective To investigate the relationship between the biochemical markers of bone turnover and renal osteodystrophy （ROD） in patients with primary nephrotic syndrome （PNS）.Methods A total of 30 patients with PNS and 50 healthy subjects （controls） were included in the study.The BMD of lumbar vertebrae and femur was measured by dual-energy X-ray absorptiometry.The levels of total procollagen type Ⅰ amino-terminal propeptide （TP Ⅰ NP）,β-isomerized carboxyterminal propeptide （β-CTx）,intact PTH （iPTH）,serum calcium,serum phosphorus,ALP,25-OH-Vitamin D3 （25-OH-VD3）,β2-micro-globulin（β2-MG）,and ratio of urinary to creatinine （UA/Cr） were measured and calculated.The risk factors related to ROD in PNS patients were analyzed.Two-sample t test,multiple linear regression and partial correlation analysis were used to analyze data.Results The BMD values of lumbar vertebrae and femur in the PNS group were significantly decreased compared with those in controls （t =6.162,5.583,3.891 （〈40 years）,5.923,5.324,3.129 （≥40 years）,all P〈0.05） and the serum levels of TPⅠNP,β-CTx,iPTH,ALP,β2-MG and UA/Cr in the PNS group were significantly higher than those in controls （t：2.738-10.129（〈40 years）,3.226-12.581 （≥40 years）,all P〈0.05）,and the levels of serum calcium and 25-OH-VD3 in the PNS group were significantly lower than those in controls （t =3.624,7.223 （〈40 years）,2.011,2.564 （≥40 years）,all P〈0.05）.But there was no significant difference for serum phosphorus between the 2 groups （t=0.811,0.513,both P〉0.05）.TP Ⅰ NP was positively correlated with β-CTx,iPTH,ALP,UA/Cr,β2-MG（r：0.512-0.682,all P〈0.01）,and TP Ⅰ NP was negatively correlated with serum calcium and 25-OH-VD3（r=-0.314,-0.562,both P〈0.01）in the PNS group.β-CTx was positively correlated with iPTH,ALP,UA./Cr,β2-MG（r：0.459-0.618,all P〈0.01）,and negatively correlated with serum calcium and 25-OH-VD3（r=-0.212,-0.589,both P〈0.01）.The iPTH was positively correlated with ALP,UA/Cr and β2-MG （r =0.410,0.606,0.508,all P〈0.05）,and negatively correlated with serum calcium and 25-OH-VD3（r=-0.315,-0.516,both P〈0.05）.Conclusions The BMD in PNS patients is lower than that in healthy subjects.Combined measurement of TP Ⅰ NP,β-CTx and the BMD is helpful for the diagnosis of ROD in PNS patients.