Cardiovagal and somatic sensory nerve functions in healthy subjects

Heart rate response to deep breathing (HRDB), which depends on the integrity of cardiac vagal preganglionic neurons and efferent fibers, and the function of sural nerve fibers are both associated with an age-related decline process. The aim of this study was to determine whether the effects attributed to aging on cardiovagal and sural nerve function decline are associated.

HRDB and sural sensory nerve action potential (SNAP) amplitude, latency, and conduction velocity (SCV) were measured in one hundred healthy asymptomatic subjects (aged 14-92 years, 41 women). Multiple and simple linear regressions were used to analyze the relationships between the variables.

There were significant linear relationships between sural SNAP amplitude and HRDB with age. There was also a significant linear relationship between sural SNAP amplitude and HRDB (correlation coefficient 0.46, p<0.0001), but the model explained only 21.5 % of the variability in HRDB.

Cardiovagal function assessed by HRDB is associated with sural SNAP amplitude in healthy subjects. Age-related decline only partially explained the variability seen in the association. Other genetic and environmental factors may also play a role.