Evaluation of cardiac autonomic reactivity among young healthy male offspring of hypertensive parents in response to aerobic exercise: A cross-sectional study

Madhumita Mukherjee; Sujoy Mukherjee; Goutam Banerjee

Volume : VIII, Issue : XII, December - 2018

Evaluation of cardiac autonomic reactivity among young healthy male offspring of hypertensive parents in response to aerobic exercise: A cross-sectional study

Madhumita Mukherjee, Sujoy Mukherjee, Goutam Banerjee

Abstract :

BACKGROUND: The present literature suggests that the interaction of both genetic predisposition and the environment are integrally involved with the future development of hypertension in normotensive offspring of hypertensive parents (NOHP). The key marker for the future development of hypertension in them is heightened cardiovascular reactivity to mental stress and exercise test. Compare to maximal, supra–maximal and high intensity chronic exercise, assessment of cardiac autonomic response among male NOHP at rest and during recovery phase of single bout of sub–maximal aerobic exercise has been given little attention till date.

OBJECTIVE: The aim of this study was to evaluate the cardiac autonomic reactivity among young male NOHP in response to sub–maximal aerobic exercise.

METHODS: An observation and cross–sectional study was conducted on 50 young healthy male subjects aged 18–25 years who were divided in two groups: normotensive offspring of hypertensive (NOHP) and normotensive offspring of normotensive parents (NONP) in 1:1 ratio. Blood pressure (BP) was recorded at rest and immediately after termination of exercise. A short–term heart rate variability (HRV) test was conducted for five minutes in supine position at rest and last five minutes of 15 minutes recovery phase after a single bout of submaximal (50% VO_2max) aerobic exercise using treadmill machine and following modified Black–Bruce protocol as well as Astrand–Rhyming nomogram. BP, Heart rate (HR) [basal and recovery], rate pressure product (RPP) and HRV frequency domain Indices (FDI) such as normalized LF (LFnu), normalized HF (HFnu), LF–HF ratio and total power (TP) were analysed using Graph Pad Quickcalc software.

RESULTS: Significantly higher SBP and DBP were noted immediately after termination of exercise among NOHP compared to NONP. Increased LFnu and LF/HF ratio as well as decreased HFnu were observed in NOHP subjects in comparison to NONP population both at basal state and during recovery phase after exercise. In addition to that, a significant negative correlation between TP and RPP [r: −0.486; p: 0.013] was there among NOHP at rest.

CONCLUSION: Study indicated that autonomic dysfunction in NOHP manifested in the form of increased sympathetic activity and vagal inhibition and overall sympathovagal imbalance (SVI). Attenuated parasympathetic potency of cardiac modulation substantially linked to increase myocardial workload and oxygen demand in NOHP even at rest. Hence impaired cardiac autonomic modulations in healthy young male NOHP could lead to develop hypertension in future.