Study On The Correlation Between Serum FGF23 And Renal Anemia In Maintenance Hemodialysis Patients

Objective:to analyze the association between the level of serum Fibroblast facto23（FGF 23）in maintenance hemodialysis（MHD）patients with renal anemia so as to providing a new method for diagnosising and treating renal anemia,delaying the progression of chronic kidney disease,reducing cardiovascular events and mortality of MHD patients.Methods:A total of 60patients who accepted maintenance hemodialysis treatment in outpatient and inpatient departments were selected from march to October 2016,while a total of 30 healthy patients in our Health examination center were selected.The clinical data of all selected patients including gender,age,hemodialysis vintage,primary disease,vascular access,frequency of dialysis,ultrafiltration,and weight before and after dialysis were collected.Blood specimens were collected and then checked in the clinical laboratory of our hospital.Anemia indexes included as follows:hemoglobin（HB）,hematocrit（HCT）,red blood cell count（RBC）,mean corpuscular volume（MCV）,mean corpuscular hemoglobin（MCH）,mean corpuscular hemoglobin concentration（MCHC）,and red blood cell volume distribution width（RDW）,Nutrtion indexes included albumin（ALB）,Renal function indexes included as follows:creatinine（Cr）,Urea nitrogen（BUN）before and after dialysis,Mineral metabolism indexes included as follows:calcium（Ca）,phosphorus（P）,parathyroid hormone（PTH）,Iron metabolism indexes included as follows:serum iron（SI）,serum ferrtin（SF）,total iron blinding capacity（TIBC）.Inflammatory markers included as follows:hypersensitive c-reactive protein（hsCRP）.According to instructions of kit,1,25hydroxy vitamin D3[1,25（OH）2 D3],FGF23,Hepcidinidin,total iron binding capacity（TIBC）,transferrin receptor（sTfR）were texted.According to the formula as follows:TS%=SI/TIBC*100%,spKt/V=-ln（R-0.008 x t）+（4-3.5 x R）*UF/W,the transferritin saturation（TS%）,single room urea scavenging index spKt/V were calculated.Statistical analysis was performed using SPSS 20.0.The measurement data which satisfied the normal distribution through K–S test and the skewness distribution which obeyed the normal distribution after logarithmic transformation were presented as mean±standard deviation（?x±s）,the correlation analysis was used by Pearson correlation analysis.For the data,which were normally distributed with equal variances,comparisons between the two groups were performed using independent sample t-tests;For the data,which were not normally distributed or had unequal variances,nonparametric group comparisons were performed using Mann-Whitney rank sum tests.counting datas were rspresented by rate or composition ratio,comparison between the two groups was used by the four table chi-square test.Multiple linear regression analysis was used to analyze the influencing factors.Inspection level isα=0.05.A P value of<0.05 was considered to be statistically significant.Results 1.there was no statistical difference in age and gender between the MHD group（group A）and the healthy control group（group B）,which indicated that the baseline level of the two groups is consistent and comparable.The remaining indicators between the two groups were obviously different.While the serological paramenters of Group B were within the normal range,in group A,a set of anemia indicators HB,HCT,RBC,MCV,MCH,MCHC,nutrtion indexes ALB,mineral metabolism indexes Ca,1,25（OH）₂ D₃,iron metabolism indexes SI,TS,TIBC were lower than those in group B,whereas renal function indexed BUN,Cr,iron metabolism indexes SF,Hepcidin,sTfR,mineral metabolism indexes FGF23,P,Ca*P,PTH,inflammatory markers hsCRP were significantly higher than those in group B.2.In group A,people with absolute iron deficiency was 21 cases（35 percent）,a total of 25 people（42 percent）was of functional iron deficiency,while people with normal iron metabolism accounted for 14cases（23%）.Distribution of anemia was as follows:There were 28 cases of mild anemia（46 percent）,31cases of moderate anemia（52 percent）and 1cases of severe anemia（2 percent）.The morphological classification was defined by MCV,MCH and MCHC.In this study,MCV,MCH and MCHC in MHD patients were lower than those in the healthy control group,so that microcytichypochromic anemia was the major type in MHD patients.In addition,Bassman proposed morphological classification in terms of MCV and RDW.In this study,the MCV was lower than that in the healthy control group,while the RDW was higher than that in the healthy control group,which was shown as the small cell nonhomogenous anemia.3.By Pearson linear correlation analysis showed that HB was positively correlated with MCH（r=0.772,P=0.000）,MCHC（r=0.804,P=0.000）,SI（r=0.256,P=0.048）,ALB（r=0.263,P=0.263）;and lnFGF23（r=-0.691,P=0.000）was inversely correlated with Hepc（r=0.514,P=0.514）,P（r=0.267,P=0.267）,ln（PTH）（r=0.279,P=0.279）and ln（hsCRP）（r=0.609,P=0.609）.There was no significant correlation with RBC,HCT,MCV,RDW,SF,TS,sTfR,1,25（OH）2D3,spKt/V,Ca,Ca*P,BUN,Cr and lnTIBC.By the Pearson correlation analysis,lnFGF23 was positively correlated with the mineral metabolism indexes as follows:P（r=0.498,P=0.498）,Ca*P（r=0.278,P=0.032）,ln（PTH）（r=0.318,P=0.318）,iron metabolism indexes as follows:Hepcidin（r=0.567,P=0.567）and ln（hs CRP）which is one of the inflammation indexes（r=0.810,P=0.810）;whereas there were inversely correlated with the anemia indicators as follows:HB（r=0.691,P=0.691）,MCH（r=0.594,P=0.594）,MCHC（r=0.556,P=0.556）,iron metabolism indexes as follows:SI（r=0.368,P=0.368）,lnTIBC（r=0.303,P=0.303）;There was no significant correlation between lnFGF23 and HCT,RBC,MCV,RDW,ALB,BUN,Cr,Ca,1,25（OH）2D3,SF,TS%,sTfR,spKt/V.4.It was found that the ln（hsCRP）,HB and P were independent factors of FGF23.The degree of influence is that ln（hsCRP）>HB>P,in whith hsCRP,P and FGF23 are independent positive correlation,while HB is independent negative correlation with FGF23.Conclusions:1.There was a significant correlation between renal anemia and nutritional status,iron metabolism disorder,mineral metabolic disorders and inflammation.Among them,FGF23 may participate in renal anemia by affecting iron metabolism and inflammation.2.FGF23 was regulated by various factors including mineral metabolism disorder,iron metabolism,inflammation and erythrocyte production.3.As we all know,the effect of phosphorus accumulation on FGF23 was far-reaching.Besides that,erythrocyte formation and inflammation were independently associated with increased FGF23 in plasma levels.