Neighborhood Walkability, Walking Difficulties, and Participation in Leisure Activities Among Older People: A Cross-Sectional Study and 4-Year Follow-Up of a Subsample.

Objectives: To study cross-sectional and longitudinal associations between objectively assessed neighborhood walkability, walking difficulties, and participation in leisure activities among older people. Methods: Self-reported 2 km walking difficulty (intact, modifications, difficulties) at baseline and participating in organized group, outdoor recreation and cultural activities at baseline and follow-up were studied in community-dwelling persons (N = 848) aged 75-90. A walkability index, calculated using a geographic information system, was categorized into tertiles (lowest, middle, highest). Results: Residence in the highest walkability areas was associated with higher participation in cultural activities and lower participation in outdoor recreation, while the latter was most frequently reported by residents in the lowest walkability areas. Those reporting no difficulties were more likely than those reporting difficulties to participate in all studied activities. Residence in the middle or highest walkability areas predicted higher participation in cultural activities at follow-up. Discussion: Older persons activity profiles associate with neighborhood walkability and walking difficulties.

Mortality Associations With DNA Methylation-Based Biological Aging and Physical Functioning Measures Across a 20-Year Follow-up Period.

BACKGROUND: Measures of biological aging range from DNA methylation (DNAm)-based estimates to measures of physical abilities. The purpose of this study was to compare DNAm- and physical functioning-based measures of biological aging in predicting mortality. METHODS: We studied 63- to 76-year-old women (N = 395) from the Finnish Twin Study on Aging (FITSA). Participants' biological age (epigenetic clocks DNAm GrimAge and DunedinPACE) was estimated using blood DNAm data. Tests of physical functioning conducted under standardized laboratory conditions included the Timed Up and Go (TUG) test and 10-m walk test. Mortality hazard ratios were calculated per every 1 standard deviation (SD) increase in the predictor. Cox regression models were conducted for individuals and twin pairs, the latter controlling for underlying genetic effects. The models were adjusted for known lifestyle predictors of mortality. RESULTS: During the follow-up period (mean 17.0 years, range 0.2-20.3), 187 participants died. In both the individual-based and pairwise analyses, GrimAge and both functional biomarkers of aging were associated with mortality independent of family relatedness, chronological age, physical activity, body mass index, smoking, education, or chronic diseases. In a model including both the DNAm-based measures and functional biomarkers of aging, GrimAge and TUG remained predictive. CONCLUSIONS: The findings suggest that DNAm GrimAge and the TUG test are strong predictors of mortality independent of each others and genetic influences. DNAm-based measures and functional tests capture different aspects of the aging process and thus complement each other as measures of biological aging in predicting mortality.

A Polygenic Risk Score for Hand Grip Strength Predicts Muscle Strength and Proximal and Distal Functional Outcomes among Older Women.

PURPOSE: Hand grip strength (HGS) is a widely used indicator of overall muscle strength and general health. We computed a polygenic risk score (PRS) for HGS and examined whether it predicted muscle strength, functional capacity, and disability outcomes. METHODS: Genomewide association study summary statistics for HGS from the Pan-UK Biobank was used. PRS were calculated in the Finnish Twin Study on Aging ( N = 429 women, 63-76 yr). Strength tests included HGS, isometric knee extension, and ankle plantarflexion strength. Functional capacity was examined with the Timed Up and Go, 6-min and 10-m walk tests, and dual-task tests. Disabilities in the basic activities of daily living (ADL) and instrumental ADL (IADL) were investigated with questionnaires. The proportion of variation in outcomes accounted for by PRS HGS was examined using linear mixed models and extended logistic regression. RESULTS: The measured HGS increased linearly over increasing PRS ( ß = 4.8, SE = 0.93, P < 0.001). PRS HGS independently accounted for 6.1% of the variation in the measured HGS ( ß = 14.2, SE = 3.1, P < 0.001), 5.4% of the variation in knee extension strength ( ß = 19.6, SE = 4.7, P < 0.001), 1.2% of the variation in ankle plantarflexion strength ( ß = 9.4, SE = 4.2, P = 0.027), and 0.1%-1.5% of the variation in functional capacity tests ( P = 0.016-0.133). Further, participants with higher PRS HGS were less likely to have ADL/IADL disabilities (odds ratio = 0.74-0.76). CONCLUSIONS: Older women with genetic risk for low muscle strength were significantly weaker than those with genetic susceptibility for high muscle strength. PRS HGS was also systematically associated with overall muscle strength and proximal and distal functional outcomes that require muscle strength.

