Longitudinal changes in life-space mobility and autonomy in participation outdoors among Finnish community-dwelling older adults from pre-COVID-19 to through the pandemic.

BACKGROUND: Among older people, community mobility was reduced at the beginning of the COVID-19 pandemic, but the longer-term changes are unclear. AIMS: To study lower extremity performance and car driving as predictors of changes in older adults' life-space mobility, autonomy in participation outdoors, and the risk of developing restricted life-space mobility from 2017 to 2022. METHODS: Life-space mobility (scoring range 0-120) and autonomy in participation outdoors (scoring range 0-20) were assessed in community-dwelling individuals (n = 657) in 2017-2018 (baseline age 75, 80, or 85 years), during the first wave of COVID-19 in 2020, and in 2021-2022. Lower extremity performance was assessed using the Short Physical Performance Battery, and car driving was self-reported at baseline. Data were analysed using generalized estimating equations and Cox regression. RESULTS: During the first wave of COVID-19 in 2020, life-space mobility decreased on average by 10.3 (SD 21.6) points and partially recovered in 2021-2022 (+ 2.7, SD 21.8). The same pattern was observed for autonomy in participation outdoors. Non-drivers and those with impaired lower extremity performance had a 2.4-to-3.6-fold adjusted risk of developing restricted life-space mobility over the follow-up period compared to drivers with intact lower extremity performance. CONCLUSIONS: For older people, the recovery of community mobility was incomplete after the restrictions stemming from the pandemic were lifted. Older adults with impaired lower extremity performance and who did not drive were particularly vulnerable to developing restricted life-space mobility, a situation that could lead to social isolation and reduced well-being.

Genome-Wide Polygenic Score for Muscle Strength Predicts Risk for Common Diseases and Lifespan: A Prospective Cohort Study.

BACKGROUND: We used a polygenic score for hand grip strength (PGS HGS) to investigate whether genetic predisposition for higher muscle strength predicts age-related noncommunicable diseases, survival from acute adverse health events, and mortality. METHODS: This study consisted of 342 443 Finnish biobank participants from FinnGen Data Freeze 10 (53% women) aged 40-108 with combined genotype and health registry data. Associations between PGS HGS and a total of 27 clinical endpoints were explored with linear or Cox regression models. RESULTS: A higher PGS HGS was associated with a reduced risk of selected common noncommunicable diseases and mortality by 2%-10%. The risk for these medical conditions decreased by 5%-23% for participants in the highest PGS HGS quintile compared to those in the lowest PGS HGS quintile. A 1 standard deviation (SD) increase in the PGS HGS predicted a lower body mass index (ß = -0.112 kg/m2, standard error [SE] = 0.017, p = 1.69E-11) in women but not in men (ß = 0.004 kg/m2, p = .768). PGS HGS was not associated with better survival after acute adverse health events compared to the nondiseased period. CONCLUSIONS: The genotype that supports higher muscle strength appears to protect against future health adversities, albeit with modest effect sizes. Further research is needed to investigate whether or how a favorable lifestyle modifies this intrinsic capacity to resist diseases, and if the impacts of lifestyle behavior on health differs due to genetic predisposition for muscle strength.

Investigating resilience through intrinsic capacity networks in older adults.

BACKGROUND: The network approach may provide a framework for understanding intrinsic capacity (IC) as a system underlying functioning. The system's resilience to resist functional decline may arise from the interrelationships among system components, i.e., body functions or capacities. We applied network analysis to investigate whether the interplay between different intrinsic capacities differs according to age and self-rated health (SRH) in older adults. METHODS: The study sample consisted of a population-based cohort of community-dwelling older adults aged 75, 80, and 85 years (men n=356 and women n=469). We quantified five IC domains: vitality, locomotion, cognition, psychology, and sensory, using performance-based measurements and questionnaires, and estimated IC networks for two age (75- vs. 80- and 85-years) and SRH (higher vs. lower) groups separately for sexes. Differences in global network properties (e.g., density, overall connectivity) and centrality indices were compared between the groups. RESULTS: IC network density (i.e., the number of edges) was higher in the 80- and 85-olds compared to the 75-year-olds, and in the worse compared to the better SRH group in both sexes. However, the differences in edge weights and global strength of the networks were statistically non-significant. Walking speed was the most central node in the estimated networks. CONCLUSIONS: With increasing age and health decline, the IC network seems to become more denser, which may indicate a loss of system resilience. Walking is a more complex activity than the others requiring the functioning of many subsystems, which may explain why it connects multiple domains in the IC network.

