BackgroundThe blood pressure (BP) is regulated by multiple neurophysiologic elements over multiple temporal scales. The multiscale dynamics of continuous beat-to-beat BP series, which can be characterized by “BP complexity”, may, thus, capture the subtle changes of those elements, and be associated with the level of functional status in older adults. We aimed to characterize the relationships between BP complexity and several important functions in older adults and to understand the underlying factors contributing to BP complexity.MethodA total of 400 older adults completed a series of clinical and functional assessments, a finger BP assessment of at least 10 min, and blood sample and vessel function tests. Their hypertensive characteristics, cognitive function, mobility, functional independence, blood composition, arterial stiffness, and endothelial function were assessed. The complexity of systolic (SBP) and diastolic (DBP) BP series was measured using multiscale entropy.ResultsWe observed that lower SBP and DBP complexity was significantly associated with poorer functional independence (β > 0.17, p < 0.005), cognitive function (β > 0.45, p = 0.01), and diminished mobility (β < −0.57, p < 0.003). Greater arterial stiffness (β < −0.48, p = 0.02), decreased endothelial function (β > 0.42, p < 0.03), and excessed level of blood lipids (p < 0.03) were the main contributors to BP complexity.ConclusionBlood pressure complexity is closely associated with the level of multiple functional statuses and cardiovascular health in older adults with and without hypertension, providing novel insights into the physiology underlying BP regulation. The findings suggest that this BP complexity metric would serve as a novel marker to help characterize and manage the functionalities in older adults.

The unique complexities of the outer‐skin curtain wall (CW) system of the Shanghai Tower increase the difficulty in evaluating its seismic performance. To assess such seismic performance, it is important to understand the floor acceleration demand under expected earthquake actions. Acceleration demand of the CW system consists of floor acceleration amplification (FAA) and floor response spectrum (FRS), which are closely related to the equivalent static seismic design force and the dynamic properties of the CW system. For estimating the FAA and FRS, code spectra compatible ground motions are selected and input to a finite element model of the building structure. The floor responses of key stories are analyzed. Normalized distribution of the horizontal FAA demand is estimated and shows that the obtained values exceed those proposed by current code provisions for low‐intensity earthquake excitations. It is noted that the vertical FAA demand has a different distribution profile than the horizontal one. The results indicate that FAA demand under three‐dimensional earthquake excitation is larger than that for 1D excitation. Moreover, the prime period range is up to 4.0 s for the horizontal FRS and up to 1.0 s for the vertical FRS. Horizontal and vertical FRS is proposed for dynamic analysis of the outer‐skin CW system of the Shanghai Tower.

Background Beat-to-beat blood pressure (BP) is an important cardiovascular output and regulated by neurophysiologic elements over multiple temporal scales. The multiscale dynamics of beat-to-beat BP fluctuation can be characterized by “BP complexity” and has been linked to age-related adverse health outcomes. We here aimed to examine whether BP complexity mediates the association between arterial stiffness and frailty. Method This cross-sectional study was completed between January and October 2021. A total of 350 older adults completed assessments for frailty, arterial stiffness ((i.e., average brachial-ankle pulse wave velocity), and beat-to-beat finger BP. The complexity of beat-to-beat systolic (SBP) and diastolic (DBP) BP series were measured using multiscale entropy. The relationships between frailty, BP complexity and arterial stiffness were examined using ANOVA and linear regression models. The effects of BP complexity on the association between arterial stiffness and frailty were examined using mediation analyses. Results Compared to non-frail, pre-frail and frail groups had significantly elevated lower SBP and DBP complexity (F>11, p<0.001), and greater arterial stiffness (F=16, p<0.001). Greater arterial stiffness was associated with lower BP complexity (β<-0.42, p<0.001). SBP and DBP complexity mediated the association between arterial stiffness and frailty (indirect effects>0.28), account for at least 47% of its total effects on frailty (Mediated proportion: SBP: 50%, DBP: 47%). Conclusion This study demonstrates the association between BP complexity and frailty in older adults, and BP complexity mediates the association between arterial stiffness and frailty, suggesting that this metric would serve as a marker to help characterize important functions in older adults.