The Association Between Epigenetic Clocks and Physical Functioning in Older Women: A 3-Year Follow-up.

BACKGROUND: Epigenetic clocks are composite markers developed to predict chronological age or mortality risk from DNA methylation (DNAm) data. The present study investigated the associations between 4 epigenetic clocks (Horvath's and Hannum's DNAmAge and DNAm GrimAge and PhenoAge) and physical functioning during a 3-year follow-up. METHOD: We studied 63- to 76-year-old women (N = 413) from the Finnish Twin Study on Aging. DNAm was measured from blood samples at baseline. Age acceleration (AgeAccel), that is, discrepancy between chronological age and DNAm age, was determined as residuals from linear model. Physical functioning was assessed under standardized laboratory conditions at baseline and at follow-up. A cross-sectional analysis was performed with path models, and a longitudinal analysis was conducted with repeated measures linear models. A nonrandom missing data analysis was performed. RESULTS: In comparison to the other clocks, GrimAgeAccel was more strongly associated with physical functioning. At baseline, GrimAgeAccel was associated with lower performance in the Timed Up and Go (TUG) test and the 6-minute walk test. At follow-up, significant associations were observed between GrimAgeAccel and lowered performance in the TUG, 6-minute and 10-m walk tests, and knee extension and ankle plantar flexion strength tests. CONCLUSIONS: The DNAm GrimAge, a novel estimate of biological aging, associated with decline in physical functioning over the 3-year follow-up in older women. However, associations between chronological age and physical function phenotypes followed similar pattern. Current epigenetic clocks do not provide strong benefits in predicting the decline of physical functioning at least during a rather short follow-up period and restricted age range.

Perceived Opportunities for Physical Activity and Willingness to Be More Active in Older Adults with Different Physical Activity Levels.

This study examined equity in physical activity (PA) by investigating whether perceived opportunity for PA was associated with willingness to be more active. Among community residents (75, 80, or 85 years old, n = 962) perceived opportunity for PA (poor and good), willingness to be more active (not at all, a bit, and a lot), and level of PA (low, moderate, and high) were assessed via questionnaires. Multinomial logistic regression showed that physical activity moderated the association between poor opportunity and willingness to increase PA. Among those with moderate PA, poor opportunity for PA increased the odds of willingness to be a lot more active (multinomial odds ratio, mOR 3.90, 95% confidence interval 2.21-6.87) than not wanting to be more active compared to those perceiving good opportunities. Associations were similar at high PA levels (p < 0.001), but were not found at low PA levels. Those with moderate or high PA wish to increase their activity particularly when the perceived opportunities for activity are not optimal. Among those with low PA, perceived opportunities are not associated with a perceived need to increase physical activity. Increasing equity in physical activity in old age requires provision of support and opportunities at every level of physical activity.

Does the epigenetic clock GrimAge predict mortality independent of genetic influences: an 18 year follow-up study in older female twin pairs.

