慢性肾脏病患者血压晨峰、心率变异性与血管内皮损伤的相关性

Correlation between morning blood pressure surge,heart rate variability,and vascular endothelial damage in chronic kidney disease patients

目的探讨慢性肾脏病患者血压晨峰、心率变异性与血管内皮损伤的相关性,阐明慢性肾脏病血压改变的可能机制。方法采用前瞻性观察研究,选取2018年6月至2019年6月于江苏省人民医院溧阳分院肾内科就诊的慢性肾脏病患者70例,根据估算的肾小球滤过率(eGFR)分为肾功能轻度下降组(35例)和肾功能中重度下降组(35例),同时选择同期既往无慢性肾脏病且体检正常人群30例作为健康对照组。检测所有患者的血压晨峰、心率变异性[时域指标包括全部正常窦性心搏间期的标准差(SDNN)、每5分钟时段NN间期均值的标准差(SDANN)、全程相邻NN间期差值均方根(rMSSD)、24 h内相差>50 ms的相邻窦性心搏间期占窦性心搏间期总数的百分比(pNN50);频域指标包括低频功率(LF)、高频功率(HF)和LF/HF]、血管内皮损伤[血清内皮素1(ET-1)、血清一氧化氮(NO)]情况,采用方差分析进行组间比较。以起床后2 h平均血压与夜间最低血压在内的1 h平均血压差值≥35 mmHg(1 mmHg=0.133 kPa)定义为血压晨峰,将3组患者分别分为血压晨峰组和非血压晨峰组,比较各组心率变异性和血管内皮损伤情况。采用Pearson相关性检验分析慢性肾脏病患者血压晨峰与心率变异及血管内皮损伤的相关性。结果(1)肾功能轻度下降组患者的血压晨峰比例、LF、ET-1高于健康对照组,rMSSD、HF、LF/HF、NO水平低于健康对照组,差异均有统计学意义(P均<0.05);肾功能中重度下降组患者的血压晨峰比例、ET-1高于健康对照组和肾功能轻度下降组,pNN50、LF、LF/HF、NO水平低于健康对照组和肾功能轻度下降组,差异均有统计学意义(P均<0.05)。(2)健康对照组中,血压晨峰组患者SDNN、rMSSD、pNN50、HF、LF/HF、NO低于非血压晨峰组,LF、ET-1水平高于非血压晨峰组,差异均有统计学意义(P均<0.05);肾功能轻度下降组中,血压晨峰组患者pNN50、LF/HF、NO低于非血压晨峰组,ET-1水平高于非血压晨峰组,差异均有统计学意义(P均<0.05);肾功能中重度下降组中,血压晨峰组患者SDANN、LF、LF/HF、NO低于非血压晨峰组,ET-1水平高于非血压晨峰组,差异均有统计学意义(P均<0.05)。(3)慢性肾脏病患者血压晨峰与SDNN、SDANN、rMSSD、pNN50、LF、HF、LF/HF、NO呈负相关(P均<0.05),与ET-1呈正相关(P<0.05)。结论慢性肾脏病患者普遍存在血压晨峰、心率变异性和血管内皮损伤,且血压晨峰与心率变异、血管内皮损伤存在相关性。

ObjectiveTo investigate the relationship between morning blood pressure surge,heart rate variability,and vascular endothelial damage in chronic kidney disease(CKD)patients,in order to clarify the mechanism of blood pressure change in CKD.MethodsIn this prospective observational study,70 patients with CKD treated at Nephrology Department of Liyang Branch of Jiangsu Provincial People's Hospital were selected.According to estimated glomerular filtration rate(eGFR),the patients were divided into a mildly decreased renal function group(n=35),and a moderately to severely decreased renal function group(n=35).Meanwhile,30 healthy patients without CKD were selected as a normal control group.Morning peak blood pressure,heart rate variability[time domain indexes:standard deviation of normal-to-normal intervals(SDNN),standard deviation of averaged normal-to-normal intervals(SDANN),root of the mean square of successive differences(rMSSD),percentage of adjacent normal-to-normal intervals differing by>50 ms(pNN50);frequency domain indexes:low frequency(LF),high frequency(HF),and LF/HF],and vascular endothelial damage[serum endothelin-1(ET-1)and serum nitric oxide(NO)]were detected and compared among the three groups using one-way ANOVA.The morning peak blood pressure was defined as the 1 h mean blood pressure difference value≥35 mmHg(1 mmHg=0.133 kPa)between the mean blood pressure 2 h after getting up and the minimum blood pressure at night.Patients of the three groups were divided into a morning peak blood pressure subgroup and a non-morning peak blood pressure subgroup,respectively,and the heart rate variability and vascular endothelial damage of these two subgroups were compared.The correlation of morning blood pressure peak with heart rate variation and vascular endothelial damage was analyzed using Pearson correlation analysis.ResultsCompared with the normal control group,the proportion of patients with morning blood pressure surge,LF,and ET-1 significantly increased,but rMSSD,HF,LF/HF,and NO significantly decreased in the mildly decreased renal function group(P<0.05).Compared with the normal control group and mildly decreased renal function group,the proportion of patients with morning blood pressure surge and ET-1 significantly increased,but pNN50,LF,LF/HF,and NO significantly decreased in the moderately to severely decreased renal function group(P<0.05).In the normal control group,compared with the non-morning peak blood pressure subgroup,SDNN,rMSSD,pNN50,HF,LF/HF,and NO of morning peak blood pressure group significantly deceased,but LF and ET-1 significantly increased in the non-morning peak blood pressure subgroup(P<0.05).In the mildly decreased renal function group,compared with the non-morning peak blood pressure subgroup,pNN50,LF/HF,and NO significantly deceased,but ET-1 significantly increased in the non-morning peak blood pressure subgroup(P<0.05).In the moderately to severely decreased renal function group,compared with the non-morning peak blood pressure subgroup,SDANN,LF,LF/HF,and NO significantly deceased,but ET-1 significantly increased in the non-morning peak blood pressure subgroup(P<0.05).Among CKD patients,the morning blood pressure surge were negatively correlated with SDNN,SDANN,rMSSD,pNN50,LF,HF,LF/HF,and NO(P<0.05),and positively correlated with ET-1(P<0.05).ConclusionMorning blood pressure surge,heart rate variability,and vascular endothelial damage are common in patients with CKD,and there are correlations between morning blood pressure surge and heart rate variability and vascular endothelial damage in CKD patients.