The amount of muscular sympathetic activity, measured as number of bursts per 100 heart beats, varies considerably between subjects but, on the other hand, it is highly reproducible over time within the individual subject. However, there is some increase with age. Counter-intuitively, there seems to be only a weak and barely significant correlation between sympathetic efferent activity and hypertension as found in group studies.
The amount of muscular sympathetic activity, measured as bursts per 100 heartbeats, varies greatly among individuals but remains consistent over time within each person. Age is associated with an increase in this activity. Surprisingly, there's a weak and insignificant link between sympathetic nerve activity and hypertension observed in group studies.