BACKGROUND: Epigenetic clocks are based on DNA methylation (DNAm). It has been suggested that these clocks are useable markers of biological aging and premature mortality. Because genetic factors explain variations in both epigenetic aging and mortality, this association could also be explained by shared genetic factors. We investigated the influence of genetic and lifestyle factors (smoking, alcohol consumption, physical activity, chronic diseases, body mass index) and education on the association of accelerated epigenetic aging with mortality using a longitudinal twin design. Utilizing a publicly available online tool, we calculated the epigenetic age using two epigenetic clocks, Horvath DNAmAge and DNAm GrimAge, in 413 Finnish twin sisters, aged 63-76 years, at the beginning of the 18-year mortality follow-up. Epigenetic age acceleration was calculated as the residuals from a linear regression model of epigenetic age estimated on chronological age (AAHorvath, AAGrimAge, respectively). Cox proportional hazard models were conducted for individuals and twin pairs. RESULTS: The results of the individual-based analyses showed an increased mortality hazard ratio (HR) of 1.31 (CI95: 1.13-1.53) per one standard deviation (SD) increase in AAGrimAge. The results indicated no significant associations of AAHorvath with mortality. Pairwise mortality analyses showed an HR of 1.50 (CI95: 1.02-2.20) per 1 SD increase in AAGrimAge. However, after adjusting for smoking, the HR attenuated substantially and was statistically non-significant (1.29; CI95: 0.84-1.99). Similarly, in multivariable adjusted models the HR (1.42-1.49) was non-significant. In AAHorvath, the non-significant HRs were lower among monozygotic pairs in comparison to dizygotic pairs, while in AAGrimAge there were no systematic differences by zygosity. Further, the pairwise analysis in quartiles showed that the increased within pair difference in AAGrimAge was associated with a higher all-cause mortality risk. CONCLUSIONS: In conclusion, the findings suggest that DNAm GrimAge is a strong predictor of mortality independent of genetic influences. Smoking, which is known to alter DNAm levels and is built into the DNAm GrimAge algorithm, attenuated the association between epigenetic aging and mortality risk.

Outdoor Mobility and Use of Adaptive or Maladaptive Walking Modifications Among Older People.

BACKGROUND: In old age, decline in functioning may cause changes in walking ability. Our aim was to study whether older people who report adaptive, maladaptive, or no walking modifications differ in outdoor mobility. METHODS: Community-dwelling people aged 75-90 years (N = 848) were interviewed at baseline, of whom 761 participated in the 2-year follow-up. Walking modifications were assessed by asking the participants whether they had modified their way of walking 2 km due to their health. Based on the responses, three categories were formed: no walking modifications (reference), adaptive (eg, walking more slowly, using an aid), and maladaptive walking modifications (reduced frequency of walking, or having given up walking 2 km). Differences between these categories in life-space mobility, autonomy in participation outdoors, and unmet physical activity need were analyzed using generalized estimation equation models. RESULTS: Participants with maladaptive walking modifications (n = 238) reported the most restricted life-space mobility (ß = -9.6, SE = 2.5, p < .001) and autonomy in participation outdoors (ß = 1.7, SE = 0.6, p = .004) and the highest prevalence of unmet physical activity need (odds ratio = 4.3, 95% confidence interval = 1.1-16.5) at baseline and showed a decline in these variables over time. Those with no walking modifications (n = 285) at baseline exhibited the best values in all outdoor mobility variables and no change over time. Although at baseline those with adaptive walking modifications (n = 325) resembled those with no modifications, their outdoor mobility declined over time. CONCLUSION: Adopting adaptive modifications may postpone decline in outdoor mobility, whereas the use of maladaptive modifications has unfavorable consequences for outdoor mobility.

The Relationship Between Sleep Characteristics and Unmet Physical Activity Need in Older Women.

Objective: We examined among older women the association of sleep quality, daytime tiredness, and sleep duration with unmet physical activity need, that is, wishing to be more physically active but perceiving no opportunity for it. Method: Cross-sectional logistic regression analyses among women aged 74 to 86 years (Finnish Twin Study on Aging, third wave, n = 302). Results: Thirty-one participants reported unmet physical activity need. Short sleepers had fivefold and long sleepers threefold odds for unmet physical activity need compared with normative sleepers, while for daytime tiredness the odds were double. Presence of daytime tiredness and unmet physical activity coincided with higher prevalence of chronic diseases, depressive symptoms and walking difficulties, which partly explains the observed associations. Poor sleep quality was not associated with unmet physical activity need. Discussion: Older women with nonoptimal sleep characteristics who perceive unmet physical activity need may benefit from solutions that improve their perceived opportunities for physical activity.

Neighborhood Mobility and Unmet Physical Activity Need in Old Age: A 2-Year Follow-Up.

