Evaluation Of Early Stage Renal Injury And Relative Biomarkers And Correlation Analysis Of Early Stage Of Heart And Renal Injury In Chronic Hypoxia

OBJECTIVE To study and evaluate the early stage renal injury and it’s relative biomarkers in the chronic hypoxia, as well as the early stage of cardiac and renal injury and their relationship in the COPD.METHODS We prospectively analyzed60patients with COPD as COPD group and53normal people as control group.The COPD group was further distributed into three groups according to hypoxia levels:mild hypoxia group (60mmHg<SPO2<85mmHg), medium hypoxia group (40mmHg<SPO2<60mmHg), and severe hypoxia group (SPO2<40mmHg); and into two groups according to pulmonary arterial pressure levels (with or without pulmonary hypertension groups).Routine renal function and laboratory markers of kidney injury were detected from blood, which include blood urine nitrogen (BUN), serum creatinine (Scr),retinol binding protein(RBP),beta2-microglobulin (β2-MG), Cystatin C (CysC), and estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI formula; the LVEF, LVEDD, valvular regurgitation was measured from UCG.RESULTS The levels of serum CysC,β2-MG, and the eGFR in COPD group were significantly changed (compared with them in the control group)(P<0.05). But the serum Scr, BUN, RBP were no significant differences between COPD and control groups.Further comparing the subgroups to control group,The eGFR in the medium and severe hypoxia groups were significant lower than it in the control group (P<0.05). There were no significant different among mild, medium and severe hypoxia groups. The levels of serum CysC and β2-MG were significantly higher in the three hypoxia groups (vs control group, p<0.05). The increased percentage in COPD group are42.67%and45%respectively. There is a highest percentage in the severe hypoxia groups (vs mild and medium hypoxia groups, p<0.05). The same results showed in pulmonary hypertension group and no pulmonary hypertension groups.β2-MG was positively correlated with CRP (P<0.05). Furthermore, In the analysis of UCG, the diastolic function injury was61.6%, the myocardial ischemia was30%; Mitral,tricuspid, pulmonary valve, aortic regurgitation were51.66%,66.66%,68.33%,45.00%, respectively. In the Pearson correlation analysis,β2-MG and CysC was negatively correlated with PO2and eGFR in COPD group; There were correlations between LVEF and eGFR、β-MG, CysC, Scr,(P<0.001) and between eGFR and LVEDD (P<0.05)CONCLUSION Chronic hypoxia contributes to the eraly stage of renal function injury and the eraly stage of heart and renal injury simultaneously in COPD. Concentrations of CysC and β2-MG. are related to eGFR and degree of hypoxia. The serum CysC,β2-MG, eGFR are the valuable biomarkers which can predict the early stage renal injury in chronic hypoxia. But β2-MG was positively correlated with CRP (P<0.05), among them, the serum CysC is more sensitive. The LVEF, LVEDDplay an important role to indicate the early stage heat injury.