The Relationship Between Serum Sclerostin And Dickkopf-1 And Abdominal Aortic Calcification In Peritoneal Dialysis Patients

Objective: The study was to investigate the relationship between serum sclerostin and DKK1 and calcification of abdominal aorta in patients with peritoneal dialysis(PD),which could provide a theoretical basis for assessing cardiovascular disease in PD patients.Methods:57 patients with PD were selected which underwent peritoneal dialysis for 3 months at least.The clinical data were collected,and the abdominal aorta calcification was calculated by lateral abdominal plain films.The abdominal aorta calcification score(AACs)were used to evaluate the calcification of the abdominal aorta.AACs were divided into 4 groups(no calcification group,mild calcification group,moderate calcification group,severe calcification group).There were 31 healthy persons as the control group.Serum sclerostin and DKK1,25-OH-VD concentrations were detected by ELISA.Multiple linear regression analysis was used to analyze the risk factors for calcification of abdominal aorta in PD patients.The receiver operating curve was used to evaluate the accuracy and specificity of sclerostin and DKK1 in the diagnosis of calcification of abdominal aorta.Results:1.Comparison between PD group and healthy control group:There were 57 patients in PD group(male 38 cases,female 19 cases),with the mean age 54(45,62);There were 31 patients in control group(male16 cases,female 15 cases),mean age 46(42,56);There was no statistical difference in gender and age between the two groups.The serum Sclerostin concentration was 6.59(4.8,8.6)ng/ml in the PD group and 9.21(5.8,10.5)ng/ml in the healthy control group.The serum Sclerostin of PD group was lower than the healthy control group(P<0.01).The serum DKK1 concentration in the PD group was(106.82±3.21)ng/ml,and that in the healthy controlgroup was(126.4±2.01)ng/ml.The serum DKK1 of PD group was lower than the healthy control group(P<0.01).2.Abdominal aortic calcification:57 patients with PD,26 patients(45.6%)had vascular calcification in of which 10 patients had mild calcification,10 had moderate calcification,and 6had severe calcification.Among them,the calcification of 8 patients(30.76%)occurred in the first lumbar segment,14 patients(53.84%)occurred in the second lumbar segment,19 patients(73.07%)occurred in the third lumbar segment,and 22 patients(84.61%)occurred in the fourth lumbar segment.Abdominal aortic calcification mainly occurred in the fourth lumbar spine,and the number of AAC gradually increased from the first lumbar spine to the fourth lumbar spine.3.Comparison between 4 groups of PD patientsThe PD patients were divided into 4 groups by the AACs(non-calcified、mild calcification、moderate calcification、severe calcification).The levels of Sclerostin in the four groups were 7.5(4.9,10.6)ng/ml,7.5(6.3,8.8)ng/ml,5.2(4.0,6.8)ng/ml,and 4.8(3.7,5.3)ng/ml.The DKK1 levels in the four groups were 121.3±3.7 ng/ml,96.9±4.4 ng/ml,91.4±4.9 ng/ml,and 74.0±5.2ng/ml.The Sclerostin and DKK1 levels gradually decreased with the severity of calcification in the abdominal aorta.The difference was statistically significant,P<0.05.The rank correlation analysis showed that AACs were positively correlated with age(r=0.367,P<0.01)and negatively correlated with Sclerostin(r=-0.373,P<0.01)and DKK1(r=-0.692,P<0.01).4.Analysis of risk factors of abdominal aortic calcification in PD patients:The low serum DKK1(OR=0.905,95% CI 0.858-0.955,P<0.01)and higher age(OR=1.087,95%CI1.018~1.162,P<0.05)were independent risk factor for abdominal aortic calcification.After adjusting for general conditions and related clinical biochemical indicators,there were still statistical differences.5.The accuracy of Serum Sclerostin and DKK1 diagnosis of abdominal aortic calcification:ROC-AUC of serum Sclerostin for abdominal aortic calcification was0.658(95%CI0.515~0.80,P<0.05),(cutoff7.785ng/ml,accuracy84.6%,specificit y48.4%).ROC-AUC of serum DKK1 for abdominal aortic calcification was0.875(95%CI0.787~0.963,P<0.01),(cutoff106.825ng/ml,accuracy84.6%,specif icity 77.4%).Conclusions:1.Serum Sclerostin and DKK1 levels were lower in peritoneal dialysis patients than in healthy people;2.Abdominal aortic calcification mainly occurred in the fourth lumbar spine,and the number of AAC gradually increased from the first lumbar spine to the fourth lumbar spine;3.The low serum DKK1 concentration in patients with PD was an independent risk factor for abdominal aortic calcification;Sclerostin and DK K1 concentrations were negatively correlated with abdominal aortic calcification,and serum Sclerostin and DKK1 concentrations might help diagnose abdominal aortic calcification.