Abstract 19626: Muscle Weakness Induces Left Ventricular Hypertrophy via Frequent Elevation of Functional Arterial Stiffness During Exercise in Patients With Hypertension

Abstract

Background: Hypertension (HT) characterized by autonomic imbalance, is well known to induce an inappropriate elevation of arterial stiffness resulting in left ventricular hypertrophy (LVH). On the other hand, decreased muscle strength enhances autonomic imbalance by stimulating muscle sympathetic activity during exercise even at low- or moderate-intensity. However, it is unclear whether muscle weakness induces LVH via frequent elevation of functional arterial stiffness during exercise in patients with HT. The aim of this study was to investigate the relationships among muscle strength, autonomic activity during exercise, functional arterial stiffness and LVH in them. Methods: Fifty-five patients with HT aged 68±9 years, 32 males and 23 females, participated in this study. We measured plasma brain natriuretic peptide (BNP) and LV mass index (LVMI) on echocardiogram as parameters of LV overload and LVH, respectively, and knee extension muscle strength. Patients performed a treadmill exercise test to examine heart rate recovery (HRR). We assessed the changes from baseline values of plasma noradrenalin (NA) and brachial-ankle pulse wave velocity (PWV) to those measured just after a cycle ergometer exercise test that was performed at moderate-intensity ([[Unable to Display Character: ⊿]]NA and [[Unable to Display Character: ⊿]]PWV, respectively). The HRR, [[Unable to Display Character: ⊿]]NA and [[Unable to Display Character: ⊿]]PWV were used as parameters of parasympathetic and sympathetic activities and functional arterial stiffness, respectively. We analyzed the relationships among muscle strength, HRR, [[Unable to Display Character: ⊿]]NA, [[Unable to Display Character: ⊿]]PWV, BNP and LVMI. Results: Muscle strength was negatively correlated with [[Unable to Display Character: ⊿]]NA (r=-0.23, P<0.05), [[Unable to Display Character: ⊿]]PWV (r=-0.24, P<0.05), BNP (r=-0.23, P<0.05) and LVMI (r=-0.23, P<0.05). No significant relationship was observed between muscle strength and HRR. LVMI was positively correlated with [[Unable to Display Character: ⊿]]PWV (r=0.28, P<0.05). Conclusion: Muscle weakness induced LVH via frequent elevation of functional arterial stiffness caused by autonomic imbalance during exercise in patients with HT.