Autonomic Function Assessment in Normotensive Offspring of Hypertensive Parents

Background: Hypertension is a multifactorial disorder with strong familial predisposition. Autonomic nervous system imbalance has been implicated as an early mechanism in the pathogenesis of essential hypertension. Normotensive offspring of hypertensive parents may exhibit subclinical autonomic alterations before the development of sustained elevation in blood pressure.

Aim: To assess autonomic function in normotensive offspring of hypertensive parents and compare the findings with offspring of normotensive parents.

Materials and Methods: This cross-sectional comparative study included 100 healthy individuals aged 18–25 years, divided into two groups: 50 normotensive offspring of hypertensive parents (study group) and 50 normotensive offspring of normotensive parents (control group). Autonomic function was evaluated using heart rate variability (HRV) analysis and standardized cardiovascular reflex tests, including deep breathing test (E:I ratio), Valsalva maneuver, 30:15 ratio, isometric handgrip test, and cold pressor test. Statistical analysis was performed using appropriate parametric and non-parametric tests, with p < 0.05 considered significant.

Results: The study group demonstrated significantly higher resting heart rate, reduced HRV indices (SDNN, RMSSD, HF power), and elevated LF/HF ratio compared to controls (p < 0.05). Parasympathetic function tests showed reduced E:I ratio, Valsalva ratio, and 30:15 ratio in the study group. Sympathetic reactivity was significantly increased, as evidenced by exaggerated blood pressure responses to isometric handgrip and cold pressor tests.

Conclusion: Normotensive offspring of hypertensive parents exhibit early autonomic dysfunction characterized by sympathetic predominance and reduced parasympathetic activity. These alterations may represent early markers of future hypertension and highlight the importance of preventive strategies in high-risk individuals.