BACKGROUND: Many older people report a willingness to increase outdoor physical activity (PA), but no opportunities for it, a situation termed as unmet PA need. The authors studied whether lower neighborhood mobility and PA precede the development of unmet PA need. METHODS: Community-dwelling 75- to 90-year-old people (n = 700) were interviewed annually for 2 years. Unmet PA need, neighborhood mobility, and PA were self-reported. In addition, accelerometer-based step counts were assessed among a subgroup (n = 156). RESULTS: Logistic regression analyses revealed that lower baseline neighborhood mobility (odds ratio 3.02, 95% confidence interval [1.86, 4.90] vs. daily) and PA (odds ratio 4.37, 95% confidence interval [2.62, 7.29] vs. high) were associated with the development of unmet PA need over 2 years. The participants with higher step counts had a lower risk for unmet PA need (odds ratio 0.68, 95% confidence interval, [0.54, 0.87]). CONCLUSION: Maintaining higher PA levels and finding solutions for daily outdoor mobility, especially for those with declines in health, may protect from the development of unmet PA need.

The Older Finnish Twin Cohort - 45 Years of Follow-up.

The older Finnish Twin Cohort (FTC) was established in 1974. The baseline survey was in 1975, with two follow-up health surveys in 1981 and 1990. The fourth wave of assessments was done in three parts, with a questionnaire study of twins born during 1945-1957 in 2011-2012, while older twins were interviewed and screened for dementia in two time periods, between 1999 and 2007 for twins born before 1938 and between 2013 and 2017 for twins born in 1938-1944. The content of these wave 4 assessments is described and some initial results are described. In addition, we have invited twin-pairs, based on response to the cohortwide surveys, to participate in detailed in-person studies; these are described briefly together with key results. We also review other projects based on the older FTC and provide information on the biobanking of biosamples and related phenotypes.

Hearing in Real-Life Environments (HERE): Structure and Reliability of a Questionnaire on Perceived Hearing for Older Adults.

OBJECTIVES: The ability to hear in a variety of social situations and environments is vital for social participation and a high quality of life. One way to assess hearing ability is by means of self-report questionnaire. For questionnaires to be useful, their measurement properties, based on careful validation, have to be known. Only recently has consensus been reached concerning how to perform such validation and been published as COSMIN (consensus-based standards for the selection of health status measurement instruments) guidelines. Here the authors use these guidelines to evaluate the measurement properties of the "Hearing in Real-Life Environments" (HERE) questionnaire, a newly developed self-report measure that assesses speech perception, spatial orientation, and the social-emotional consequences of hearing impairment in older adults. The aim is to illustrate the process of validation and encourage similar examinations of other frequently used questionnaires. DESIGN: The HERE questionnaire includes 15 items with a numeric rating scale from 0 to 10 for each item and allows the assessment of hearing with and without hearing aids. The evaluation was performed in two cohorts of community-dwelling older adults from Finland (n = 581, mean 82 years) and the United Kingdom (n = 50, mean 69 years). The internal structure of the questionnaire and its relationship to age, hearing level, and self-reported and behavioral measures of speech perception was assessed and, when possible, compared between cohorts. RESULTS: The results of the factor analysis showed that the HERE's internal structure was similar across cohorts. In both cohorts, the factor analysis showed a satisfactory solution for three factors (speech hearing, spatial hearing, and socio-emotional consequences), with a high internal consistency for each factor (Cronbach's α's for the factors from 0.90 to 0.97). Test-retest analysis showed the HERE overall mean score to be stable and highly replicable over time (intraclass correlation coefficient = 0.86, standard error of measurement of the test score = 0.92). The HERE overall mean score correlated highly with another self-report measure of speech perception, the Speech Spatial Qualities of Hearing questionnaire (standardized regression coefficient [ß] = -0.75, p < 0.001), moderately highly with behaviorally assessed hearing level (best-ear average: ß = 0.45 to 0.46), and moderately highly with behaviorally measured intelligibility of sentences in noise (ß = -0.50, p < 0.001). CONCLUSIONS: Using the COSMIN guidelines, the authors show that the HERE is a valid, reliable, and stable questionnaire for the assessment of self-reported speech perception, sound localization, and the socio-emotional consequences of hearing impairment in the context of social functioning. The authors also show that cross-cultural data collected using different data collection strategies can be combined with a range of statistical methods to validate a questionnaire.