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.

Intrinsic capacity: an under-researched concept in geriatrics.

In 2015, the World Health Organisation (WHO) introduced the concept of intrinsic capacity (IC) as part of a new public health model for healthy ageing. IC refers to the overall combination of an individual's physical and mental capacities, and is promoted as a new positive approach to the health and wellbeing of older adults. However, there is still insufficient evidence that implementing IC leads to better care for older adults. Moreover, the current operationalisations of IC lead to confusion and redundant research. In this commentary, we discuss whether the concept of IC has added value for geriatrics, and describe the main issues related to its conceptualisation, measurement, and application. We argue that there is a need to clarify and validate the concept of IC, including independent evidence regarding its feasibility and acceptance in clinical practice.

Autonomic nervous system and postural control regulation during orthostatic test as putative markers of physical resilience among community-dwelling older adults.

INTRODUCTION: We examined whether autonomic nervous system (ANS) and postural control regulation during orthostatic test reflect physical resilience by studying their associations with maximal walking speed and mortality. METHODS: The participants were community-dwelling Finnish men (n = 303) and women (n = 386) aged 75, 80, and 85 years at baseline. Systolic and diastolic blood pressure (BP), heart rate, heart rate variability (HRV), respiratory rate, and postural sway were obtained using a digital sphygmomanometer, a single-channel ECG, and thigh- and chest-worn accelerometers. Linear and Cox regression models were used to estimate the associations of the physiological indices with maximal 10-m walking speed and 5-year mortality separately for sexes. RESULTS: Better maintenance of BP under orthostatic stress was associated with faster walking speed in women and lower mortality hazard in men. Greater HRV in terms of low frequency power and lower respiration rate in supine position and smaller orthostatic changes in these were associated with faster walking speed especially in women. Less postural sway after standing up was associated with faster walking speed in women (-0.057, SE 0.022, p = 0.011) and more postural sway with increased mortality hazard in men (HR 1.71, 95 % CI 1.20-2.43) even after controlling for BP responses. CONCLUSIONS: In addition to ANS regulation at rest and under stress, adaptation of postural control system to orthostasis may be used in quantifying older adults' physical resilience. Wearable sensors capturing stimulus-response patterns and natural fluctuations of body functions may provide opportunities to monitor and incorporate different subsystems' resilience also in free-living conditions.

Development and validation of an intrinsic capacity composite score in the Longitudinal Aging Study Amsterdam: a formative approach.

BACKGROUND: Intrinsic capacity (IC) defined by the WHO refers to the composite of five domains of capacities. So far, developing and validating a standardized overall score of the concept have been challenging partly because its conceptual framework has been unclear. We consider that a person's IC is determined by its domain-specific indicators suggesting a formative measurement model. AIMS: To develop an IC score applying a formative approach and assess its validity. METHODS: The study sample (n = 1908) consisted of 57-88-year-old participants from the Longitudinal Aging Study Amsterdam (LASA). We used logistic regression models to select the indicators to the IC score with 6-year functional decline as an outcome. An IC score (range 0-100) was constructed for each participant. We examined the known-groups' validity of the IC score by comparing groups based on age and number of chronic diseases. The criterion validity of the IC score was assessed with 6-year functional decline and 10-year mortality as outcomes. RESULTS: The constructed IC score included seven indicators covering all five domains of the construct. The mean IC score was 66.7 (SD 10.3). The scores were higher among younger participants and those who had lower number of chronic diseases. After adjustment for sociodemographic indicators, chronic diseases, and BMI, a one-point higher IC score was associated with a 7% decreased risk for 6-year functional decline and a 2% decreased risk for 10-year mortality. CONCLUSIONS: The developed IC score demonstrated discriminative ability according to age and health status and is associated with subsequent functional decline and mortality.

