Correlation Between Serum Dephosphorylated Uncarboxylated Matrix Gla Protein And Vitamin K2 Levels And Vascular Calcification In Patients With Maintenance Hemodialysis

Objective To investigate the correlation between serum dephosphorylated uncarboxylated matrix Gla protein（dp-uc MGP）and vitamin K2 levels and vascular calcification（VC）in patients with maintenance hemodialysis（MHD）.Methods A total of 98 MHD patients admitted to the First Affiliated Hospital of Bengbu Medical College from November 2020 to July 2021 and 70 healthy people with matched age,gender and body mass index（BMI）were recruited as the research subjects,levels of serum dp-uc MGP and vitamin K2 were measured by enzyme linked immunosorbent assay（ELISA）.Carotid artery and abdominal aorta calcification were detected by color Doppler ultrasound and lateral abdominal X-ray,and the related factors affecting vascular calcification in MHD patients were analyzed.Meanwhile,the levels of serum dp-uc MGP and vitamin K2 in patients with different degrees of vascular calcification were compared,and the correlation between dp-uc MGP,vitamin K2 and vascular calcification was analyzed.Results Serum dp-uc MGP increased（Z=-7.767,P<0.001）and vitamin K2 decreased（t=16.006,P<0.001）in experimental group as compared with those in control group.In MHD patients with VC,parathyroid hormone（PTH）,alkaline phosphatase（ALP）,dp-uc MGP and age were higher than those without VC（In the carotid artery group:Z=-2.231,-2.831,-5.739 and-4.130 respectively,P=0.026,0.005,<0.001 and<0.001 respectively.In the abdominal aorta group:Z=-2.299,-3.415,-4.637 and-3.317respectively,P=0.022,0.001,<0.001 and 0.001 respectively）,while serum vitamin K2was lower than those without VC（In the carotid artery group:Z=-3.936,P<0.001.In the abdominal aorta group:t=5.423,P<0.001）.Logistic regression analysis showed that age,dp-uc MGP and vitamin K2 were the independent risk factors for vascular calcification in MHD patients（In the carotid artery group:OR=1.080,4.777 and 0.160respectively,95%CI=1.022～1.142,2.125～10.740 and 0.035～0.733 respectively,P=0.006,<0.001 and 0.018 respectively.In the abdominal aorta group:OR=1.066,2.259 and 0.104 respectively,95%CI=1.012～1.123,1.182～4.317 and 0.023～0.466respectively,P=0.016,0.014 and 0.003 respectively）.Correlation analysis showed that serum dp-uc MGP was positively correlated with PTH,ALP and age（r_s=0.684,0.620and 0.278 respectively,P<0.001,<0.001 and=0.006 respectively）,and negatively correlated with vitamin K2（r_s=-0.271,P=0.007）.Serum dp-uc MGP was higher in MHD patients with severe VC than in those with mild and moderate VC,while serum vitamin K2 was lower in MHD patients with severe VC than in those with mild VC（F=12.378and 4.478,P<0.001 and=0.017）.Conclusion 1.The level of serum dp-uc MGP in patients with MHD is higher than that in control group,while vitamin K2 is lower than that in control group.2.Age,serum dp-uc MGP and vitamin K2 in patients with MHD are correlated with vascular calcification.Age,high level of dp-uc MGP and low level of vitamin K2 may be independent risk factors for vascular calcification.3.Serum dp-uc MGP is positively correlated with PTH,ALP and age,and negatively correlated with vitamin K2 in patients with MHD.