The effect of body mass index, lower extremity performance, and use of a private car on incident life-space restriction: a two-year follow-up study.

BACKGROUND: The purpose of the study was to explore the single and combined contributions of body mass index (BMI) and lower extremity performance as modifiable physical factors, and the influence of use of a private car as an environmental factor on prevalent and incident life-space restriction in community-dwelling older people. METHODS: Community-dwelling people aged 75-90 years (n = 823) participated in the Life-Space Mobility in Old Age (LISPE) two-year follow-up study. Participants who reported that the largest life-space area they had attained, without aid from any device or another person, was the neighborhood or less were considered to have life-space restriction. Incident life-space restriction was the endpoint of Cox's proportional hazard model. BMI, lower extremity performance (Short Physical Performance Battery, SPPB), and use of a private car were predictors. RESULTS: At baseline, people who had both obesity (BMI ≥30.0) and impaired lower extremity performance (SPPB 0-9) had a higher prevalence of life-space restriction (prevalence ratio 3.6, 95% confidence interval, CI, 2.0-6.3) compared to those with normal weight (BMI 23.0-24.9) and intact physical performance (SPPB 10-12). The 581 people without life-space restriction at the baseline contributed 1033 person-years during the two-year follow-up. Incident life-space restrictions were reported by 28.3% participants. A higher hazard ratio (HR) for incident life-space restriction was observed in subjects having both obesity and impaired lower extremity performance (HR 3.6, 95% CI, 1.7-7.4), impaired lower extremity performance only (HR 1.9, 95% CI 0.9-4.1), and obesity only (HR 1.8, 95% CI, 0.9-3.5) compared to those with normal weight and intact performance. Private car passengers (HR 2.0, 95% CI, 1.3-3.0) compared to car drivers had a higher risk of life-space restriction. All models were adjusted for age, sex, chronic diseases, and education. CONCLUSIONS: Older people with impaired lower extremity performance have an increased risk of incident life-space restriction especially if combined with obesity. Also, not driving a car renders older people vulnerable to life-space restriction.

The Combined Effect of Lower Extremity Function and Cognitive Performance on Perceived Walking Ability Among Older People: A 2-Year Follow-up Study.

Background: We studied the combined effects of cognitive performance and lower extremity function on self-reported walking modifications and walking difficulty and on self-reported walking difficulty incidence over a 2-year follow-up. Methods: A total of 848 community-dwelling older people aged 75-90 years participated at baseline, 816 at the 1-year follow-up, and 761 at the 2-year follow-up. Baseline lower extremity function was measured with the Short Physical Performance Battery (<10 vs. ≥10) and cognitive performance with the Mini-Mental State Examination (<24 vs. ≥24). Difficulty in walking 2 km was self-reported and categorized into no difficulties, no difficulties but walking modifications, and prevalent difficulties. Data were analyzed with multinomial and Cox regressions and a mediation analysis. Results: At baseline, 33% reported no walking difficulties, 25% walking modifications, and 42% walking difficulty. Poorer lower extremity function and lower cognition increased the odds for walking difficulty. For those with both, the odds were almost eightfold higher for walking difficulty and threefold higher for walking modifications compared with having neither. Poorer lower extremity function mediated the association between low cognition and poorer perceived walking ability. Of those with no walking difficulty at baseline, 31% developed walking difficulty during the follow-up, the risk being almost twofold higher among those with poorer lower extremity function at baseline (hazard ratio = 1.82, 95% confidence interval = 1.28-2.59). Conclusion: Older people with poorer lower extremity function and cognitive performance are likely to have walking difficulties, rendering them especially vulnerable to further disability. Cognitive performance should be considered in interventions aimed at preventing mobility disability.

Active aging - resilience and external support as modifiers of the disablement outcome: AGNES cohort study protocol.

