Large-scale assessment of physical activity in a population using high-resolution hip-worn accelerometry: the German National Cohort (NAKO).

Large population-based cohort studies utilizing device-based measures of physical activity are crucial to close important research gaps regarding the potential protective effects of physical activity on chronic diseases. The present study details the quality control processes and the derivation of physical activity metrics from 100 Hz accelerometer data collected in the German National Cohort (NAKO). During the 2014 to 2019 baseline assessment, a subsample of NAKO participants wore a triaxial ActiGraph accelerometer on their right hip for seven consecutive days. Auto-calibration, signal feature calculations including Euclidean Norm Minus One (ENMO) and Mean Amplitude Deviation (MAD), identification of non-wear time, and imputation, were conducted using the R package GGIR version 2.10-3. A total of 73,334 participants contributed data for accelerometry analysis, of whom 63,236 provided valid data. The average ENMO was 11.7 ± 3.7 mg (milli gravitational acceleration) and the average MAD was 19.9 ± 6.1 mg. Notably, acceleration summary metrics were higher in men than women and diminished with increasing age. Work generated in the present study will facilitate harmonized analysis, reproducibility, and utilization of NAKO accelerometry data. The NAKO accelerometry dataset represents a valuable asset for physical activity research and will be accessible through a specified application process.

Changes in physical activity and sedentary behavior during the first COVID-19 pandemic- restrictions in Germany: a nationwide survey : Running head: physical activity during the COVID-19 restrictions.

BACKGROUND: The COVID-19 pandemic restrictions posed challenges to maintaining healthy lifestyles and physical well-being. During the first mobility restrictions from March to mid-July 2020, the German population was advised to stay home, except for work, exercise, and essential shopping. Our objective was to comprehensively assess the impact of these restrictions on changes in physical activity and sedentary behavior to identify the most affected groups. METHODS: Between April 30, 2020, and May 12, 2020, we distributed a COVID-19-specific questionnaire to participants of the German National Cohort (NAKO). This questionnaire gathered information about participants' physical activity and sedentary behavior currently compared to the time before the restrictions. We integrated this new data with existing information on anxiety, depressive symptoms, and physical activity. The analyses focused on sociodemographic factors, social relationships, physical health, and working conditions. RESULTS: Out of 152,421 respondents, a significant proportion reported altered physical activity and sedentary behavioral patterns due to COVID-19 restrictions. Over a third of the participants initially meeting the WHO's physical activity recommendation could no longer meet the guidelines during the restrictions. Participants reported substantial declines in sports activities (mean change (M) = -0.38; 95% CI: -.390; -.378; range from -2 to + 2) and reduced active transportation (M = -0.12; 95% CI: -.126; -.117). However, they also increased recreational physical activities (M = 0.12; 95% CI: .117; .126) while engaging in more sedentary behavior (M = 0.24; 95% CI: .240; .247) compared to pre-restriction levels. Multivariable linear and log-binomial regression models indicated that younger adults were more affected by the restrictions than older adults. The shift to remote work, self-rated health, and depressive symptoms were the factors most strongly associated with changes in all physical activity domains, including sedentary behavior, and the likelihood to continue following the physical activity guidelines. CONCLUSIONS: Mobility patterns shifted towards inactivity or low-intensity activities during the nationwide restrictions in the spring of 2020, potentially leading to considerable and lasting health risks.

Framework and baseline examination of the German National Cohort (NAKO).

