Rabbia Franco, Silke Bernard, Conterno Andrea, Grosso Tiziana, De Vito Barbara, Rabbone Ivana, Chiandussi Livio, Veglio Franco
Hypertension Unit, S. Vito Hospital, University of Turin, Italy.
Obes Res. 2003 Apr;11(4):541-8. doi: 10.1038/oby.2003.76.
To investigate the cardiovascular autonomic function in pediatric obesity of different duration by using standard time domain, spectral heart rate variability (HRV), and nonlinear methods.
Fifty obese children (13.9 +/- 1.7 years) were compared with 12 lean subjects (12.9 +/- 1.6 years). Obese children were classified as recent obese (ROB) (<4 years), intermediate obese (IOB) (4 to 7 years), and long-term obese (OB) (>7 years). In all participants, we performed blood pressure (BP) measurements, laboratory tests, and 24-hour electrocardiogram/ambulatory BP monitoring. The spectral power was quantified in total power, very low-frequency (LF) power, high-frequency (HF) power, and LF to HF ratio. Total, long-term, and short-term time domain HRV were calculated. Poincaré plot and quadrant methods were used as nonlinear techniques.
All obese groups had higher casual and ambulatory BP and higher glucose, homeostasis model assessment, and triglyceride levels. All parameters reflecting parasympathetic tone (HF band, root mean square successive difference, proportion of successive normal-to-normal intervals, and scatterplot width) were significantly and persistently reduced in all obese groups in comparison with lean controls. LF normalized units, LF/HF, and cardiac acceleration (reflecting sympathetic activation) were significantly increased in the ROB group. In IOB and OB groups, LF, but not nonlinear, measures were similar to lean controls, suggesting biphasic behavior of sympathetic tone, whereas nonlinear analysis showed a decreasing trend with the duration of obesity. Long-term HRV measures were significantly reduced in ROB and IOB.
Autonomic nervous system changes in adolescent obesity seem to be related to its duration. Nonlinear methods of scatterplot and quadrant analysis permit assessment of autonomic balance, despite measuring different aspects of HRV.
采用标准时域、心率变异性（HRV）频谱分析及非线性方法，研究不同病程小儿肥胖症患者的心血管自主神经功能。
将50例肥胖儿童（13.9±1.7岁）与12例瘦儿童（12.9±1.6岁）进行比较。肥胖儿童分为近期肥胖（ROB）组（<4年）、中度肥胖（IOB）组（4至7年）和长期肥胖（OB）组（>7年）。对所有参与者进行血压（BP）测量、实验室检查及24小时心电图/动态血压监测。对总功率、极低频（LF）功率、高频（HF）功率及LF与HF比值进行频谱功率定量分析。计算总时域、长期时域及短时域HRV。采用庞加莱图和象限分析法作为非线性技术。
所有肥胖组的偶测血压和动态血压均较高，血糖、稳态模型评估及甘油三酯水平也较高。与瘦对照组相比，所有肥胖组中反映副交感神经张力的所有参数（HF频段、逐次差值均方根、正常到正常间期的比例及散点图宽度）均显著且持续降低。ROB组中LF标准化单位、LF/HF及心脏加速度（反映交感神经激活）显著升高。在IOB组和OB组中，LF测量值（而非非线性测量值）与瘦对照组相似，提示交感神经张力呈双相变化，而非线性分析显示其随肥胖病程呈下降趋势。ROB组和IOB组的长期HRV测量值显著降低。
青少年肥胖症患者的自主神经系统变化似乎与其病程有关。散点图和象限分析的非线性方法尽管测量的是HRV的不同方面，但仍可用于评估自主神经平衡。
