Relationship Between Mineral And Bone Disorder And Cardiac Structure In Patients With Chronic Kidney Disease (CKD) At Stages 3-5

Objective:Current investigation was used to observe the serum mineral levels,include serum calcium and phosphorus,serum parathyroid hormone(PTH),serum25-hydroxy vitamin D(25-OH vit D)and FGF-23,in patients with chronic kidney disease(CKD)at stages 3-5.We also investigated the possible risk factors for heart valve calcification and left ventricular hypertrophy(LVH).Patients and Methods:1.Patiens From June 2015 to December 2016,we selected 134 cases of chronic kidney disease(CKD)patients in the First Affiliated Hospital of Anhui Medical University.According to the chronic kidney disease staging made by the American Kidney Foundation,which recognized internationally.ALL patients were divided into 3 groups,in the CKD 3 stage group,there were 52 petients,in the CKD 4 stage group,there were 31 patients,in the CKD 5 stage group,there were 51 patients.2.Methods(1)Collected clinical data and measured kidney function,serum calcium and phosphorus,serum parathyroid hormone,serum 25-hydroxy vitamin D of all patients.The levels of serum fibroblast growth factor-23(FGF-23)were measured by double antibody sandwich enzyme-linked immunosorbent assay(ELISA).(2)All patients were examined by abdomen lateral radiographs and echocardiography,the calcification of the abdominal aorta,heart valves and the parameters of heart structure were measured.Heart structural parameters mainly included the interventricular septal thickness(IVST),left ventricular end diastolic dimension(LVED),left ventricular end systolic dimension(LVED),left ventricular posterior wall thickness(LVPWT).Then the left ventricular mass fraction of all patients were calculated according to the formula(3)Compared the mineral levels of the three groups and the patients with heart valve calcification in the three groups respectively.(4)Spearson rank correlation analysis was used to find the relevant factors of heart valve calcification and left ventricular hypertrophy.Logsitic regression analysis was used to analyze the possible risk factors of heart valve calcification and left ventricular hypertrophy.(5)Using SPSS 16.0 statistical software,P <0.05 was statistically significant.3.Rusults:(1)The comparison of clinical data and mineral level of the three groups :Compared with CKD at stage 3 patients,the serum phosphorus,calcium and phosphorus,serum parathyroid hormone levels were significantly increased in CKD 4-5 stage(both p <0.01),the difference was statistically significant;but there was no significant difference of FGF-23 and 25-OHVit D among three groups(2)The comparison of the incidence of heart valve calcification in three groups:the incidence of heart valve calcification was significantly higher in CKD 4 stage group(χ2 = 3.874,P = 0.049)and CKD 5 stage group(χ2 = 8.619,P = 0.003)than CKD 3 stage group,The difference was statistically significant.(3)The comparison of the mineral level of the patients with heart valve calcification in the three groups: compared with CKD 3 stage group,the levels of serum phosphorus,calcium and phosphorus products were increased in CKD 4stage and CKD5 stage group(in CKD 4 stage group both P <0.05,in CKD 5 stage group both p <0.01);the serum parathyroid hormone level increased in CKD5group(P <0.05).(4)The risk factors of cardiac valve calcification: Age(r=0.538,p<0.001),serum phosphorus levels(r=0.217,p=0.012),calcium and phosphorus products(r=0.23,p=0.008)and serum FGF-23 levels(r=0.281,p=0.003)were positively correlated with heart valve calcification.Meanwhlie,age(OR = 1.252,P <0.001)and FGF-23 levels(OR = 1.005,P = 0.016)were independent risk factors for heart valve calcification(5))The risk factors of left ventricular mass fraction(LVMI): Serum phosphorus level(r=0.341,p<0.001),calcium and phosphorus product(r=0.312,p<0.001),parathyroid hormone(r=0.296,p=0.001)were positively correlated with LVH,and serum 25-hydroxy vitamin D levels(r=-0.326,p=0.001)was negatively correlated with LVH.PTH(OR = 1.005,P = 0.024)and FGF-23(OR = 1.003,P = 0.022)were independent risk factors for left ventricular hypertrophy.4.Conclusion:(1)In the patients of CKD 3-5 stage,with the decrease of GFR,serum P level,calcium and phosphorus produc,serum PTH level were significantly increased.In the patients with heart valve calcification,the serum phosphorus level and the calcium and phosphorus product also increased.(2)Serum phosphorus level,calcium and phosphorus product,FGF-23 were positively correlated with heart valve calcification,and FGF-23 was independent risk factors for heart valve calcification.(3)Serum phosphorus level,calcium and phosphorus product,PTH were positively correlated with left ventricular hypertrophy.PTH and FGF-23 level were independent risk factor for LVH.