Association Between Free-Living Sit-to-Stand Transition Characteristics, and Lower-Extremity Performance, Fear of Falling, and Stair Negotiation Difficulties Among Community-Dwelling 75 to 85-Year-Old Adults.

BACKGROUND: Good sit-to-stand (STS) performance is an important factor in maintaining functional independence. This study investigated whether free-living STS transition volume and intensity, assessed by a thigh-worn accelerometer, is associated with characteristics related to functional independence. METHODS: Free-living thigh-worn accelerometry was recorded continuously for 3-7 days in a population-based sample of 75-, 80-, and 85-year-old community-dwelling people (479 participants; women n = 287, men n = 192). The records were used to evaluate the number and intensity (angular velocity of the STS phase) of STS transitions. Associations with short physical performance battery (SPPB), 5-times-sit-to-stand test (5×STS), isometric knee extension force, self-reported fear of falls, and self-reported difficulty in negotiating stairs were also assessed. RESULTS: The number of STS transitions, mean and maximal angular velocity were lower in older age groups (p < .05). All variables were higher in men than in women (p < .001) and were positively associated with SPPB total points, knee extension force (r ranged from 0.18 to 0.39, all p < .001) and negatively associated with 5×STS (r = -0.13 - -0.24, all p < .05), lower extremity functional limitations (p < .01), fear of falls (p < .01), and stair negotiation difficulties (p < .01). CONCLUSIONS: Free-living STS characteristics were related to lower-extremity performance, lower extremity functional limitations, self-reported fear of falls, and stair negotiation difficulties, which can be a sensitive indicator of impending functional decline. Moreover, STS transitions may provide an indicator of adequacy of lower-limb muscle strength among older individuals.

Is Complexity of Daily Activity Associated with Physical Function and Life-Space Mobility among Older Adults?

PURPOSE: Information about mobility and physical function may be encoded in the complexity of daily activity pattern. Therefore, daily activity pattern complexity metrics could provide novel insight into the relationship between daily activity behavior and health. The purpose of the present study was to examine the association between the complexity of daily activity behavior and the mobility and physical function among community-dwelling older adults 75, 80, and 85 yr of age. METHODS: A total of 309 participants wore accelerometers concurrently on the thigh and the trunk for at least three consecutive days. Five activity states (lying, sitting, standing, walking, or activity other than walking) were defined in three different temporal grains (5 s, 1 min, and 5 min), and Lempel-Ziv complexity was evaluated. We assessed complexity of daily activity behavior using the life-space mobility and physical function with distance in preferred pace 6-min walk and the Short Physical Performance Battery. RESULTS: Weak positive associations were observed between the complexity of daily activity and the mobility and physical function at the finest temporal grains in both sexes (Spearman rho = 0.19 to 0.27, P < 0.05). No significant associations were observed in the coarsest temporal grain in either sex. CONCLUSIONS: Lempel-Ziv estimates of daily activity complexity with a fine temporal grain seem to be associated with community-dwelling older adults' physical function. The coarsest 5-min temporal grain may have smoothed out physiologically meaningful short activity bouts. Because complexity encodes information related to timing, intensity, and patterning of behavior, complexity of activity could be an informative indicator of future physical function and mobility.

Impact of mobility restrictions on active aging; cross-sectional associations and longitudinal changes parallel to COVID-19 restrictions.

