Cross-Sectional Study Of Osteoporosis And Cardiovascular Calcification In Patients With Chronic Kidney Diseases At Different Stages

Background and ObjectiveChronic kidney disease(CKD)is a kind of chronic progressive metabolic disease.Mineral and bone disorder(MBD)is one of the common complications of CKD.The main manifestations are metabolic disorders such as serum calcium(CA),phosphorus(P),parathyroid hormone(PTH).With the gradual decrease of renal function in patients with CKD-MBD,the metabolic disorders of Ca,P,PTH,etc.,will affect the process of bone formation and conversion,resulting in the increased risk of osteoporosis and cardiovascular calcification,which will seriously affect the prognosis,survival and quality of life of patients.This study analyzed the relationship between the changes of serum Ca,P and iPTH levels and osteoporosis and cardiovascular calcification in patients with CKD stage 3-5,and further explored the role of bone metabolic markers in the evaluation of osteoporosis and cardiovascular calcification in different CKD patients,in order to provide a theoretical basis for the treatment of clinical CKD patients.MethodsA total of 368 CKD patients at stages 3-5 treated in the First Affiliated Hospital of Chongqing Medical University and Fuling Central Hospital in Chongqing from July 2017 to January 2018 were enrolled.According to the estimated glomerular filtration rate(EGFR),the patients were divided into CKD stage 3 group,CKD stage 4 group and CKD stage 5 group(CKD stage 5 dialysis group and non dialysis group).In addition,60 healthy subjects who underwent physical examination in the First Affiliated Hospital of Chongqing Medical University and Fuling Central Hospital of Chongqing Municipality were selected as control group.The general data such as age,gender,body mass index(BMI),primary disease and complications were recorded and collected.Serum creatinine(SCR),blood urea nitrogen(BUN),albumin(ALB),CA,P,bone alkaline phosphatase(BALP),intact parathyroid hormone(iPTH),procollagenⅠN-terminal peptide(PⅠNP)and serum creatinine(SCR)were measuredβ-Collagen specific sequence(β-collagen specific sequence,β-CTX)and other bone metabolism related markers.The incidence of osteoporosis,vascular calcification and cardiac valve calcification were detected by dual energy X-ray absorptiometry and color Doppler ultrasound.Useχ~2Logistic regression analysis was used to analyze the risk factors of osteoporosis and cardiovascular calcification.Pearson correlation analysis was used to analyze the correlation between bone metabolism related markers and osteoporosis and cardiovascular calcification.Results(1)Bone metabolism related indicators:(1)compared with the control group,bun,SCR,P,iPTH,BALP,PⅠNPβ-CTX increased significantly with the deterioration of renal function(P<0.05),while EGFR and Ca levels were lower than those in the control group,and decreased with the deterioration of renal function(P<0.05);(2)There was no significant difference in serum Ca,P,iPTH,PⅠNP levels between dialysis group and non dialysis group(P>0.05)β-CTX level was higher than that of non dialysis group(P<0.05).(2)Analysis of the incidence and risk factors of osteoporosis:(1)there was no difference in the incidence of osteoporosis among CKD 3,CKD 4,CKD 5 non dialysis and CKD 5 dialysis groups(P>0.05);(2)High iPTH and BALP levels were risk factors for osteoporosis(P<0.05),and high EGFR levels were protective factors for osteoporosis(P<0.05).(3)Analysis of cardiovascular calcification and risk factors:(1)the incidence of vascular calcification and cardiac valve calcification in CKD 5dialysis group was significantly higher than that in CKD 3-4 group and CKD 5 non dialysis group(P<0.05);(2)Hyperlipidemia and the increased levels of P,iPTH and BALP were the risk factors of cardiovascular calcification(P<0.05),and the high level of EGFR was the protective factor of cardiovascular calcification(P<0.05).(4)Correlation of bone metabolic markers with osteoporosis and cardiovascular calcium:(1)EGFR was positively correlated with serum Ca level(r=0.219,P<0.05)in patients with CKD stage 3-5,and positively correlated with serum P,iPTH,BALP,PⅠNPβ-CTX level was negatively correlated(r=-0.439,-0.527,-0.518,-0.384,-0.417,P<0.05);(2)The occurrence of osteoporosis,vascular calcification and cardiac valve calcification was negatively correlated with EGFR(r=-0.382,-0.641,-0.421,P<0.05),blood Ca(r=-0.244,-0.327,-0.273,P<0.05),and was negatively correlated with P(r=0.303,0.495,0.420,P<0.05),iPTH(r=0.457,0.695,0.583,P<0.05),BALP(r=0.441,0.683,0.526,P<0.05)PⅠNP(r=0.333、0.512、0.442,P<0.05)、β-CTX(r=0.359,0.471,0.428,P<0.05)was positively correlated;(3)There was a positive correlation between osteoporosis and cardiovascular calcification(CC=0.251,P<0.05).Conclusion(1)With the progression of kidney disease in CKD stage 3-5 patients,blood p,iPTH,BALP,PⅠNPβ-CTX level increased significantly,blood Ca level decreased,the incidence of vascular calcification and cardiac valve calcification also increased significantly.(2)Low EGFR,elevated iPTH and BALP levels were independent risk factors for osteoporosis in CKD patients.Hyperlipidemia,low EGFR and high P,PTH and BALP levels were independent risk factors for cardiovascular calcification in CKD patients.(3)Blood p,iPTH,BALP,PⅠNP and bone metabolism related indexes in CKD patientsβ-The increase of CTX level was positively correlated with the occurrence of osteoporosis and cardiovascular calcification,and the increase of blood Ca level was negatively correlated with the occurrence of osteoporosis and cardiovascular calcification.The increase of CTX level was positively correlated with the occurrence of cardiovascular calcification in CKD 3-5 patients,and the increase of blood p,iPTH,BALP,PⅠNP,β-The increase of CTX level and the decrease of Ca may be related to the increase of incidence rate of osteoporosis and cardiovascular calcification in CKD 3～5 stage patients.