Clinical Characteristics And Risk Factors Of Abdominal Aortic Calcification In Patients With Maintenance Hemodialysis

Objective: To study the clinical characteristics of abdominal aortic calcification in patients with maintenance hemodialysis(MHD),to find risk factors for vascular calcification in MHD patients and non-invasive serological markers that can be used to evaluate calcification,and to provide early diagnosis and prevention of vascular calcification of MHD patients to provide more theoretical basis.Methods: A total of 107 patients undergoing maintenance hemodialysis in the department of nephrology of our hospital from March to October 2019 were collected,and general clinical data and laboratory tests were collected for all patients,including gender,age,height,weight,and the primary cause of chronic renal failure,whether accompanied by diabetes,dialysis age,pre-dialysis blood pressure,hemoglobin,urea,creatinine,uric acid,serum albumin,total cholesterol,triglycerides,high density lipoprotein cholesterol(HDL-C),low density lipoprotein cholesterol(LDL-C),fasting blood glucose,blood calcium,blood phosphorus,blood magnesium,alkaline phosphatase(AKP),parathyroid hormone(PTH),C-reactive protein(CRP),and calculate pulse pressure difference,body mass index(BMI),calcium and phosphorus product.Serum bone morphogenetic protein 2(BMP2),bone morphogenetic protein 4(BMP4),bone morphogenetic protein 7(BMP7),soluble α-klotho protein(α-klotho),fibroblast growth factor23(FGF23),osteoprotectin(OPG)and hypoxia inducible factor-1α(HIF-1α)were detected by ELISA.All patients were evaluated for the presence of abdominal aortic calcification with a plain X-ray film of the abdomen.They were divided into a calcified group and a non-calcified group.The patients in the calcified group further improved the cardiac color Doppler ultrasound and cervical vascular ultrasound to evaluate their heart valve and carotid artery calcification situation respectively.According to the Kauppila scoring standard of abdominal aorta calcification and the segmentation method of the CORD study,the semi-quantitative scoring of abdominal aorta was performed,and the patients in the calcification group were further divided into mild calcification group(0 <AACS <5)and moderate to severe calcification group(AACS≥5)according to the abdominal aortic calcification score(AACS).Statistical analysis of the overall status and clinical characteristics of abdominal aortic calcification in patients with MHD,comparing the general clinical data,laboratory tests and serological cytokine levels between the calcification group and the non-calcification group,analysis of the correlation between abdominal aortic calcification score and the above indicators,and the binary classification Logistic Regression analysis was used to find the risk factors of vascular calcification and possible serological markers of vascular calcification.Results: 1.Among the 107 patients with MHD,42(39.25%)had abdominal aortic calcification,including 22(52.38%)with mild calcification,20(47.62%)with moderate to severe calcification,and 65(60.75%)without abdominal aortic calcification.Among the 42 patients with abdominal aortic calcification,31(73.81%)patients had heart valve or carotid calcification,including 1(2.38%)patient with heart valve calcification alone and 23(54.76%)patients with carotid artery calcification alone,and 7(16.67%)patients coexisted with the three.2.The age,BMI,total cholesterol,blood glucose,blood phosphorus,and calcium-phosphate product of the calcification group were higher than those of the non-calcification group,diastolic blood pressure and alkaline phosphatase were lower than those of the non-calcification group,differences were statistically significant(P<0.05),while gender,prevalence of diabetes,dialysis age,systolic blood pressure,pulse pressure difference,serum albumin,HDL-C,LDL-C,blood calcium,PTH,CRP and other indicators were not different between the two groups(P>0.05)).3.The serum BMP2 level in the calcified group was higher than that in the non-calcified group,and the difference was statistically significant(P<0.05),while the serum BMP4,BMP7,α-klotho,FGF23,OPG and HIF-1α levels were not statistically different between the two groups(P>0.05).4.Further comparison between the mild calcification group and the moderate to severe calcification group,there were no significant differences in general data,laboratory tests and serological cytokine levels between the two groups(P>0.05).5.Correlation analysis found that abdominal aortic calcification score was related to the age of MHD patients(r=0.267,P=0.006),total cholesterol(r=0.222,P=0.021),and LDL-C(r=0.244,P=0.011),blood phosphorus(r=0.251,P= 0.009),calcium-phosphorus product(r=0.279,P=0.004)were positively correlated,and negatively correlated with diastolic blood pressure(r=-0.232,P= 0.017),and there was no significant correlation with other general clinical indicators and serum levels of BMP2,BMP4,BMP7,α-klotho,FGF23,OPG and HIF-1α(P>0.05).6.Logistic regression analysis showed that age(OR=1.147,P<0.001),total cholesterol(OR=2.252,P=0.014),blood glucose(OR=1.29,P=0.009),blood phosphorus(OR=5.867,P=0.013)and serum BMP2 levels(OR=1.086,P=0.001)were independent risk factors for abdominal aortic calcification in patients with MHD.Conclusion: 1.The incidence of vascular calcification is high in patients with MHD,and it is often associated with calcification in multiple sites.2.Abdominal aortic calcification in patients with MHD is related to age,blood lipid,blood phosphorus,calcium-phosphate product,and diastolic pressure.Age,blood lipid,blood glucose,and blood phosphorus are risk factors for abdominal aortic calcification.3.Serum BMP2 levels in the calcified group of MHD patients are higher than those in the non-calcified group.Serum BMP2 is also a risk factor for the occurrence of abdominal aortic calcification,but its relationship with the progress and severity of abdominal aortic calcification needs further clarification.4.At present,no ideal non-invasive serum marker for judging the occurrence and degree of vascular calcification has been found,and the traditional imaging method is still more stable and practical.5.Regular detection of cardiovascular calcification in MHD patients and enhanced management of blood lipid,mineral metabolism disorders,blood glucose and nutritional status may delay the progression of vascular calcification and improve the prognosis of patients.