Association of Sympathovagal Imbalance with Cognitive Deficit, Insulin Resistance and Oxidative Stress in Newly Diagnosed Hypertension

Subathra Thiruchengodu Ammaiyappan; Gopal Krushna Pal; Dhanalakshmi Yerrabelli; Pravati Pal; Nivedita Nanda

doi:10.5530/ijcep.2018.5.3.9

Subathra Thiruchengodu Ammaiyappan Department of Physiology, Jawaharlal Institute of Post-graduate Medical education and Research (JIPMER), Puducherry – 605 006, INDIA.
Gopal Krushna Pal Department of Physiology, Jawaharlal Institute of Post-graduate Medical education and Research (JIPMER), Puducherry – 605 006, INDIA.
Dhanalakshmi Yerrabelli Department of Physiology, Jawaharlal Institute of Post-graduate Medical education and Research (JIPMER), Puducherry – 605 006, INDIA.
Pravati Pal Department of Physiology, Jawaharlal Institute of Post-graduate Medical education and Research (JIPMER), Puducherry – 605 006, INDIA.
Nivedita Nanda Department of Biochemistry, Jawaharlal Institute of Post-graduate Medical education and Research (JIPMER), Puducherry – 605 006, INDIA.

DOI: https://doi.org/10.5530/ijcep.2018.5.3.9

Keywords: Newly diagnosed hypertension, Sympathovagal imbalance, Cognitive deficit, Insulin resistance, Oxidative stress

Abstract

Background and Aim: Hypertension has been reported to be caused by sympathovagal imbalance and is associated with a wide variety of cognitive loss. The aim of present study is to study the association of sympathovagal imbalance with cognitive deficit, insulin resistance and oxidative stress in newly diagnosed hypertensive subjects. Methods: 84 subjects (42 normotensives and 42 hypertensives) aged between 18-44 years were included in this case-control study. The demographic, anthropometric, basal parameters, heart rate variability (HRV), cardiovascular autonomic function tests (CAFTs), event-related potential P300 and biochemical parameters were recorded. Association of various factors with cognitive deficit was studied by Pearson correlation analysis and independent contribution of factors to cognitive deficit was assessed by multiple regression analysis. Results: LF-HF ratio was increased and total power of HRV was reduced in hypertensives. Among CAFTs, 30:15 ratio and DDBPIHG group were increased; E: I ratio was decreased in hypertensive group. The latency of P300 was significantly prolonged in hypertensives and P300 latency was positively correlated and linked with LF: HF ratio (the marker of SVI) in hypertensives. The fasting blood glucose, insulin, HOMA-IR, hsCRP and total oxidant capacity were increased and antioxidant status was decreased in hypertensive groups. Conclusion: Newly diagnosed hypertensive subjects have sympathovagal imbalance and considerable memory impairment even before medical intervention. Insulin resistance and oxidative stress contribute to the memory impairment and sympathovagal imbalance could be the physiological link for cognitive loss in newly diagnosed hypertensive subjects.