The Role Of Serum Sclerostin Level Changes In Patients With Chronic Kidney Disease And Its Relationship With Calcium-phosphorus Metabolism

Objective:To investigate the relationship between the serum level of sclerostin and kidney function, calcium (Ca), phosphorus (P) and the correlation with other clinical factors in chronic kidney disease. And to explore the role of sclerostin in the metabolism of calcium phosphate or possible mechanism of action, then provide a certain train for early diagnosis and treatment of chronic kidney disease-mineral and bone disorder(CKD-MBD).Methods:According to the standard of NKF-K/DOQI proposed 130 patients with chronic renal disease stage 1-5,another 35 healthy volunteers also included in this study. The levels of serum sclerostin and iPTH were respectively detected by ELISA and radioimmunoassay. Serum calcium (Ca),phosphate (P),albumin(ALB), blood urea nitrogen (BUN) and creatinine (Scr) were detected by Beckman automatic biochemical analyzer; hemoglobin(Hb) was detected by blood analyzer. Calculate the calcium-phosphorus product,then according to the height, weight, age, gender, and serum creatinine, calculate body mass index (BMI), the eGFR was calculated based on the improvement of formula MDRD. Count and analyse the correlation of serum sclerostin and the indicators.Results:(1) Compared with the control group and CKD1 stage, levels of Scr in CKD 2-5 stage groups were higher, while levels of eGFR were lower(P<0.01); (2) Compared with the control group and CKD 1-2 stage, levels of Ca in CKD 3、4、5 stage groups were lower, while levers of P and calcium-phosphorus product were higher in CKD4、5 stage. (3) With the declining of renal function the serum levels of sclerostin gradually increased. Starting from CKD2 the serum sclerostin levels significantly increased than the control group and CKD1 stage, and highest in end-stage renal disease, the difference was statistically significant (P<0.01).(4) Pearson correlation analysis results:serum levels of sclerostin were negatively correlated with eGFR (r=-0.844, P<0.001)and serum Ca (r=-0.424, P＜0.001) and positively correlated with serum creatinine(r=0.906, P<0.001), serum phosphorus levels (r=0.642, P< 0.001), calcium-phosphorus product(r=0.548, P<0.001), iPTH (r=0.402, P＜0.001), age(r=0.163, P＜0.05). but hemoglobin, albumin, BUN, BMI is not relevant with the serum level of sclerostin. (5) Male sclerostin levels were higher than women (P< 0.05); (6) Multiple linear regression analysis:eGFR, Scr, blood calcium and calcium-phosphorus product were independent factors affecting sclerostin levels.Conclusions:From CKD2 stage, with the declining of renal function,the serum level of sclerostin gradually increased.And the change of serum sclerostin levels was superior to serum calcium,serum phosphorus, the calcium-phosphorus product,and the change of iPTH. Or it can be used as a sensitive index for predict early CKD-MBD.Renal function, serum calcium, calcium-phosphorus product were independent factors affecting serum sclerostin.