Tulppo M P, Mäkikallio T H, Seppänen T, Laukkanen R T, Huikuri H V
Department of Medicine, University of Oulu, Finland.
Am J Physiol. 1998 Feb;274(2):H424-9. doi: 10.1152/ajpheart.1998.274.2.H424.
This study was designed to assess the effects of age and physical fitness on vagal modulation of heart rate (HR) during exercise by analyzing the instantaneous R-R interval variability from Poincaré plots (SD1) at rest and at different phases of a bicycle exercise test in a population of healthy males. SD1 normalized for the average R-R interval (SD1n), a measure of vagal activity, was compared at rest and during exercise among subjects of ages 24-34 (young, n = 25), 35-46 (middle-aged, n = 30), and 47-64 yr (old, n = 25) matched for peak O2 consumption (VO2 peak) and among subjects with VO2 peak of 28-37 (poor, n = 25), 38-45 (average, n = 36), and 46-60 ml.kg-1.min-1 (good, n = 25) matched for age. SD1n was higher at rest in the young subjects than in the middle-aged or old subjects (39 +/- 14, 27 +/- 16, and 21 +/- 8, respectively; P < 0.001), but the age-related differences in SD1n were smaller during exercise [e.g., 11 +/- 5, 9 +/- 5, and 8 +/- 4 at the level of 100 W; P = not significant (NS)]. The age-matched subjects with good, average, and poor VO2 peak showed no difference in SD1n at rest (32 +/- 17, 28 +/- 13, and 26 +/- 11, respectively; P = NS), but SD1n differed significantly among the groups from a low to a moderate exercise intensity level (e.g., 13 +/- 6, 10 +/- 5, and 6 +/- 3 for good, average, and poor fitness groups, respectively; P < 0.001, 100 W). These data show that poor physical fitness is associated with an impairment of cardiac vagal function during exercise, whereas aging itself results in more evident impairment of vagal function at rest.
本研究旨在通过分析健康男性群体在静息状态以及自行车运动试验不同阶段的庞加莱图（SD1）中的瞬时R-R间期变异性，评估年龄和身体素质对运动中心率（HR）迷走神经调节的影响。将反映迷走神经活动的指标——经平均R-R间期标准化后的SD1（SD1n），在静息状态和运动期间，于峰值摄氧量（VO2峰值）匹配的24 - 34岁（年轻组，n = 25）、35 - 46岁（中年组，n = 30）和47 - 64岁（老年组，n = 25）的受试者之间进行比较；同时也在年龄匹配的VO2峰值为28 - 37（差，n = 25）、38 - 45（中等，n = 36）和46 - 60 ml·kg-1·min-1（好，n = 25）的受试者之间进行比较。年轻受试者静息时的SD1n高于中年或老年受试者（分别为39±14、27±16和21±8；P < 0.001），但运动期间SD1n的年龄相关差异较小[例如，在100 W水平时分别为11±5、9±5和8±4；P = 无显著性差异（NS）]。VO2峰值良好、中等和较差的年龄匹配受试者在静息时的SD1n无差异（分别为32±17、28±13和26±11；P = NS），但在低至中等运动强度水平下，各组之间的SD1n存在显著差异（例如，良好、中等和较差身体素质组在100 W时分别为13±6、10±5和6±3；P < 0.001）。这些数据表明，身体素质差与运动期间心脏迷走神经功能受损有关，而衰老本身导致静息时迷走神经功能受损更为明显。
