The relation between low frequency and high frequency components of heart rate variability represents the balance between the two branches of the autonomic nervous system. The high frequency component reflecting sinus arrhythmia, has been attributed to the modulation of the parasympathetic output. The low frequency component has been referred to both sympathetic and parasympathetic activity.
The experimental design was identical to the previous study detailed in the reference article.
|Exposure duration||continuous for 8 h|
|Pulse width||577 µs|
|Repetition frequency||217 Hz|
|Distance between exposed object and exposure source||40 cm|
|Setup||The mobile phone was positioned at a distance of 40 cm to the vertex with the antenna axis perpendicular to the axis of the subject's body.|
|Additional info||After an adaptation night, polysomnographies were performed during two successive nights. Each subject was exposed to the EMF in one night and not exposed in the other night (randomized and blinded).|
Under these experimental conditions, the autonomic control of heart rate was not affected by weak high frequency electromagnetic fields emitted by digital mobile phones.
For most parameters, significant differences between different sleep stages were revealed. In particular, slow wave sleep was characterized by a low ratio of low frequency and high frequency components, indicating a predominance of the parasympathetic over the sympathetic tone. In contrast, during REM sleep the autonomic balance was shifted in favor of the sympathetic activity. For all heart rate parameters, no significant effects were detected under exposure compared to sham exposure.