BACKGROUND: Population aging increases the need for knowledge on positive aspects of aging, and contributions of older people to their own wellbeing and that of others. We defined active aging as an individual's striving for elements of wellbeing with activities as per their goals, abilities and opportunities. This study examines associations of health, health behaviors, health literacy and functional abilities, environmental and social support with active aging and wellbeing. We will develop and validate assessment methods for physical activity and physical resilience suitable for research on older people, and examine their associations with active aging and wellbeing. We will examine cohort effects on functional phenotypes underlying active aging and disability. METHODS: For this population-based study, we plan to recruit 1000 participants aged 75, 80 or 85 years living in central Finland, by drawing personal details from the population register. Participants are interviewed on active aging, wellbeing, disability, environmental and social support, mobility, health behavior and health literacy. Physical activity and heart rate are monitored for 7 days with wearable sensors. Functional tests include hearing, vision, muscle strength, reaction time, exercise tolerance, mobility, and cognitive performance. Clinical examination by a nurse and physician includes an electrocardiogram, tests of blood pressure, orthostatic regulation, arterial stiffness, and lung function, as well as a review of chronic and acute conditions and prescribed medications. C-reactive protein, small blood count, cholesterol and vitamin D are analyzed from blood samples. Associations of factors potentially underlying active aging and wellbeing will be studied using multivariate methods. Cohort effects will be studied by comparing test results of physical and cognitive functioning with results of a cohort examined in 1989-90. CONCLUSIONS: The current study will renew research on positive gerontology through the novel approach to active aging and by suggesting new biomarkers of resilience and active aging. Therefore, high interdisciplinary impact is expected. This cross-sectional study will not provide knowledge on temporal order of events or causality, but an innovative cross-sectional dataset provides opportunities for emergence of novel creative hypotheses and theories.

Hearing and Quality of Life Among Community-Dwelling Older Adults.

Objectives: Hearing loss is a common health concern in older people, and the prevalence of hearing loss increases with aging. Poor hearing may cause difficulties in everyday life situations and reduce quality of life (QoL). The aim of this study was to assess the associations between different domains of QoL (physical, psychological, social, and environmental), perceived hearing difficulties in various everyday situations, and audiometrically measured hearing level among community-dwelling older adults. Method: Cross-sectional analysis of 76- to 91-year-old community-dwelling adults. Data on QoL (WHO Quality of Life Assessment short version) and perceived hearing difficulties were gathered via postal questionnaires (n = 706) and screening pure-tone audiometry was performed at the participants' homes for a random subsample (n = 161). Data were analyzed with linear regression models. Results: Factor analysis on the perceived hearing difficulties questionnaire identified three dimensions: speech hearing, socioemotional effects, and spatial hearing. All the perceived hearing difficulty factors, but not the pure-tone audiometry results, were significantly associated with poorer values in all the QoL domains and the total QoL score. Discussion: Perceived hearing difficulties in various everyday life situations are more strongly associated with older adults' QoL than audiometrically assessed hearing impairment.

Perceived Benefit From Hearing Aid Use and Life-Space Mobility Among Community-Dwelling Older Adults.

OBJECTIVES: To examine the association between perceived benefit from hearing aid (HA) use and life-space mobility among older adults. METHOD: Cross-sectional analysis of 76- to 91-year-old community-dwelling adults ( n = 702). Data on perceived hearing with and without a HA were obtained via postal questionnaire and data on life-space mobility (Life-Space Assessment, range = 0-120) via phone interview. RESULTS: Participants who perceived more benefit from HA use, had a better life-space mobility score ( M = 65, SD = 2.6) than participants who had less benefit from using a HA ( M = 55, SD = 3.2). Participants who benefitted more from HA use did not differ from those who did not have a HA ( M = 63, SD = 0.9) in their life-space mobility score. DISCUSSION: Perceived benefit from HA use is associated with higher life-space mobility among community-dwelling older adults. Future studies are needed to examine whether use of an appropriate HA promotes life-space mobility among those with difficulties in hearing.

The Temporal Association Between Executive Function and Life-Space Mobility in Old Age.