The German National Cohort (NAKO) is a multidisciplinary, population-based prospective cohort study that aims to investigate the causes of widespread diseases, identify risk factors and improve early detection and prevention of disease. Specifically, NAKO is designed to identify novel and better characterize established risk and protection factors for the development of cardiovascular diseases, cancer, diabetes, neurodegenerative and psychiatric diseases, musculoskeletal diseases, respiratory and infectious diseases in a random sample of the general population. Between 2014 and 2019, a total of 205,415 men and women aged 19-74 years were recruited and examined in 18 study centres in Germany. The baseline assessment included a face-to-face interview, self-administered questionnaires and a wide range of biomedical examinations. Biomaterials were collected from all participants including serum, EDTA plasma, buffy coats, RNA and erythrocytes, urine, saliva, nasal swabs and stool. In 56,971 participants, an intensified examination programme was implemented. Whole-body 3T magnetic resonance imaging was performed in 30,861 participants on dedicated scanners. NAKO collects follow-up information on incident diseases through a combination of active follow-up using self-report via written questionnaires at 2-3 year intervals and passive follow-up via record linkages. All study participants are invited for re-examinations at the study centres in 4-5 year intervals. Thereby, longitudinal information on changes in risk factor profiles and in vascular, cardiac, metabolic, neurocognitive, pulmonary and sensory function is collected. NAKO is a major resource for population-based epidemiology to identify new and tailored strategies for early detection, prediction, prevention and treatment of major diseases for the next 30 years.

Neighborhood environment, social participation, and physical activity in older adults with lower limb osteoarthritis: A mediation analysis.

Older adults with lower limb osteoarthritis (LLOA) are highly dependent on their physical and social environment for being physically active. Longitudinal data from 2286 older adults (Mage = 73.8 years; 50.3% female) in six European countries were analyzed using cross-lagged Structural Equation Modeling (SEM) and multi-group SEM. In cross-sectional analyses, neighborhood resources were associated with physical activity (r = 0.26;p < .001) and social participation (r = 0.13;p = .003). Physical activity at follow-up was associated with neighborhood resources, with this relationship mediated by social participation in people with LLOA (ß = 0.018;p = .013). To promote future physical activity, opportunities to socially engage in neighborhoods need to be targeted primarily to people with LLOA.

Perceptions of the Neighborhood Built Environment for Walking Behavior in Older Adults Living in Close Proximity.

Past research documents a discordance between perceived and objectively assessed neighborhood environmental features on walking behavior. Therefore, we examined differences in the perception of the same neighborhood built environment. Participants were grouped if they lived 400 m or closer to each other. The perception of the pedestrian infrastructure, neighborhood aesthetics, safety from crime, and safety from traffic was derived from a telephone survey from two North American metropolitan areas; 173 individuals were clustered into 42 groups. Older adults who walked for transport in their neighborhood experienced the same neighborhood as more walkable (ß = .19; p = .011) with better pedestrian infrastructure (ß = .16; p = .037). Older adults with physical limitations experienced the same neighborhood as less safe from crime (ß = -.17; p = .030) and traffic (ß = -.20; p = .009). The study supports the notion that individual behavior and physical restrictions alter the environment's perception and explains part of the discordance between objective and subjective assessment of the neighborhood environment.

Neighborhood Resources Associated With Active Travel in Older Adults-A Cohort Study in Six European Countries.

OBJECTIVES: To study associations between perceived neighborhood resources and time spent by older adults in active travel. METHODS: Respondents in six European countries, aged 65-85 years, reported on the perceived presence of neighborhood resources (parks, places to sit, public transportation, and facilities) with response options "a lot," "some," and "not at all." Daily active travel time (total minutes of transport-related walking and cycling) was self-reported at the baseline (n = 2,695) and 12-18 months later (n = 2,189). RESULTS: Reporting a lot of any of the separate resources (range B's = 0.19-0.29) and some or a lot for all four resources (B = 0.22, 95% confidence interval [0.09, 0.35]) was associated with longer active travel time than reporting none or fewer resources. Associations remained over the follow-up, but the changes in travel time were similar, regardless of the neighborhood resources. DISCUSSION: Perceiving multiple neighborhood resources may support older adults' active travel. Potential interventions, for example, the provision of new resources or increasing awareness of existing resources, require further study.

[Measuring physical fitness in the German National Cohort-methods, quality assurance, and first descriptive results]. / Messung der körperlichen Fitness in der NAKO Gesundheitsstudie ­ Methoden, Qualitätssicherung und erste deskriptive Ergebnisse.

