A Clinical Study Of The Relationship Between Serum Brain Natriuretic Peptide(BNP) Level And Cardiac Insufficiency In CAPD Patients

Objectives: The aims of this study was to investigate the relationship between serum brain natriuretic peptide (BNP) and cardiac insufficiency in CAPD patients. In order to probe the value of BNP in diagnosis and cardiac function measurement in CAPD patients with CHF.Methods: 1. This clinical study included 95 patients on CAPD and 20 healthy control subjects in Shanghai First People's Hospital. Serum BNP levels were measured in 95 CAPD patients (including 58 males and 37 females) and control subjects (including 11 males and 9 females). The patients's age are between the a 25 to 85 (mean 58.96±17.63) years old who had been on CAPD treatment for 3 months or more. The patients were divided into four groups by New York Heart Association (NYHA) cardiac function classifications. BNP levels were measured by ELISA method. LVEF, LVEED, LVESD, IVST and LAD were examined by ultrasound cardiography. Left ventricular mass index (LVMI) was calculated according to the Devereux formula.RESULTS: 1. CAPD Patients had higher values of BNP compared with control group were:(respectively 361.0(16.2～3670.0) vs 17.9(5.0～97.2)pg/ml, P<0.01). The levels of BNP in the normal control group were positively correlated with age (r= 0.642,p<0.05), Spearman correlation analysis did not show a significant correlation between BNP and sex , BMI, creatinine, smoking, MABP, cholesterol, triglyeride. BNP levels in female were a little exceed the male. 2. The levels in CAPD patients were skewness distribution data, were positively correlated with age (r= 0.487,p<0.01), and were negatively correlated with DBP,MABP (p<0.05). There are not a significant correlation between BNP and sex, body mass index(BMI), BSA, smoking, SBP, the type of primary disease. 3. CAPD patients's BNP concentrations in four groups respectively were 79.7(16.2 ~ 726.0) pg/ml, 279.7(40.9 ~ 1854.0) pg/ml, 1020.0(157.0 ~ 3400.0) pg/ml, 3215.0(2980.0 ~ 3400.0) pg/ml, There are a significant correlation between BNP and cardiac function grading. 4. The levels of BNP in CAPD patients were negatively correlated with LVEF(r= - 0.629,p<0.01); The levels of BNP in CAPD patients were positively correlated with the LVMI, LVESD, LVEDD, LAD and the cardiothoracic ratio. BNP levels did not correlate with IVST and LVPWT (p>0.05). 5. Serum BNP levels were negatively correlated with albumin, prealbumin, creatinine (p<0.05). 6. Stepwise regression analysis showed that LV ejection fraction (beta = -0.509, p < 0.01) , LVMI (beta = 0.375, p <0.05), albumin (beta = -0.195, p < 0.05) and cardiac functional grading(beta = 0.442, p <0.01) were independently associated with the serum BNP concentration. 5. The ROC curve of BNP diagnosing heart failure in CAPD patients had an AUC of 0.878, Using a cut-off value of 127.1pg/ml, the sensitivity, specificity of BNP diagnosis HF were 87.1% and 69.8%, respectively. And The ROC curve of BNP diagnosing LVH had an AUC of 0.737. Using a cut-off value of 174.0pg/ml, the sensitivity, specificity of BNP diagnosis LVH were 80.4% and 51.3 %, respectively.CONCLUSIONS: The detection of serum BNP maybe a very useful method for auxiliary diagnosis cardiac insufficiency and LVH in CAPD patients. it appears useful for reflecting left ventricular size and remodeling. The serum BNP concentration might be a useful clinical biomarker for evaluating heart function in CAPD patients.