BACKGROUND: Meaningful activities can be done in or around home, but opportunities for participation and active aging decrease when moving in smaller areas. Active aging refers to having an active approach to life in line with one's goals, ability and opportunities. In adults over 75 years with different baseline neighborhood mobility levels, we studied active aging scores two years prior to and amid COVID-19, when governments restricted mobility of residents to slow the COVID-19 outbreak. METHODS: AGNES cohort data were collected in 2017-2018 and spring 2020. Individuals were queried about their will, ability, and opportunity, and extent of doing 17 activities, and subsequently, item, composite and sub-scores of active aging were computed. Neighborhood mobility was assessed as frequency of moving in or beyond own neighborhood (limited, regular, daily=reference). Associations were studied using Generalized Linear Models (cross-sectionally, n = 1007) and General Estimating Equations (prospectively, n = 774). RESULTS: Participants with limited baseline neighborhood mobility had lower active aging scores than those with daily mobility, but the decline over time was similar. Some item scores on opportunity to act and extent of doing, e.g. for making one's day more interesting and advancing matters of faith or worldview, were better retained amid COVID-19 by those with limited mobility, attenuating group differences. CONCLUSIONS: Active aging scores were somewhat compromised in individuals with limited neighborhood mobility, but opportunities for and engagement in several activities seemed to be better retained amid COVID-19 than for those with daily mobility. Thus, active aging may be possible despite mobility restriction.

Maintenance of high quality of life as an indicator of resilience during COVID-19 social distancing among community-dwelling older adults in Finland.

PURPOSE: Social distancing during the COVID-19 pandemic reduced possibilities for activities of choice potentially threatening quality of life (QoL). We defined QoL resilience as maintaining high quality of life and studied whether walking speed, absence of loneliness, living arrangement, and stress-coping ability predict QoL resilience among older people. METHODS: Community-dwelling 75-, 80-, and 85-year-old persons (n = 685) were interviewed and examined in 2017-2018 and were followed up during COVID-19 social distancing in 2020. We assessed QoL using the OPQOL-brief scale and set a cut-off for 'constant high' based on staying in the highest baseline quartile over the follow-up and categorized all others as having 'low/moderate'. Perceived restrictiveness of the social distancing recommendations was examined with one item and was categorized as 'yes' or 'no' restrictiveness. RESULTS: Better stress-coping ability (OR 1.21, 95% CI 1.14-1.28) and not being lonely (OR 2.67, 95% CI 1.48-4.63) increased the odds for constant high QoL from before to amid social distancing, and the odds did not differ according to the perceived restrictiveness of the social distancing recommendations. Higher walking speed predicted constant high QoL only among those perceiving restrictiveness (OR 1.16, 95% CI 1.07-1.27). Living arrangement did not predict constant high QoL. CONCLUSION: During social distancing, psychosocial resources helped to maintain good QoL regardless how restrictive the social distancing recommendations were perceived to be. Better physical capacity was important for constant high QoL only among those perceiving restrictiveness presumably because it enabled replacing blocked activities with open outdoor physical activities.

Day-to-Day Variability and Year-to-Year Reproducibility of Accelerometer-Measured Free-Living Sit-to-Stand Transitions Volume and Intensity among Community-Dwelling Older Adults.

