Association between arterial stiffness and walking capacity in older adults

Background and aim Arterial stiffening – a process that is largely due to intimal thickening, collagen disposition or elastin fragmentation – significantly contributes to cardiovascular events and mortality. There is also some evidence that it may negatively affect physical function. This study aimed to evaluate whether arterial stiffness was associated with measures of walking capacity in a large, population-based sample of highly aged older adults. Methods A population-based sample of 910 community-dwelling adults (aged 75, 80, or 85 years) were investigated in a cross-sectional observational study. Pulse wave velocity (PWV), a surrogate marker of arterial stiffness, was estimated based on the oscillometric recording of pulse waves at the brachial artery site. Walking capacity was assessed by 10-meter habitual walking speed, 10-meter maximum walking speed, and six-minute walk distance. We used multiple linear regression models to examine possible associations between PWV and parameters of walking capacity, and we adjusted the models for sex, age, socioeconomic status, anthropometry, physician-diagnosed diseases, prescription medication, smoking history, physical activity, and mean arterial pressure. Continuous variables were modelled using restricted cubic splines to account for potential nonlinear associations. Results Mean (standard deviation) 10-meter habitual walking speed, 10-meter maximum walking speed, and six-minute walk distance were 1.3 (0.2) m/s, 1.7 (0.4) m/s, and 413 (85) m, respectively. The fully adjusted regression models revealed no evidence for associations between PWV and parameters of walking capacity (all p-values >0.05). Conclusion Our results did not confirm previous findings suggesting a potential negative association between arterial stiffness and walking capacity in old age. Longitudinal studies, potentially taking additional confounders into account, are needed to disentangle the complex relationship between the two factors.peerReviewe

Association of Sit-to-Stand Capacity and Free-Living Performance Using Thigh-Worn Accelerometers among 60- to 90-Yr-Old Adults

Purpose Five times sit-to-stand (STS) test is commonly used as a clinical assessment of lower-extremity functional ability, but its association with free-living performance has not been studied. Therefore, we investigated the association between laboratory-based STS capacity and free-living STS performance using accelerometry. The results were stratified according to age and functional ability groups. Methods This cross-sectional study included 497 participants (63% women) 60-90 yr old from three independent studies. A thigh-worn triaxial accelerometer was used to estimate angular velocity in maximal laboratory-based STS capacity and in free-living STS transitions over 3-7 d of continuous monitoring. Functional ability was assessed with short physical performance battery. Results Laboratory-based STS capacity was moderately associated with the free-living mean and maximal STS performance (r = 0.52-0.65, P &lt; 0.01). Angular velocity was lower in older compared with younger and in low- versus high-functioning groups, in both capacity and free-living STS variables (all P &lt; 0.05). Overall, angular velocity was higher in capacity compared with free-living STS performance. The STS reserve (test capacity - free-living maximal performance) was larger in younger and in high-functioning groups compared with older and low-functioning groups (all P &lt; 0.05). Conclusions Laboratory-based STS capacity and free-living performance were found to be associated. However, capacity and performance are not interchangeable but rather provide complementary information. Older and low-functioning individuals seemed to perform free-living STS movements at a higher percentage of their maximal capacity compared with younger and high-functioning individuals. Therefore, we postulate that low capacity may limit free-living performance.</p

Ovatko nuoret aikuiset fyysisesti aktiivisempia kuin iäkkäät?

nonPeerReviewe

Comment on “Fatigability: A Prognostic Indicator of Phenotypic Aging”

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Comparing the associations between muscle strength, walking speed, and mortality in community-dwelling older adults of two birth cohorts born 28 years apart

