Aerobic Exercise Training Decreases Plasma Asymmetric Dimethylarginine Concentrations With Increase in Arterial Compliance in Postmenopausal Women Koichiro Tanahashi,1 Nobuhiko Akazawa,1 Asako Miyaki,1 Youngju Choi,2 Song-Gyu Ra,1 Tomoko Matsubara,1 Hiroshi Kumagai,1 Satoshi Oikawa,1 and Seiji Maeda2

Arterial compliance plays an important role in the vascular function (i.e., arterial buffering function of the pulsation of blood pressure and flow). Reduction in central arterial compliance is an independent risk factor for cardiovascular disease.1 Central arterial compliance decreases with advancing age.2,3 In addition, postmenopausal women have lower central arterial compliance than premenopausal women.4 We and other researchers have shown that regular aerobic exercise increases central arterial compliance in healthy, postmenopausal women.5,6 However, the precise mechanisms underlying the aerobic exercise training–induced increase in central arterial compliance are unclear. Endothelium-derived nitric oxide (NO) is the most potent endogenous vasodilator.7 Endogenous NO contributes to the regulation of vascular tone, arterial compliance, and arterial stiffness.8,9 NO is synthesized from l-arginine by nitric oxide synthase (NOS) in the endothelium.10 Asymmetric dimethylarginine (ADMA) is an endogenous competitive inhibitor of NOS. An increase in ADMA is associated with impairment of NO synthesis.11 Furthermore, plasma concentrations of ADMA increase in elderly people and in postmenopausal women.12,13 However, the effect of aerobic exercise training on ADMA in healthy, postmenopausal women has not been investigated. The purpose of this study was to examine the effects of aerobic exercise training on central arterial compliance and plasma ADMA concentrations. We hypothesized that the decrease in plasma ADMA concentrations induced by aerobic exercise training would contribute to increase in arterial compliance. In this study, we measured plasma ADMA concentrations and carotid arterial compliance before and after a 12-week aerobic exercise training intervention in postmenopausal women. Aerobic Exercise Training Decreases Plasma Asymmetric Dimethylarginine Concentrations With Increase in Arterial Compliance in Postmenopausal Women