(1) Background: The purpose of this study was to evaluate the day-to-day variability and year-to-year reproducibility of an accelerometer-based algorithm for sit-to-stand (STS) transitions in a free-living environment among community-dwelling older adults. (2) Methods: Free-living thigh-worn accelerometry was recorded for three to seven days in 86 (women n = 55) community-dwelling older adults, on two occasions separated by one year, to evaluate the long-term consistency of free-living behavior. (3) Results: Year-to-year intraclass correlation coefficients (ICC) for the number of STS transitions were 0.79 (95% confidence interval, 0.70-0.86, p < 0.001), for mean angular velocity-0.81 (95% ci, 0.72-0.87, p < 0.001), and maximal angular velocity-0.73 (95% ci, 0.61-0.82, p < 0.001), respectively. Day-to-day ICCs were 0.63-0.72 for number of STS transitions (95% ci, 0.49-0.81, p < 0.001) and for mean angular velocity-0.75-0.80 (95% ci, 0.64-0.87, p < 0.001). Minimum detectable change (MDC) was 20.1 transitions/day for volume, 9.7°/s for mean intensity, and 31.7°/s for maximal intensity. (4) Conclusions: The volume and intensity of STS transitions monitored by a thigh-worn accelerometer and a sit-to-stand transitions algorithm are reproducible from day to day and year to year. The accelerometer can be used to reliably study STS transitions in free-living environments, which could add value to identifying individuals at increased risk for functional disability.

Psychometric properties of the 10-item Connor-Davidson resilience scale among Finnish older adults.

OBJECTIVES: Resilience, the ability to bounce back after adverse events may be an important factor in active aging. The 10-item version of the Connor-Davidson Resilience Scale (CD-RISC10) seems suitable for aging research owing to its low participant burden; however, its psychometric properties have not been comprehensively reported for older people. For example, no estimate exists of the test-retest reliability of the scale when used with older adults. Hence, this study evaluated the psychometric properties of the CD-RISC10 in a large population-based sample of community-dwelling older people. METHOD: The scale's internal consistency, factor structure, construct validity, test-retest reliability, and user experience were analyzed among 1018 Finnish older adults (57% women) aged 75 (45%), 80 (33%) and 85 years (22%). RESULTS: The internal consistency of the CD-RISC10 was good (Cronbach's α = 0.85), test-retest reliability moderate (ICC = 0.61), and the scale was unidimensional. However, a two-factor solution was found among the 75-year-olds, where the ability to deal positively with change (e.g. using humor) explained an additional part of resilience. While no differences by gender, age, or education were observed in total scores, very good perceived financial situation was associated with higher resilience. The scale showed good construct validity, and user feedback indicated that administering the scale in research is quick and easy. CONCLUSION: In general, the CD-RISC10 is a valid method to study older adults' psychological resilience. However, the present test-retest reliability values suggest caution in using the scale as an outcome measure in intervention studies.

Birth cohort differences in cognitive performance in 75- and 80-year-olds: a comparison of two cohorts over 28 years.

OBJECTIVE: To evaluate cohort differences in cognitive performance in older men and women born and assessed 28 years apart. METHODS: Data in this study were drawn from two age-homogeneous cohorts measured in the same laboratory using the same standardized cognitive performance tests. Participants in the first cohort were born in 1910 and 1914 and assessed in 1989-1990 (Evergreen project, n = 500). Participants in the second cohort were born in 1938 or 1939 and 1942 or 1943 and assessed in 2017-2018 (Evergreen II, n = 726). Participants in both cohorts were assessed at age 75 and 80 years and were recruited from the population register. Cognitive performance was measured using the Digit Span test from the Wechsler Memory Scale (WMS), Digit Symbol test from the Wechsler Adult Intelligence Scale (WAIS) and phonemic Verbal Fluency test from the Schaie-Thurstone Adult Mental Abilities Test. Reaction time assessing motor and mental responses was measured with a simple finger movement task, followed by a complex finger movement task. T-tests were used to study cohort differences and linear regression models to study possible factors underlying differences. RESULTS: We found statistically significant cohort differences in all the cognitive performance tests, except for the digit span test and simple movement task in men, the later-born cohort performing better in all the measured outcomes. CONCLUSIONS: The results of this study provide strong evidence that cognitive performance is better in more recent cohorts of older people compared to their counterparts measured 28 years earlier.

Cohort Differences in Maximal Physical Performance: A Comparison of 75- and 80-Year-Old Men and Women Born 28 Years Apart.

