Age moderates the association between handgrip strength and large artery stiffness in women.

Women's cardiovascular disease risk increases during midlife, in part, due to accelerated vascular dysfunction. Age-related vascular dysfunction includes increases in large artery stiffness, which may be mitigated by maintaining muscular strength. However, the relationship between handgrip strength and large artery stiffness through the lifespan in women is unknown. The present purpose was to evaluate the relationship between handgrip strength and large artery stiffness in women. Maximal voluntary contraction relative to body weight (MVC/BW), carotid artery stiffness (β-stiffness), and aortic stiffness [carotid-femoral pulse wave velocity (cfPWV)] were measured in 216 women (<i>n</i> = 54 young 29 ± 9 yr, <i>n</i> = 73 middle-aged 56 ± 6 yr, and <i>n</i> = 89 older 72 ± 6 yr). Multivariate linear regression was used to evaluate the relationship between large artery stiffness and MVC/BW, age, and the MVC/BW by age interaction while adjusting for potential confounders. In the fully adjusted model, age [<i>B</i> = 0.23 (95% CI, 0.12, 0.35), <i>P</i> < 0.001] and the age by MVC/BW interaction [<i>B</i> = -0.28 (-0.55, -0.02), <i>P</i> = 0.04] were associated with β-stiffness. Similar results were observed with cfPWV [age: <i>B</i> = 0.15 (0.09, 0.20), <i>P</i> < 0.001; age × MVC/BW: <i>B</i> = -0.15 (0.28, -0.02) <i>P</i> = 0.02], which remained after further adjustment for mean arterial pressure. Simple slope analyses revealed inverse associations between MVC/BW and cfPWV (<i>P</i> = 0.02) and β-stiffness (<i>P</i> = 0.07) among older women, with weak to no associations observed among young or middle-aged women (<i>P</i> = 0.19-0.75). Age modifies the relationship between relative handgrip strength and large artery stiffness in women. The direction of the relationship between relative handgrip strength and large artery stiffness changes across the lifespan in women, with greater handgrip strength being associated with lower large artery stiffness after middle age.<b>NEW & NOTEWORTHY</b> The present study investigated the association between relative handgrip strength and large artery stiffness in women across the lifespan. Greater relative handgrip strength was not associated with large artery stiffness in young or middle-aged women but was associated with lower large artery stiffness in older women. This age-moderating effect suggests the impact of muscular strength on large artery stiffness changes across the lifespan and becomes more important for vascular health in women following midlife.