Pelat M, Verwaerde P, Lazartiques E, Cabrol P, Galitzky J, Berlan M, Montastruc J L, Senard J M
Laboratoire de pharmacologie médicale et clinique, INSERM U317, Faculté de médecine, Toulouse.
Arch Mal Coeur Vaiss. 1998 Aug;91(8):999-1002.
Modifications of heart rate (HR) and systolic blood pressure (SBP) variabilities (V) have been reported in the human syndrome arterial hypertension plus insulin-resistance. The aim of this study was to characterize the 24 h SBPV and HRV in both time and frequency domains during weight increase in dogs fed ad libitum with a high fat diet. Implantable transmitter units for measurement of blood pressure and heart rate were surgically implanted in five beagle male dogs. BP and HR were continuously recorded using telemetric measurements during 24 hours, before and after 6 and 9 weeks of hypercaloric diet in quiet animals submitted to a 12h light-dark cycle. To study nychtemeral cycle of SBP and HR, two periods were chosen: day (from 6.00 h to 19.00 h) and night (from 23.00 h to 6.00 h). Spontaneous baroreflex efficiency was measured using the sequence method. Spectral variability of HR and SBP was analyzed using a fast Fourier transformation on 512 consecutive values and normalized units of low (LF: 50-150 mHz, reflecting sympathetic activity) and high (HF: respiratory rate +/- 50 mHz, reflecting parasympathetic activity) frequency bands were calculated. The energy of total spectrum (from 0.004 to 1 Hz) was also studied. Body weight (12.4 +/- 0.9 vs 14.9 +/- 0.9 kg, p < 0.05). SBP (132 +/- 1 vs 147 +/- 1 mmHg, p < 0.05) significantly increased after 9 weeks of hypercaloric diet. A nycthemeral HR rhythm was present at baseline (day: 79 +/- 1 vs night: 71 +/- 1 bpm) but not after 9 weeks (day: 91 +/- 4 bpm ; night: 86 +/- 2 bpm). Concomitantly, the efficiency of spontaneous baroreflex decreased at 6 weeks (36 +/- 1 vs 42 +/- 2 mmHg/ms, p < 0.05). A significant decrease in HF energy of HRV was found after 6 but not after 9 weeks. LF energy of SBPV was increased at 6 but not at 9 weeks (table). [table: see text] In conclusion, this study shows that an hyperlipidic and hypercaloric diet induces transient variations in autonomic nervous system activity which could be the physiopathological link between obesity, insulin-resistance and arterial hypertension.
据报道，人类动脉高血压合并胰岛素抵抗综合征中心率（HR）和收缩压（SBP）变异性（V）会发生改变。本研究的目的是在自由采食高脂饮食的犬体重增加期间，从时域和频域两方面对其24小时SBPV和HRV进行特征描述。将用于测量血压和心率的可植入式发射器单元通过手术植入5只雄性比格犬体内。在安静的、处于12小时明暗循环的动物中，在高热量饮食6周和9周之前及之后，使用遥测测量法连续24小时记录血压和心率。为研究SBP和HR的昼夜循环，选取了两个时间段：白天（6:00至19:00）和夜间（23:00至6:00）。使用序列法测量自发性压力反射效率。对HR和SBP的频谱变异性进行分析，对512个连续值进行快速傅里叶变换，并计算低频（LF：50 - 150 mHz，反映交感神经活动）和高频（HF：呼吸频率±50 mHz，反映副交感神经活动）频段的标准化单位。还研究了总频谱（0.004至1 Hz）的能量。高热量饮食9周后体重显著增加（12.4±0.9 vs 14.9±0.9 kg，p < 0.05），收缩压也显著升高（132±1 vs
147±1 mmHg，p < 0.05）。基线时存在昼夜HR节律（白天：79±1 vs 夜间：71±1次/分钟），但9周后不存在（白天：91±4次/分钟；夜间：86±2次/分钟）。同时，自发性压力反射效率在6周时降低（36±1 vs 42±2 mmHg/ms，p < 0.05）。HRV的HF能量在6周后显著降低，但9周后未降低。SBPV的LF能量在6周时增加，但9周时未增加（见表）。[表：见正文]总之，本研究表明高脂高热量饮食会引起自主神经系统活动的短暂变化，这可能是肥胖、胰岛素抵抗和动脉高血压之间的生理病理联系。
