The Research On Serum Bilirubin Metabolism In Chronic Ranal Disease

Background As a common and epidemic disease, cardiovascular complication of chronic kidney disease has many causes still be ambiguous except some existed risk factors,such as smoking,obesity,hypertension and diabetes. Apart from these,it correlated with oxidative stress,micro-inflammatory, homocysteic acid. Bilirubin, which were once considered to be toxic metabolic waste products, have recently been shown to have dose-dependent vasodilatory, antioxidant, and anti-inflammatory properties.As an important endogenesis physiological antioxidant,serum bilirubin is being recognized step by step.Objective To study the association of serum bilirubin with risk factor such as oxidative stress,micro-inflammatory, homocysteic acid;to find out the relationship of serum bilirubin and non-traditionary risk factor such as oxidative stress,micro-inflammatory, homocysteic acid;to explore the new idea for prevention and therapy of CKD.Material and Methods 83 patients who correspond to CKD were included in the study and divided into five groups according to whether or not hemodialysis and glomerular filtration rate calculated.(1=the healthy control group,2=GFR lower grade-descented group,3=GFR medium-descented group,4=GFR severe-descented group,5=CRF without hemodialysis,6=CRF with disciplinary hemodialysis).Those with higher liver enzyme; with liver and gallbladder disease;or with hemblysis anemia and severe heart failure were all excluded.All the patients should have noted age,gender,GFR calculated and so on.After acute factor were retrieved serum total bilirubin(TBIL),direct bilirubin(DBIL),andindirectbilirubin(IBIL),alsototalcholesterol(TC),triglycerinate(TG),low density lipoprotein(LDL-C),high density lipoprotein(HDL-C),and total homocysteic acid(tHcy),C-reactive protein(CRP) et cetera were all tested in all patients and healthy control group.Statistical analysis comparison of serum bilirubin among groups were analyzed by t-test for indepent samples.The association of billirubin and other risk factors of CVD were analyzed by spearman correlation and multiple linear stepwise regression.Results The two-sample test for independent sample showed that the levels of TBIL in 5 group and 6 group are statistically significant lower than those in the healthy control(p <0.05),DBIL have no statistical significance,IBIL in 3,4,5,6 are statistically significant lower than those in the healthy control(p< 0.05, p<0.05, p<0.01,p< 0.01).The concentration of C-reactive protein in 3,4,5,6 are statistically significant lower than those in the control(p<0.05),the level of total homocysteic acid in 3,4,5,6 are statistically significant lower than those in the control(p<0.01).Spearman correlation reveal that TBIL have significantly negative with low-density lipoprotein cholesterol,β2-microglobulin, P,GROUP,C-reactive protein,homocysteic acid and positive with high density lipoprotein cholesterol, Ca,total protein,albumin,hemoglobin,age,DBIL have significantly negative with total protein,albumin,hemoglobin,age,IBIL have significantly negative with low-density lipoprotein cholesterol,β2-microglobulin, P,GROUP,C-reactive protein, homocysteic acid and positive with high density lipoprotein cholesterol,Ca,total protein, albumin,hemoglobin,age triglyeride. Multiple linear stepwise regression analysis showed that Hcy,TG,UA and HDL-ch all enter the following multiple linear stepwise regression equation:CRP=-1.333+0.151Hcy+1.446TG+0.005UA-1.777HDL-ch, R=0.659, R2=.434. And DBIL is related to both AL and age.The regression equation is DBIL=-.629+ 0.052AL+0.013age,R=0.343,R2=0.117. IBIL is related with AL,age and group,the equation is:IBIL=2.210+0.129AL-0.453age+0.034group.Conculsion In all patients serum bilirubin is significantly gradually depress following decreased GFR.Low serum bilirubin concentration is related with CRP, blood lipid and total homocysteic acid. Serum blirubin educe cytoprotection by inhibiting lipid oxidation,inflammatory and oxidative stress.Lower serum bilirubin and other known risk factors affected mutually,they all related to cardiovascular complication.By analyzing bilirubin concentration and other risk factors of cardiovascular complication,it may be helpful to estimate the severity of cardiovascular complication and make more reasonable therapy plans.Based on the protective role of bilirubin against cardiovascular complication,we may establish theory base and pioneer a new way for delaying failed renal function and therapy of cardiovascular complication in the future.