容量负荷与慢性肾脏病患者合并高血压的相关性

Relationship Between Volume Load and Hypertension in Chronic Kidney Disease Patients

目的以慢性肾脏病(CKD)合并高血压患者为研究对象,通过生物电阻抗分析(BIA)方法测定容量,观察容量负荷与血压的关系。方法横断面研究纳入2006-2008年在北医三院肾内科门诊随诊的肾功能3～5期CKD病人301例,用BIA方法测定身高标化的细胞外容量(nECW),以反映CKD患者的容量负荷。分别计算男性、女性的nECW均值,将高于均值者定义为容量超负荷,将低于均值者定义为正常容量。结果 3、4、5期容量超负荷患者所占比例分别为38.6%,52.9%,54.0%(P<0.05);收缩压、脉压与nECW呈弱正相关(r=0.22,r=0.15,P<0.01)。容量超负荷CKD患者138例中,13例(9.4%)出现水肿,4例(2.9%)应用利尿剂。对单纯收缩期高血压(ISH)进行多因素回归分析显示,ISH发生的危险因素为年龄≥65岁、CKD5期、女性nECW>8.44L/m或男性nECW>10.66L/m。结论 38%～54%的CKD3～5期患者存在容量超负荷,并随着肾功能的进展,容量超负荷逐渐加重。容量负荷与收缩压和脉压密切相关,但容量超负荷的CKD患者仅少部分出现水肿和使用了利尿剂。单纯收缩压升高的危险因素是老年、严重肾功能受损、容量超负荷。

Objective To investigate the relationship between volume load measured by bioelectrical impedance analysis （BIA） and blood pressure in chronic kidney disease（CKD） patients.Methods Three hundred and one CKD patients were enrolled to this study.Volume load was assessed by normalized extracellular water by body height （nECW）,ratio of extracellular water to intracellular water （E/I）,ratio of extracellular water and total body water （E/T） by BIA methods.The mean value of nECW in both genders was arbitrarily set to define NV（lower than mean value） or HV status （higher than mean value）.Results The percentage of volume overload in CKD patients was 38.6% for stage 3,52.9% for stage 4 and 54.0% for stage 5;volume overload increased with a deterioration of renal function （P0.05）.Systolic blood pressure and pulse pressure were positively correlated with nECW （r=0.22,r=0.15,both P0.01）.There were only 4 cases （2.9%） treated with diuretics in the 138 HV cases.Logistic regression showed that age≥65 year-old,CKD stage 5 and nECW≥8.44 L/m（female） or nECW≥10.66 L/m （male） were independent predictors for isolated systolic hypertension（ISH）.Conclusion 38%-54% of the CKD stage 3-5 patients present volume overload and their volume progresses with a decreasing renal function.Volume load is positively correlated with systolic blood pressure and pulse pressure,but only a few patients with volume overload had edema and received diuretics.