Reduced age-specific mortality and increased muscle strength and walking speed of current older adults may have altered the relationships between these factors as more people may be above the reserve capacity threshold. We compared the cross-sectional associations between muscle strength and walking speed, and the associations of muscle strength and walking speed with five-year mortality between two population-based cohorts of 75- and 80-year-old people born 28 years apart. Maximal isometric grip and knee extension strength and walking speed were measured in 2017–2018 (n = 726). Mortality was ascertained from registers. The associations were compared with data of same-aged people studied in 1989–1990 with identical protocols (n = 500). The knee extension strength-walking speed relationship showed plateauing at higher strength levels among the later-born men, whereas the earlier-born men and women of both cohorts with lower strength levels were on the linear part of the curve. In the later-born women with lower five-year mortality rate (1.16 vs. 5.88 per 100 person-years), the association between grip strength and mortality was markedly different from the earlier cohort (HR 1.13 [95% CI 0.47–2.70] vs. 0.57 [0.37–0.86]). For knee extension strength and walking speed, the mortality hazards were similar between the cohorts, although statistically non-significant in the later-born women. In men, the later-born cohort showed similar associations as observed in the earlier-born cohort despite having lower mortality rate (2.93 vs. 6.44). Current older adults have more functional reserve that will likely help them to maintain walking ability for longer while also contributing to better survival.peerReviewe

Assessing physical performance and physical activity in large population-based aging studies : home-based assessments or visits to the research center?

Background The current study aims to compare correlations between a range of measures of physical performance and physical activity assessing the same underlying construct in different settings, that is, in a home versus a highly standardized setting of the research center or accelerometer recording. We also evaluated the selective attrition of participants related to these different settings and how selective attrition affects the associations between variables and indicators of health, functioning and overall activity. Methods Cross-sectional analyses comprising population-based samples of people aged 75, 80, and 85 years living independently in Jyväskylä, Finland. The AGNES study protocol involved the following phases: 1) phone interview (n = 1886), 2) face-to-face at-home interview (n = 1018), 3) assessments in the research center (n = 910), and 4) accelerometry (n = 496). Phase 2 and 3 included walking and handgrip strength tests, and phase 4 a chest-worn and thigh-worn accelerometer estimating physical activity and assessing posture, respectively, for 3–10 days in free-living conditions. Results Older people with poorer health and functioning more likely refrained from subsequent study phases, each requiring more effort or commitment from participants. Paired measures of walking speed (R = 0.69), handgrip strength (R = 0.85), time in physical activity of at least moderate intensity (R = 0.42), and time in upright posture (R = 0.30) assessed in different settings correlated with each other, and they correlated with indicators of health, functioning and overall activity. Associations were robust regardless of limitations in health and functioning, and low overall activity. Conclusions Correlational analyses did not clearly reveal one superior setting for assessing physical performance or physical activity. Inclusion of older people with early declines in health, functioning and overall activity in studies on physical performance and physical activity is feasible in terms of study outcomes, but challenging for recruitment.peerReviewe

Gait Variability Using Waist- and Ankle-Worn Inertial Measurement Units in Healthy Older Adults

Gait variability observed in step duration is predictive of impending adverse health outcomes among apparently healthy older adults and could potentially be evaluated using wearable sensors (inertial measurement units, IMU). The purpose of the present study was to establish the reliability and concurrent validity of gait variability and complexity evaluated with a waist and an ankle-worn IMU. Seventeen women (age 74.8 (SD 44) years) and 10 men (73.7 (4.1) years) attended two laboratory measurement sessions a week apart. Their stride duration variability was concurrently evaluated based on a continuous 3 min walk using a force plate and a waist- and an ankle-worn IMU. Their gait complexity (multiscale sample entropy) was evaluated from the waist-worn IMU. The force plate indicated excellent stride duration variability reliability (intra-class correlation coefficient, ICC = 0.90), whereas fair to good reliability (ICC = 0.47 to 0.66) was observed from the IMUs. The IMUs exhibited poor to excellent concurrent validity in stride duration variability compared to the force plate (ICC = 0.22 to 0.93). A good to excellent reliability was observed for gait complexity in most coarseness scales (ICC = 0.60 to 0.82). A reasonable congruence with the force plate-measured stride duration variability was observed on many coarseness scales (correlation coefficient = 0.38 to 0.83). In conclusion, waist-worn IMU entropy estimates may provide a feasible indicator of gait variability among community-dwelling ambulatory older adults.peerReviewe