腹内脂肪堆积对高血压患者心脏自主神经功能的影响

摘要

目的 探讨腹内脂肪堆积与心率变异性(HRV)的关系.方法 选择第三军医大学大坪医院2009年5月—2010年5月收治的353例高血压患者作为研究对象,其中男197例,女156例,年龄27～85(55±13)岁.353例患者均行腹部脂肪超声及24h动态心电图监测,根据腹内脂肪超声厚度(男性≥38.5mm,女性≥34.7mm)将患者分为腹内脂肪堆积组和腹内脂肪正常组,并根据腹内脂肪厚度四分位值分为4组,比较各组间HRV的差异.结果 24h动态心电图时域指标比较显示,腹内脂肪堆积组中反映总神经张力的全部窦性RR间期标准差(SDNN)、反映交感神经张力的每5min内RR间期平均值标准差(SDANN)、反映迷走神经张力的相邻RR间期差的均方根(RMSSD)、NN间期标准差的平均值(SDNN index)均明显低于腹内脂肪正常组(P＜0.05).四分位法分层分析显示,腹内脂肪厚度＞38.0mm组相邻RR间期差值超过50ms的心搏数占总心搏数的百分比(PNN50)及SDNN、SDANN、RMSSD、SDNN index均显著低于＜15.5mm组,PNN50、SDNN、SDANN、RMSSD显著低于腹内脂肪厚度15.6～27.0mm组,而腹内脂肪厚度27.1～ 38.0mm组SDNN、SDNN index显著低于腹内脂肪厚度＜15.5mm组,SDNN显著低于腹内脂肪厚度15.6～27.0mm组(P＜0.05).线性回归分析显示,腹内脂肪厚度、空腹血糖、性别为SDNN的主要影响因素；腹内脂肪厚度、性别为SDANN的主要影响因素；腹内脂肪厚度、空腹血糖、舒张压为SDNN index的主要影响因素.结论 腹内脂肪堆积可显著降低高血压患者HRV.%Objective To explore the relationship between intra-abdominal fat accumulation and heart rate variability. Methods A total of 353 patients with hypertension were enrolled in this study, among them there were 197 males and 156 females, aged from 27 to 85 years old with a mean of 55 ± 13 years. All the patients received abdominal fat ultrasonography, 24-hour ambulatory ECG and blood biochemical tests, and they were divided into intra-abdominal fat accumulation group and normal intra-abdominal fat group according to the fat thickness measured by B-mode ultrasound value (male ≥ 38.5mm, female ≥ 34.7mm). They were redivided into four subgroups based on interquartile range of the fat thickness for comparing the difference in heart rate variability between 4 groups. Results Each subject had a 24-hour ECG recording taken and the standard HRV time-domain indices: SDNN (standard deviation of the normal-to-normal RR. Intervals), reflecting total nervous tension, SDANN (standard deviation of the averages of RR intervals in all 5-minute segments), reflecting sympathetic tone, and RMSSD (the root mean square successive differences) and SDNN index (mean of the standard deviations of RR intervals in all S-minute segments), reflecting vagal nerve tone were determined. Results showed all the aforesaid indices were lower in the intra-abdominal fat group than in the normal intra-abdominal fat group (P<0.05). Hierarchical analysis by interquartile revealed that PNN50 (the percentage of successive RR intervals that differed by more than 50ms), SDNN, SDANN, RMSSD and SDNN index were significantly lower in abdominal fat thickness >38.0mm group than in <15.5mm group (P<0.0S): PNN50, SDNNN, SDANN and RMSSD were significantly lower in the >38.0mm group than in 15.6-27.0mm group: SDNN and SDNN index were significantly lower in the 27.1-38.0mm group than in <15.5mm group: SDNN was significantly lower in the 27.1-38.0mm group than in 15.6-27.0mm group. Linear regressionrnCr showed no change in the four groups (P>0.05). Conclusion Safe limit of in tra-abdominal pressures is less than l0mmHg, and intra-abdominal pressure of 1 5mmHg should be avoided in spontaneously breathing anesthetized rats.