To Investigate The Relationship Between BALP And Vascular Calcification And Bone Density In Peritoneal Dialysis Patients

Objective:1.To understand the expression level of serum bone-specific alkaline phosphatase(BALP)in peritoneal dialysis patients(PD)and related influencing factors;2.To investigate the relationship between serum BALP and vascular calcification(VC)and bone mineral density in PD patients.Methods:Forty PD patients who at the peritoneal dialysis center of Subei People’s Hospital of Jiangsu province from December 01,2021 to December 30,2022 were included,fasting blood specimens were retained and serum BALP levels were detected,and the enrolled population was divided into 2 groups(low BALP group and high BALP group)according to the median serum BALP levels of the patients.The abdominal aortic calcifications(AAC)were detected by frontal and lateral radiographs of the lumbar spine,and the abdominal aortic calcification score(AACS)was calculated.Coronary artery calcification(CAC)was detected by multi slice spiral computed to-mography(MSCT),and coronary artery calcification score(CACS)was calculated.The coronary artery calcification score(CACS)was calculated.The T values of the left femoral neck and lumbar vertebrae of the selected patients were measured by dual energy X-ray absorptiometry(DXA).The correlation between serum BALP levels and AAC,CAC,and bone mineral density of PD patients was analyzed.Results:A total of 40 PD patients with a median BALP level of 20.85 μg/L were included in this study,and AAC occurred in 60%(24/40)of the patients,of whom 20 had coronary multilayer spiral CT,and 65%(13/20)of them had CAC(CACS >10 points).1.Compared to the low BALP group,patients in the high BALP group had higher blood calcium and lower hemoglobin and high density lipoprotein cholesterol(HDL-C).Pearson correlation analysis showed that serum BALP levels were positively correlated with dialysis age(r=0.294,P=0.045),C-reactive protein(CRP)(r=0.221,P=0.023),AACS(r=0.691,P<0.001),and were negatively correlated with HDL-C(r=-0.444,P=0.004)and T value(r=-0.417,P=0.007).Multi-factor logostic regression analysis showed that AACS(OR:0.471;95%CI:0.260～0.851;P=0.013)were independent influencing factors of serum BALP level.2.The serum BALP level of 24.79(22.49-26.21)μg/L in healthy controls was significantly higher than the serum BALP level of 20.85(19.11-22.31)μg/L in PD patients.Serum BALP level of 22.95(19.94-25.31)U/L in females was significantly higher than serum BALP level of 19.76(17.06 to 21.04)U/L(Z =-1.628,P = 0.104),and the difference was not significant.3.There were significant differences(P<0.05)in age,dialysis age,triglycerides,total cholesterol,HDL-C,low density lipoprotein cholesterol(LDL-C),and BALP between the no calcification(AACS≤0),mild calcification(0<AACS≤4),and moderate to severe calcification groups(AACS>4).The AAC scores of PD patients were positively correlated with BALP(r=0.691,P< 0.001),age(r=0.359,P=0.023),dialysis age(r=0.354,P=0.027),and CRP(r=0.397,P=0.011).Multifactorial logistic regression analysis showed that serum BALP level(OR: 1.856;95% CI: 0.294 to 1.211;P=0.001)was an independent risk factor for AAC in PD patients.The area under the ROC curve for serum BALP level to predict AAC in PD patients was 0.836(95% CI:0.956 to 0.712;P=<0.001).When the detection threshold was 19.66 μg/l,the sensitivity was 87.5% and the specificity was 68.7%.4.Twenty of the 40 PD patients enrolled underwent cardiac CT,and the re sults showed that there were significant differences in age,dialysis age,total ch olesterol,BALP,and uric acid between the three groups: no calcification(CACS≤10),mild to moderate calcification(11<CACS≤400),and severe calcification(C ACS>400)(P<0.05).The CACS of PD patients were positively correlated with BALP(r=0.655,P=0.002),age(r=0.541,P=0.014),dialysis age(r=0.590,P=0.006).Multifactorial logistic regression analysis showed that serum BALP level(O R: 1.574;95% CI: 0.070 to 2.603;P=0.039)was an independent risk factor for CAC in PD patients.The area under the ROC curve for serum BALP levels t o predict CAC in PD patients was 0.849(95% CI: 0.673 to 1.000;P=0.010).When the detection threshold was 18.66 μg/l,the sensitivity was 91.7% and the specificity was 62.5%.5.In PD patients,T values were significantly lower in female patients than in males(P<0.05).T values were significantly lower in menopausal women than in non-menopausal women(P<0.05),and patients in the osteoporosis group had higher serum BALP levels compared with patients in the normal bone mass and reduced bone mass groups,with statistically significant differences(P<0.05).Conclusion:1.Serum BALP levels were positively correlated with AACS and negatively correlated with T values in PD patients.AACS were independent influencing factors of serum BALP levels.The serum BALP level was significantly higher in healthy controls than in PD patients.2.The incidence of AAC and CAC in PD patients was higher,60% and 65%,respectively.Serum BALP level is an independent risk factor for AAC in PD patients.Serum BALP may have some predictive value for the occurrence of AAC in PD patients.Serum BALP level is an independent risk factor for CAC in PD patients.Serum BALP may have some predictive value for the occurrence of CAC in PD patients.3.In PD patients,BMD T values were significantly lower in female patients than in men,and T values were significantly lower in menopausal women than in non-menopausal women.Patients in the osteoporosis group had higher serum BALP levels compared with patients in the normal bone mass and reduced bone mass groups.