Background: Life-space mobility, an indicator of community mobility, describes person's movements in terms of the distance from home, the frequency of movement, and the need of assistance for movement. Executive function (EF) is a higher-order cognitive function that supervises motor control and plays a key role in a person's ability to function independently. Cognitive impairment often co-occurs with restricted life-space mobility; however, the direction of the longitudinal associations between EF and life-space mobility is unclear. The aim of this study was to investigate the temporal associations between EF and life-space mobility among community-dwelling older people. Methods: One hundred eight community-dwelling persons aged 76 to 91 years participated in the 2 year follow-up study. EF was measured with the Trail Making Test. The Life-Space Assessment (range 0-120, higher scores indicate more mobility) was used to assess life-space mobility. Cross-lagged model design was used to examine longitudinal relationship between EF and life-space mobility. The model was adjusted for age and gender. Results: Average age of participants at baseline was 82.2 (SD 4.1) years and 59% were women. Better EF at baseline predicted higher life-space mobility at follow-up (path coefficient = 3.81, 95% confidential interval; 0.84, 6.78, p = .012), whereas baseline life-space mobility did not predict EF at follow-up. Conclusion: EF was a determinant of life-space mobility. Supporting EF may enhance maintaining independence and active participation in old age.

Executive function and life-space mobility in old age.

BACKGROUND: Life-space assessment incorporates all movements in terms of the distance from home, the frequency of movement and the need of assistance for movement. Executive function (EF) is an important higher order cognitive ability that controls and guides people's goal-directed actions. We examined the cross-sectional and longitudinal associations between EF and life-space mobility, and investigated if perceived walking difficulties, lower extremity performance, and transportation difficulties explain the association. METHODS: 157 community-dwelling persons aged 76-91 years participated in the study at the baseline, and 103 of them in 2-year follow-up study. Based on the distribution on the Trail Making Test participants were categorized into tertiles of EF. Life-space mobility was assessed using the Life-Space Assessment (range 0-120). Perceived walking difficulties and transportation difficulties were self-reported, and lower extremity performance was assessed with the short physical performance battery (SPPB). Adjustments were made for gender, age, number of chronic conditions, and years of education. RESULTS: Average age of participants at the baseline was 82.6 (SD 4.2) years and 61% were women. Individuals with poor EF had lower life-space mobility compared to those with good EF. SPPB and transportation difficulties explained the association. Over the 2-year follow-up, those with poor EF at the baseline showed steeper decline but the difference did not quite reach statistical significance (p = 0.068). CONCLUSIONS: People with better executive function had higher life-space mobility. This was explained by better lower extremity performance and absence of transportation difficulties. Cognitive decline may hinder access to community amenities, which in turn may further accelerate cognitive decline.

Task Modifications in Walking Postpone Decline in Life-Space Mobility Among Community-Dwelling Older People: A 2-year Follow-up Study.

BACKGROUND: Task modification refers to performing a task differently than before. While task modification in walking may be a sign of looming walking difficulty, it may also be adaptive in and postpone the decline in life-space mobility. However, this has not been studied. This study examined whether changes in life-space mobility over a 2-year period differ between people who at baseline report no walking difficulty and no task modification, those who report no walking difficulty but task modification, and those who report walking difficulty. METHODS: Community-dwelling people aged 75-90 years were interviewed face-to-face at baseline (N = 848), and over phone one (n = 816) and two (n = 761) years later. Life-space mobility was assessed annually with the Life-Space Assessment (range 0-120, higher scores indicate better life-space mobility). Self-reported ability to walk 2 km was assessed at baseline and categorized into "no difficulty," "no difficulty but task modifications" (reduced frequency, given up walking, walking slower or resting during walking) and "difficulty." The analyses were adjusted for age, gender, number of chronic conditions, cognitive impairment, lower extremity performance and education. RESULTS: The life-space mobility score was highest and remained stable over 2-years among those with no walking difficulties at baseline and lowest and showing a steady decline among those with walking difficulties. Those with task modifications formed the middle group. They showed no marked changes in life-space mobility during the first year, but significant decline during the second year. CONCLUSION: Task modifications in walking may help community-dwelling older people to postpone life-space mobility decline.