Autonomic reactivity in normal healthy children of hypertensives

<p><strong>Objectives: </strong>A study was undertaken to compare the reactivity between the offspring of normotensive parents and hypertensive parents. Autonomic functions were compared during rest and during physical stress. <strong>Study</strong> <strong>Design:</strong> Study was done with 80 subjects divided into two groups of 40 each. Subjects were grouped by the presence of parental hypertension &ge;5 years. Blood pressure of &ge;140/90 mm of Hg was used for classiffication (WHO Classification). Blood pressure of &le;120/80 mm of Hg was used for normotensives. Subjects were all normotensive and were in the age group of 18-27 years. Autonomic functions and heart rate variability were recorded for the study and compared between both the groups. <strong>Results: </strong>The basal systolic (P&lt;0.05) and diastolic pressures (P&lt;0.05) and pulse rate (P&lt;0.05) were found to be elevated in the study group. Autonomic functions such as heart rate and blood pressure changes during standing (P&lt;0.05), cold pressor test (P&lt;0.0001) and Valsalva maneuver (P&lt;0.05) significantly differed between the groups. Heart rate variability showed elevated LF/HF Ratio (P&lt;0.0001) and SDNN and RMSSD were decreased in the study groups (P&lt;0.05). <strong>Conclusion:</strong> Heart Rate Variability and autonomic functions testing showed significantly increased sympathetic tone and the decreased parasympathetic activity before the onset of hypertension in predisposed individuals. This was evidenced by abnormality in basal levels of autonomic functions in rest and during reactivity to the physical stress in the subjects</p>