RESUMO
objective To investigate the value of NT-proBNP in assessing the volume status in maintenance hemodialysis patients with non-dominant edema.Methods One hundred and forty-five patients were recruited.Bioimpedance measurements were performed for overhydration (OH).NT-proBNP was detected by colloidal gold method.Patients were divided into three groups by levels of OH variability (△ OH,equal to OH minus weight increase) as group H (hypervolemia,n=90); group N (normovolemia,n=36) and group L (hypovolemia,n=19).Hemoglobin,albumin,blood urea nitrogen and serum creatinine were assayed,blood pressure and body mass increase were recorded.Dry weight of patients in Group H were adjusted in 3 months,the relationship between NT-proBNP and volume change were assessed.Results (1) At baseline,overall plasma NT-proBNP levels were higher than normal range.The median NT-proBNP levels in group H and group N were [1318.50(IQR 717.00,3154.25) pg/ml] and [703.50 (IQR 873.00,450.50) pg/ml],respectively.NT-proBNP was positively correlated with △OH value (r=0.801,P ＜ 0.001).(2) After 3 months,NT-proBNP levels in group H was significantly lower than baseline.Forty-one patients reached normal volume range (group H1),49 patients were resistant hypervolemia (group H2).The median NT-proBNP levels in group H1 and group H2 were [685.00 (IQR 422.50,988.50) pg/ml] and [1569.00 (IQR 982.50,2500.50) pg/ml],△ OH in group H1 and group H2 were [(0.63±0.23)L] and [(1.75±0.71)L],respectively.NT-proBNP and △ OH value in two groups had significant difference (P ＜ 0.05).NT-proBNP was positively correlated with △ OH value (r=0.684,P ＜ 0.001).(3) The area under ROC curve for NT-proBNP was 0.818,95％CI (0.733～ 0.904),P ＜ 0.001,since the absolute value of normovolemia was defined as ≤ 1.The cut off value of plasma NT-proBNP was set at 962.50 pg/ml in MHD patients with non-dominant edema,the diagnostic specificity and sensitivity were 79.6％ and 73.2％.Conclusion NT-proBNP could be used to assess volume status in MHD patients with non dominant edema.