血液透析患者脑钠肽水平与左心功能不全及血容量负荷的关系

目的通过对维持性血液透析(maintain hemodialysis,MHD)患者透析前、后血清脑钠肽(brainnatriuretic peptide,BNP)的变化及其与左心室结构和功能以及血压、超滤量的相关性分析,探讨BNP在MHD患者血容量负荷评估中的临床应用价值。方法选择在上海市闸北区中心医院血液净化中心透析龄超过3个月的MHD患者56例,病情稳定,已排除急性心血管事件,分别检测患者一周连续3次治疗的透析前、后血清BNP水平,记录透析前、后血压的变化和透析超滤量(UF),同时应用心脏超声心动图测定患者一周连续3次透析前、后的左心房内径(LAD)、左心室舒张末内径(LVDd)、左心室收缩末内径(LVDs)、室间隔厚度(IVST)、左心室后壁厚度(LVPWT)、左心室射血分数(LVEF)等,计算左心室心肌重量指数(LVMI),探讨BNP与MHD患者左心室结构、功能和血容量的关系。结果①MHD患者透析前、后血清BNP水平均显著高于健康对照组,二者差异有统计学意义(P0.01),MHD患者透析后BNP水平较透析前下降(P0.01);MHD伴有高血压患者透析前的BNP水平较不伴有高血压患者显著升高(P0.01),伴有高血压的患者透析后BNP水平较透析前显著下降(P0.01);MHD不伴有高血压患者中,UF≥1.0kg的患者透析前BNP水平较UF1.0kg的患者显著升高(P0.01),UF≥1.0kg的患者透析后BNP水平较透析前显著下降(P0.05)。②MHD患者血清BNP分别与LVDd、LVDs、LVPWT、LVMI呈正相关(P0.05)、与LVEF呈负相关(P0.05)、与LAD、IVST无相关性,与血压、UF呈正相关(P0.05)。多因素回归分析显示,BNP、血压和年龄是MHD患者左心功能不全的独立危险因素。结论 MHD患者BNP水平普遍升高,并且与左心室功能及血容量负荷密切相关,是一个无创和灵敏的指标。测定血清BNP水平可有助于及时调整干体质量,减轻心脏负荷,减少心血管并发症,具有临床应用价值。

Relationship between brain natriuretic peptide,left heart failure and blood volume status in chronic kidney disease

Objective To investigate the serum levels of brain natriuretic peptide （BNP） before and after dialysis, and to explore its correlation with left ventricular function and volume overload in patients on maintenance hemodialysis （MHD）. Methods We recruited 56 patients who were treated with MHD for at least 3 months before the study and were in a stable clinic status without signs of cardiovascular disease. Serum BNP level was assayed by chemiluminescence. Body weight and blood pressure were recorded before and after dialysis. Left ventricular diameter （LVD）, left atrial diameter （LAD）, left ventricular posterior wall thickness （LVPWT）, interventricular septal thickness （IVST） and left ventricular ejection fraction （LVEF） were evaluated by ultrasonic cardiography. Blood samples were collected at the start and end of a dialysis session for 3 consecutive HD sessions. The relationship between serum BNP level and left heart failure in these patients was analyzed by logistic regression model. Results In MHD patients, the pre-and post-dialysis serum BNP levels were significantly higher than those of control group （P〈0.01）, and the values declined after each dialysis session. BNP levels gradually declined irrespective of changes in body weight and blood pressure. Serum BNP level was positively correlated with the levels of LVDd, LVDs, LVPWT and LVMI （P〈0.05）, and was negative correlated with the level of LVEF （P〈0.05）. Conclusion Higher serum BNP was frequently seen in MHD patient, and was closely related with the dilated left ventricle, poor cardiac function and volume overload. Serum BNP level may be used as a biochemical marker for evaluation of volume overload in MHD patient.