Assessment of Autonomic Functions in the Normotensive Offspring of Hypertensive Parents

Hypertension is inheritable and various genetic mechanisms have been imputed to its causation. Though the genetic mechanisms behind inherited hypertension could be many the early manifestation of the cardiovascular dysregulation is reflected by the altered sympathovagal balance. As sympathovagal balance maintains the normal regulation of cardiovascular system, any disruption in its homeostasis can gradually lead to cardiovascular diseases especially hypertension. Therefore this study has been designed to assess the autonomic functions by the orthostatic test in the normotensive offspring of hypertensive parents.

This cross-sectional observational study was carried out on 50 healthy normotensive volunteers with parental history of hypertension and 50 healthy normotensive volunteers without parental history of hypertension. The change in BP (sympathetic function) and heart rate-30: 15 ratio (parasympathetic test) in response to change in posture was assessed (othostatic test).

The assessment of the sympathetic and parasympathetic components of orthostatic test revealed a statistically significant increase in the sympathetic response and parasympathetic attenuation to change in posture as inferred by the significant difference in responses between the groups.

From the observations of our study it could be inferred that the normotensive offspring of hypertensive parents, though normotensives at rest, had a higher sympathetic response to physical stimuli suggesting sympathetic overactivity, thus making the inference of impaired sympathovagal balance in them.