Changes Of Serum Level Of Klotho And Its Relationship With Mineral Metabolism In Patients With Chronic Kidney Disease

Objective:To detect the change of serum level of Klotho in different renal function in patients with chronic kidney disease, explore the interaction with intact parathyroid hormone(iPTH), fibroblast growth factor23(FGF23), serum calcium and serum phosphorus,and to investigate the value of Klotho in the early diagnosis of mineral metabolism in chronic kidney disease.Methods:A total of one hundred and thirty non-dialysis patients with CKD who were admitted in the Nephrology Department or outpatient of the Fujian Provincial People’s Hospital from 2013 September to 2014 December were enrolled.And thirty-five healthy volunteers with examination in the hospital were selected as a control group.Serum level of Klotho and FGF23 were determined by ELISE assay.Serum level of PTH was determined by radioimmunoassay.In addition,serum calcium,serum phosphorus,serum creatinine were detected by BECKMAN-C800 automatic biochemical analyser.Then the estimated glomerular filtration rate(eGFR)was calculated based on MDRD formula.Results:①Compared with control group and CKD stage 1,level of serum creatinine from CKD stage 2 to 5 were higher;and serum creatinine were gradually increased with the advancement of CKD(P<0.05);②Compared with control group and CKD stage 1,levels of serum calcium from CKD stage 3 to 5 were lowe(P<0.05),but there was no statistically significant between the groups(P>0.05);③Compared with control group and CKD stage 1,levels of serum phosphorus and calcium-phosphorus product from CKD stage 4 to 5 were higher(P<0.05);Compared with stage of CKD stage 3,levels of serum phosphorus and calcium-phosphorus product from CKD stage 4 to 5 were higher(P<0.05),but there was no statistically significant between the groups(P>0.05);④Compared with control group and CKD stage 1,level of serum Klotho from CKD stage 2 to 5 was lower,and which was gradually decreased with the advancement of CKD(P<0.05);⑤Compared with control group and CKD stage 1,level of serum FGF23 from CKD stage 2 to 5 was higher,and which was gradually increased with the advancement of CKD(P<0.05);⑥Compared with control group CKD stage 1,level of serum iPTH from CKD stage 3 to 5 was higher(P<0.05);level of serum iPTH in CKD stage 4 was higher than CKD stage 3(P<0.05),and which in CKD stage 5 was higher than CKD stage 4(P<0.05);⑦Correlation analysis:Klotho was negatively correlated with age,serum phosphorus,calcium-phosphorus product,serum creatinine,FGF23 and iPTH(r=-0.575,-0.406,-0.367,-0.567,-0.616,-0.551,respectively,P<0.01),and was positively correlated with serum calcium,eGFR(r=0.242,0.779,respectively,P<0.001).⑧Stepwise multiple linearregression analysis:eGFR and age were independent factors respectivelyfor the level of serum Klotho.Conclusions:1.In patients with chronic kidney disease,the change of serum Klotho precede the change of serum iPTH and serum calcium and phosphorus,suggesting that Klotho may be a early predict indexes for the mineral metabolism in chronic kidney disease.2.The level of serum Klotho and FGF23 changes ang interacts in early stage of chronic kidney disease, which involved in the progess of mineral metabolism in patients with chronic kidney disease,therefore,the early intervention of the balance between serum Klotho and FGF23 may have some significance to correct mineral metabolism.3.eGFR and age were the key factors affecting serum Klotho.