Kapidžić Ana, Platiša Mirjana M, Bojić Tijana, Kalauzi Aleksandar
Institute of Biophysics, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
Institute of Biophysics, Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
Med Eng Phys. 2014 Dec;36(12):1577-84. doi: 10.1016/j.medengphy.2014.08.007. Epub 2014 Sep 4.
We examined the effects of gender and age in young and middle-aged subjects on the level of cardio-respiratory interaction by analyzing properties of cardiac, respiratory and cardiac-respiratory regulatory mechanisms under paced breathing. In 56 healthy subjects, ECG (RR interval) and respiratory signal were simultaneously acquired in supine position at paced (0.1-0.45 Hz, steps of 0.05 Hz) and spontaneous breathing. The participants were divided into gender matched group of young adults (19-25 years old) and middle-aged adults (35-44 years old). Power spectral analysis was applied on RR interval time series and spectral components in very low frequency (VLF), low frequency (LF) and high frequency (HF) ranges were computed. We also calculated sample entropy of RR interval series (SampEnRR), respiratory series (SampEnResp), and their cross-sample entropy (cross-SampEn). Under paced breathing, reduction of all spectral powers with age (p<0.05) is not gender dependent but reduction of some entropy measures is; SampEnRR and SampEnResp were lower only in men (p<0.05). In the middle-aged subjects, effect of gender on spectral measures is significant; males had lower HF (p < 0.05). Pattern of dependencies of SampEn and cross-SampEn on paced breathing frequency were significantly different in men (young vs. middle-aged, p = 0.001 and p = 0.037) and in middle-aged subjects (females vs. males, p = 0.011 and p = 0.008). In middle-aged males, lower entropy measures indicated reduced and less complex partial cardiac and respiratory control, and central cardio-respiratory control. In conclusion, in healthy middle-aged subjects changes in cardio-respiratory coupling are detectable only in males.
我们通过分析在定频呼吸下心脏、呼吸及心脏 - 呼吸调节机制的特性，研究了青年和中年受试者的性别及年龄对心肺相互作用水平的影响。在56名健康受试者中，于仰卧位在定频（0.1 - 0.45Hz，步长0.05Hz）和自主呼吸状态下同时采集心电图（RR间期）和呼吸信号。参与者被分为年龄匹配的青年组（19 - 25岁）和中年组（35 - 44岁）。对RR间期时间序列进行功率谱分析，并计算极低频（VLF）、低频（LF）和高频（HF）范围内的频谱成分。我们还计算了RR间期序列的样本熵（SampEnRR）、呼吸序列的样本熵（SampEnResp）及其交叉样本熵（cross - SampEn）。在定频呼吸下，所有频谱功率随年龄降低（p < 0.05），且与性别无关，但一些熵指标的降低与性别有关；SampEnRR和SampEnResp仅在男性中较低（p < 0.05）。在中年受试者中，性别对频谱指标的影响显著；男性的HF较低（p < 0.05）。SampEn和cross - SampEn对定频呼吸频率的依赖模式在男性（青年与中年，p = 0.001和p = 0.037）和中年受试者（女性与男性，p = 0.011和p = 0.008）中存在显著差异。在中年男性中，较低的熵指标表明心脏和呼吸的部分控制以及中枢心肺控制减弱且复杂性降低。总之，在健康中年受试者中，仅在男性中可检测到心肺耦合的变化。
