The Relationship Between Serum DMP1 And Mineral Metabolism And Bone Mineral Density In MHD Patients

Objective:To investigate the relationship between serum dentin matrix protein 1(DMP1)and mineral metabolism and bone density in maintenance hemodialysis(MHD)patients.Methods:Ninety-five MHD patients who received hemodialysis treatment in blood Purification Center of Qingdao Municipal Hospital from July 2019 to July 2020 were selected as the research subjects.We collected the clinical data and serum samples of the subjects and tested the serum DMP1 level by ELISA.MHD patient’s femoral neck bone mineral density(BMD)was tested by dual-energy X-ray absorptiometry,the results were expressed as BMD T value.The serum DMP1 levels of 50 healthy volunteers who underwent physical examination in the hospital during the same period were detected,and the serum DMP1 levels of MHD patients and healthy people were compared.MHD patients were divided into the high DMP1 group and the low DMP1 group based on the median concentration of serum DMP1.Clinical and laboratory indicators were analyzed and compared among the two groups.The influencing factors of MHD patient’s serum DMP1 level was analyzed by spearman correlation analysis and multiple linear regression.The influencing factors of low bone mineral density in MHD patients was analyzed by logistic regression.Results:1.The serum DMP1 level in MHD patients [21.55(16.37,24.83)ng/ d L] was lower than that in healthy volunteers [25.89(19.29,34.23)ng/ d L],and the difference was statistically significant(P=0.001).2.estimated glomerular filtration rate(eGFR),parathyroid hormone(PTH),and T value of femoral neck bone density in patients with low DMP1 group were higher than those with high DMP1 group,with statistically significant differences(P values were 0.014,0.002,0.001,respectively).The low DMP1 group had a higher age and dialysis age than the high DMP1 group,with statistically significant differences(P values were 0.031 and 0.024,respectively).3.Spearman correlation analysis indicated that the serum DMP1 level of MHD patients was negatively correlated with age and dialysis age,and positively correlated with eGFR,PTH and T value of femoral neck bone mineral density(R value were-0.226,-0.223,0.210,0.294,0.370,respectively;P values were 0.028,0.030,0.041,0.004,<0.001,respectively).Multiple linear regression analysis indicated that PTH and T value were the independent influencing factors of serum DMP1 level in MHD patients(β value were 0.211,0.399,respectively;P values were 0.032 and 0.001,respectively).4.Logistic regression analysis indicated that high serum DMP1 level was an independent protective factor of low bone mineral density in MHD patients [OR value =0.913,95%CI(0.845,0.986),P=0.02],when removed the influence of confounding factors such as age,dialysis age,albumin,alkaline phosphatase and serum calcium.Conclusion:1.The serum DMP1 level in MHD patients was lower than that in the normal population.2.The age,dialysis age,eGFR,PTH and femoral neck BMD of MHD patients can influence their serum DMP1 levels.Among them,PTH and femoral neck BMD were independent influencing factors of serum DMP1 level in MHD patients.3.High serum DMP1 level is an independent protective factor for low bone mineral density in MHD patients.