Pulse wave velocity is associated with muscle mass decline: Health ABC study

Age-related mechanisms that lead to sarcopenia are not entirely understood. Basal leg blood flow declines with aging by augmented sympathetic vasoconstriction and arterial stiffening, thus a dysfunction in blood vessel dynamics may have an independent role on sarcopenia. We determined whether pulse wave velocity (PWV), marker of arterial stiffness, was associated with skeletal muscle decline. Observational cohort study of older adults(70-79 years) living in Pittsburgh, PA, USA or Memphis, TN, USA. Analyses included 2,405 participants. Correlations among muscle parameters including skeletal muscle density and intermuscular adipose tissue using mid-thigh CT scans were assessed. Linear mixed models tested the association between the change in the sarcopenic index (SI) (assessed by dual energy X-ray absorptiometry) over time and baseline PWV independently of multiple confounders. SI was defined: appendicular lean mass/squared height and calculated at every follow-up (n=6). Baseline PWV was significantly higher in black women compared to white women (930±431 vs. 843±366; p=0.0001), while there were no significant differences between black and white men (943±402 vs. 911±375; p=0.1786). Baseline analyses showed an independent negative association between PWV and muscle parameters after adjusting for confounders in both genders. The PWV-by-race interaction was significant in women and analyses are reported separately by race. Prospective mixed models showed that PWV was an independent determinant of the SI in all men (β=-0.1043; p=0.0065) and in white women (β=-0.1091; p=0.0192). In analyses examining the effect of arterial stiffness on limb lean mass over time, PWV correlated with lower leg (β=-0.2196; p=0.0002)and arm mass (β=-0.0985; p=0.0011) in all men and lower leg mass(β=-0.1608; p=0.0027)in white women. In older persons, arterial stiffening is associated with skeletal muscle mass decline differently for race and gender.