Physical fitness is defined as an individual's ability to be physically active. The main components are cardiorespiratory fitness (CRF), muscle strength, and flexibility. Regardless of physical activity level, physical fitness is an important determinant of morbidity and mortality.The aim of the current study was to describe the physical fitness assessment methodology in the German National Cohort (NAKO) and to present initial descriptive results in a subsample of the cohort.In the NAKO, hand grip strength (GS) and CRF as physical fitness components were assessed at baseline using a hand dynamometer and a submaximal bicycle ergometer test, respectively. Maximum oxygen uptake (VO2max) was estimated as a result of the bicycle ergometer test. The results of a total of 99,068 GS measurements and 3094 CRF measurements are based on a data set at halftime of the NAKO baseline survey (age 20-73 years, 47% men).Males showed higher values of physical fitness compared to women (males: GS = 47.8 kg, VO2max = 36.4 ml·min-1 · kg-1; females: GS = 29.9 kg, VO2max = 32.3 ml · min-1 · kg-1). GS declined from the age of 50 onwards, whereas VO2max levels decreased continuously between the age groups of 20-29 and ≥60 years. GS and VO2max showed a linear positive association after adjustment for body weight (males ß = 0.21; females ß = 0.35).These results indicate that the physical fitness measured in the NAKO are comparable to other population-based studies. Future analyses in this study will focus on examining the independent relations of GS and CRF with risk of morbidity and mortality.

[Physical activity in the German National Cohort (NAKO): use of multiple assessment tools and initial results]. / Körperliche Aktivität in der NAKO Gesundheitsstudie: erste Ergebnisse des multimodalen Erhebungskonzepts.

BACKGROUND: Physical activity is a complex behavior that is difficult to measure validly and reliably in large, population-based studies. Data on physical activity are available for the initial 100,000 participants of the German National Cohort. OBJECTIVES: To describe the baseline physical activity assessment in the cohort and to present initial descriptive results. MATERIAL AND METHODS: Physical activity was assessed using a combination of tools, including two self-administered questionnaires, the Questionnaire on Annual Physical Activity Pattern (QUAP) and the Global Physical Activity Questionnaire (GPAQ); a computer-based 24­h physical activity recall (cpar24); and 7­day accelerometry (Actigraph GT3X/+; ActiGraph, Pensacola, FL, USA). RESULTS: The availability of data varied between assessment instruments (QUAP: n = 16,372; GPAQ: n = 90,900; cpar24: n = 23,989; accelerometry: n = 35,218). Analyses across measurement tools showed that on average, women spent 75 to 216 min/d, and men spent 73 to 224 min/d in moderate or higher intensity total physical activity. Persons aged 20-39 years spent 66 to 200 min/d, and persons aged 40-69 years spent 78 to 244 min/d in moderate or higher intensity total physical activity. CONCLUSIONS: Initial baseline analyses of physical activity in this cohort show the value of using a combination of questionnaires, 24­h recalls, and a movement sensor. The comprehensive data collection represents a valuable resource for future analyses and will improve our understanding of the association between physical activity and disease prevention.

Association Between Osteoarthritis and Social Isolation: Data From the EPOSA Study.

OBJECTIVE: To determine whether there is an association between osteoarthritis (OA) and incident social isolation using data from the European Project on OSteoArthritis (EPOSA) study. DESIGN: Prospective, observational study with 12 to 18 months of follow-up. SETTING: Community dwelling. PARTICIPANTS: Older people living in six European countries. MEASUREMENTS: Social isolation was assessed using the Lubben Social Network Scale and the Maastricht Social Participation Profile. Clinical OA of the hip, knee, and hand was assessed according to American College of Rheumatology criteria. Demographic characteristics, including age, sex, multijoint pain, and medical comorbidities, were assessed. RESULTS: Of the 1967 individuals with complete baseline and follow-up data, 382 (19%) were socially isolated and 1585 were nonsocially isolated at baseline; of these individuals, 222 (13.9%) experienced social isolation during follow-up. Using logistic regression analyses, after adjustment for age, sex, and country, four factors were significantly associated with incident social isolation: clinical OA, cognitive impairment, depression, and worse walking time. Compared to those without OA at any site or with only hand OA, clinical OA of the hip and/or knee, combined or not with hand OA, led to a 1.47 times increased risk of social isolation (95% confidence interval = 1.03-2.09). CONCLUSION: Clinical OA, present in one or two sites of the hip and knee, or in two or three sites of the hip, knee, and hand, increased the risk of social isolation, adjusting for cognitive impairment and depression and worse walking times. Clinicians should be aware that individuals with OA may be at greater risk of social isolation. J Am Geriatr Soc 68:87-95, 2019.

