Muscle Weakness Is Associated With an Increase of Left Ventricular Mass Through Excessive Blood Pressure Elevation During Exercise in Patients With Hypertension

摘要

Autonomic imbalance in hypertension induces excessive blood pressure (BP) elevation during exercise, thereby increasing left ventricular mass (LVM). Although muscle weakness enhances autonomic imbalance by stimulating muscle sympathetic activity during exercise, it is unclear whether muscle weakness is associated with an increase of LVM in patients with hypertension. This study aimed to investigate the relationships between muscle weakness, BP elevation during exercise, and LVM in these patients. Eighty-six hypertensive patients aged 69 +/- 8 years with controlled resting BP (ie, < 140/90 mmHg) were recruited. Plasma brain natriuretic peptide (BNP), left ventricular mass index (LVMI), and knee extension muscle strength were measured. Changes in plasma noradrenaline (NORA) and brachial-ankle pulse wave velocity (ba-PWV) were assessed before and after an ergometer exercise test performed at moderate intensity (Delta NORA and Delta PWV, respectively). A difference between baseline and peak systolic BP during the exercise test was defined as BP elevation during exercise (ASBP). Relationships between muscle strength, Delta NORA, Delta PWV, Delta SBP, BNP, and LVMI were analyzed, and significant factors increasing LVM were identified using univariate and multivariate regression analyses. Muscle strength was negatively correlated with Delta NORA (r = -0.202, P = 0.048), Delta PWV (r = -0.328, P = 0.002), Delta SBP (r = -0.230, P = 0.033), BNP (r = -0.265, P = 0.014), and LVMI (r = -0.233, P = 0.031). LVMI was positively correlated with Delta PWV (r = 0.246, P = 0.023) and ASBP (r = 0.307, P = 0.004). Muscle strength was a significant independent factor associated with LVMI = -0.331, P = 0.010). Our findings suggest that muscle weakness is associated with an increase of LVM through excessive BP elevation during exercise in patients with hypertension.