Age-associated loss of muscular strength and muscular power is a critical determinant of loss of physical function and progression to disability in older adults. In this study, we examined the association of systemic vascular function and measures of muscle strength and power in older adults. Measures of vascular endothelial function included brachial artery flow-mediated dilation (FMD) and the pulse wave amplitude reactive hyperemia index (PWA-RHI). Augmentation index (AIx) was taken as a measure of systemic vascular function related to arterial stiffness and wave reflection. Measures of muscular strength included one repetition maximum (1RM) for a bilateral leg press. Peak muscular power was measured during 5 repetitions performed as fast as possible for bilateral leg press at 40% 1RM. Muscular power was associated with brachial FMD ( ？？ = 0 . 4 3 , ？？ < 0 . 0 5 ), PWA-RHI ( ？？ = 0 . 4 2 , ？？ < 0 . 0 5 ), and AIx ( ？？ = ？ 0 . 5 4 , ？？ < 0 . 0 5 ). Muscular strength was not associated with any measure of vascular function. In conclusion, systemic vascular function is associated with lower-limb muscular power but not muscular strength in older adults. Whether loss of muscular power with aging contributes to systemic vascular deconditioning or vascular dysfunction contributes to decrements in muscular power remains to be determined. 1. Introduction As life expectancy in the United States continues to rise, the maintenance of physical independence of older adults has also emerged as a major clinical and public health priority. A critical factor in an older person’s ability to function independently is the ability to move without assistance. Older adults who lose mobility are less likely to remain in the community, have higher rates of mortality, and experience a poorer quality of life [1, 2]. Age-associated loss of muscular strength (the ability to generate maximal muscle force) and muscular power (the product of the force and velocity of muscle contraction) is an important determinant of this loss of physical function and progression to disability . Interestingly, although muscular strength and power are associated, muscular power has been shown to be a stronger predictor of physical function than muscular strength in older adults [4, 5]. Poor muscular power is associated with a 3-fold greater risk for mobility impairment than poor muscle strength  and improving muscular power leads to improvements in physical function independent of changes in muscular strength . Although numerous potential mechanisms have been put forth, no single common
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