Goldsmith R L, Bigger J T, Bloomfield D M, Steinman R C
Division of Circulatory Physiology, Columbia University, College of Physicians and Surgeons, New York, NY, USA.
Med Sci Sports Exerc. 1997 Jun;29(6):812-7. doi: 10.1097/00005768-199706000-00012.
The association between increasing age and decreasing vagal modulation is well known. However, the importance of fitness as a determinant of the decline in vagal modulation with age is not established. To test the hypothesis that decreasing vagal modulation is largely a function of declining fitness rather than increasing age, we studied a sample of healthy volunteers with a wide range of fitness levels, but a narrow age range. We assessed fitness by measuring the maximal oxygen uptake (VO2max) achieved during incremental bicycle exercise. Vagal modulation was assessed by calculating high frequency power (0.15-0.40 Hz) of the RR variability power spectrum from 24-h ECG recordings. We studied 37 healthy volunteers who were 22-44 yr old. In our sample, VO2max ranged from 25 to 70 mL.min-1.kg-1 (mean of 45 +/- 13). Age was not significantly related to high frequency power, but VO2max was highly correlated with high frequency power (r = 0.74, P = 0.0001), indicating that physical fitness is strongly associated with vagal modulation. Thus, the decline in vagal modulation often attributed to increasing age may, instead, be the result of a decline in fitness.
年龄增长与迷走神经调节能力下降之间的关联已为人熟知。然而，体能作为年龄增长导致迷走神经调节能力下降的一个决定因素，其重要性尚未明确。为了验证迷走神经调节能力下降主要是由于体能下降而非年龄增长这一假设，我们研究了一组健康志愿者，他们体能水平差异较大，但年龄范围较窄。我们通过测量递增式自行车运动中达到的最大摄氧量（VO2max）来评估体能。通过计算24小时心电图记录的RR间期变异性功率谱的高频功率（0.15 - 0.40赫兹）来评估迷走神经调节能力。我们研究了37名年龄在22 - 44岁的健康志愿者。在我们的样本中，VO2max范围为25至70毫升·分钟-1·千克-1（平均值为45±13）。年龄与高频功率无显著相关性，但VO2max与高频功率高度相关（r = 0.74，P = 0.0001），表明体能与迷走神经调节密切相关。因此，通常归因于年龄增长的迷走神经调节能力下降，可能实际上是体能下降的结果。