BACKGROUND: Whether increased life expectancy is accompanied by increased functional capacity in older people at specific ages is unclear. We compared similar validated measures of maximal physical performance in 2 population-based older cohorts born and assessed 28 years apart. METHOD: Participants in the first cohort were born in 1910 and 1914 and were assessed at age 75 and 80 years, respectively (N = 500, participation rate 77%). Participants in the second cohort were born in 1938 or 1939 and 1942 or 1943 and were assessed at age 75 and 80 years, respectively (N = 726, participation rate 40%). Participants were recruited using a population register and all community-dwelling persons in the target area were eligible. Both cohorts were interviewed at home and were examined at the research center with identical protocols. Maximal walking speed, maximal isometric grip and knee extension strength, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were assessed. Data on non-participation were systematically collected. RESULTS: Walking speed was on average 0.2-0.4 m/s faster in the later than earlier cohort. In grip strength, the improvements were 5%-25%, and in knee extension strength 20%-47%. In FVC, the improvements were 14-21% and in FEV1, 0-14%. CONCLUSIONS: The later cohort showed markedly and meaningfully higher results in the maximal functional capacity tests, suggesting that currently 75- and 80-year-old people in Finland are living to older ages nowadays with better physical functioning.

Living alone vs. living with someone as a predictor of mortality after a bone fracture in older age.

BACKGROUND: Living alone is a risk factor for health decline in old age, especially when facing adverse events increasing vulnerability. AIM: We examined whether living alone is associated with higher post-fracture mortality risk. METHODS: Participants were 190 men and 409 women aged 75 or 80 years at baseline. Subsequent fracture incidence and mortality were followed up for 15 years. Extended Cox regression analysis was used to compare the associations between living arrangements and mortality risk during the first post-fracture year and during the non-fracture time. All participants contributed to the non-fracture state until a fracture occurred or until death/end of follow-up if they did not sustain a fracture. Participants who sustained a fracture during the follow-up returned to the non-fracture state 1 year after the fracture unless they died or were censored due to end of follow-up. RESULTS: Altogether, 22% of men and 40% of women sustained a fracture. During the first post-fracture year, mortality risk was over threefold compared to non-fracture time but did not differ by living arrangement. In women, living alone was associated with lower mortality risk during non-fracture time, but the association attenuated after adjustment for self-rated health. In men, living alone was associated with increased mortality risk during non-fracture time, although not significantly. CONCLUSION: The results suggest that living alone is not associated with pronounced mortality risk after a fracture compared to living with someone.

Mortality Risk Among Older People Who Did Versus Did Not Sustain a Fracture: Baseline Prefracture Strength and Gait Speed as Predictors in a 15-Year Follow-Up.

BACKGROUND: Physiological reserve, as indicated by muscle strength and gait speed, may be especially determinant of survival in people who are exposed to a health stressor. We studied whether the association between strength/speed and mortality risk would be stronger in the time period after a fracture compared to other time periods. METHODS: Participants were population-based sample of 157 men and 325 women aged 75 and 80 years at baseline. Maximal 10-m gait speed and maximal isometric grip and knee extension strength were tested at the baseline before the fracture. Subsequent fracture incidence and mortality were followed up for 15 years. Cox regression analysis was used to estimate fracture time-stratified effects of gait speed and muscle strength on mortality risk in three states: (i) nonfracture state, (ii) the first postfracture year, and (iii) after the first postfracture year until death/end of follow-up. RESULTS: During the follow-up, 20% of the men and 44% of the women sustained a fracture. In both sexes, lower gait speed and in women lower knee extension strength was associated with increased mortality risk in the nonfracture state. During the first postfracture year, the mortality risk associated with slower gait and lower strength was increased and higher than in the nonfracture state. After the first postfracture year, mortality risk associated with lower gait speed and muscle strength attenuated. CONCLUSIONS: Lower gait speed and muscle strength were more strongly associated with mortality risk after fracture than during nonfracture time, which may indicate decreased likelihood of recovery.