Background

Exercise stress testing is frequently used to expose cardiac arrhythmias. Aerobic exercise conditioning has been used as a nonpharmacologic antiarrhythmic intervention.

Objective

The purpose of this study was to test the hypothesis that noninvasively recorded skin sympathetic nerve activity (SKNA) is increased during exercise and that SKNA response varies according to fitness levels.

Methods

Oxygen consumption (VO₂) and SKNA were recorded in 39 patients undergoing an incremental exercise test. Patients were grouped by 5 levels of fitness based on age, sex, and VO₂max.

Results

With exercise, all patients had a significant increase in average SKNA (aSKNA) (1.58 ± 1.12 μV to 4.50 ± 3.06 μV, P = .000) and heart rate (HR) (87.40 ± 20.42 bpm to 154.13 ± 16.82 bpm, P = .000). A mixed linear model of aSKNA was used with fixed effects of fitness, exercise time, and recovery time, and random effects of subject level intercept and slopes for exercise time and recovery times. The poor fitness group had significantly higher aSKNA than the other groups (P = .0273). For all subjects studied, aSKNA increased by 5% per minute with progression of exercise and decreased by 15% per minute with progression of recovery. The fitness variable encodes information on both comorbidities and body mass index (BMI). Once fitness level is known, comorbidities and BMI are not significantly associated with aSKNA. In all groups, aSKNA positively correlated with HR (R² = 0.47 ± 0.23) and VO₂ (R² = 0.68 ± 0.25).

Conclusion

Fitness level determines the magnitude and time course of SKNA increase during exercise. SKNA may be a useful fitness biomarker in exercise stress testing.

中文翻译：

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皮肤交感神经活动作为健康的生物标志物

 背景

运动压力测试经常用于暴露心律失常。有氧运动调节已被用作非药物抗心律失常干预措施。

 客观的

本研究的目的是检验以下假设：运动期间无创记录的皮肤交感神经活动 (SKNA) 会增加，并且 SKNA 反应会根据健身水平而变化。

 方法

记录了 39 名接受增量运动测试的患者的耗氧量 (VO ₂ ) 和 SKNA。根据年龄、性别和₂最大摄氧量，将患者按 5 个健康水平进行分组。

 结果

通过运动，所有患者的平均 SKNA (aSKNA)（1.58 ± 1.12 μV 至 4.50 ± 3.06 μV， P = .000）和心率 (HR)（87.40 ± 20.42 bpm 至 154.13 ± 16.82 bpm， P = . .000）。使用 aSKNA 的混合线性模型，具有健身、运动时间和恢复时间的固定效应，以及运动时间和恢复时间的受试者水平截距和斜率的随机效应。健康状况不佳组的 aSKNA 显着高于其他组 ( P = .0273)。对于所有研究对象，随着运动的进展，aSKNA 每分钟增加 5%，随着恢复的进展，aSKNA 每分钟减少 15%。健康变量编码有关合并症和体重指数 (BMI) 的信息。一旦了解健康水平，合并症和 BMI 与 aSKNA 就不显着相关。在所有组中，aSKNA 与 HR (R ² = 0.47 ± 0.23) 和 VO ₂ (R ² = 0.68 ± 0.25) 呈正相关。

 结论

体能水平决定了运动过程中 SKNA 增加的幅度和时间过程。 SKNA 可能是运动压力测试中有用的健身生物标志物。