Everyday Walking Among Older Adults and the Neighborhood Built Environment: A Comparison Between Two Cities in North America.

A walkable neighborhood becomes particularly important for older adults for whom physical activity and active transportation are critical for healthy aging-in-place. For many older adults, regular walking takes place in the neighborhood and is the primary mode of mobility. This study took place in eight neighborhoods in Metro Portland (USA) and Metro Vancouver (Canada), examining older adults' walking behavior and neighborhood built environmental features. Older adults reported walking for recreation and transport in a cross-sectional telephone survey. Information on physical activity was combined with audits of 355 street segments using the Senior Walking Environmental Audit Tool-Revised (SWEAT-R). Multi-level regression models examined the relationship between built environmental characteristics and walking for transport or recreation. Older adults [N = 434, mean age: 71.6 (SD = 8.1)] walked more for transport in high-density neighborhoods and in Metro Vancouver compared to Metro Portland (M = 12.8 vs. M = 2.2 min/day; p < 0.001). No relationship was found between population density and walking for recreation. Older adults spent more time walking for transport if pedestrian crossing were present (p = 0.037) and if parks or outdoor fitness amenities were available (p = 0.022). The immediate neighborhood built environment supports walking for transport in older adults. Comparing two similar metropolitan areas highlighted that high population density is necessary, yet not a sufficient condition for walking in the neighborhood.

Quality of Life, Fatigue, and Sleep Problems in Pancreatic Cancer Patients­A Randomized Trial on the Effects of Exercise

BACKGROUND: Improving quality of life (QoL) is an important treatment goal in pancreatic cancer patients. Although the beneficial effects of exercise on QoL are well understood, few studies have investigated more aggressive cancers such as pancreatic cancer. METHODS: Within a randomized trial, we assessed the efficacy of 6-month resistance training on physical functioning (primary outcome) and further QoL-related outcomes. 65 pancreatic cancer patients were assigned to home-based training, supervised training, or a usual care control group. Analysis-of-covariance models on changes from baseline to 6 and 3 months were ap- plied. RESULTS: 47 patients completed the intervention period. After 6 months, no effects of resistance training were observed. However, after 3 months, explorative analyses showed significant between-group mean differences (MD) in favor for resistance training for physical functioning (pooled group: MD=11.0; p=0.016; effect size[ES]=0.31), as well as for global QoL (MD=12.1; p=0.016; effect size=0.56), and other outcomes, such as sleep problems and fatigue. Multiple imputation analyses yielded similar results. Home-based and supervised training performed similarly. CONCLUSION: This first randomized resistance training trial in pancreatic cancer patients indicated clinically relevant improve- ments in QoL after 3 but not after 6 months. Given the severity of pancreatic cancer, exercise recommendations may already commence at surgery.

Minimal clinically important decline in physical function over one year: EPOSA study.

BACKGROUND: The Australian/Canadian hand Osteoarthritis Index (AUSCAN) and the Western Ontario and McMaster Universities knee and hip Osteoarthritis Index (WOMAC) are the most commonly used clinical tools to manage and monitor osteoarthritis (OA). Few studies have as yet reported longitudinal changes in the AUSCAN index regarding the hand. While there are published data regarding WOMAC assessments of the hip and the knee, the two sites have always evaluated separately. The current study therefore sought to determine the minimal clinically important difference (MCID) in decline in the AUSCAN hand and WOMAC hip/knee physical function scores over 1 year using anchor-based and distribution-based methods. METHODS: The study analysed data collected by the European Project on Osteoarthritis, a prospective observational study investigating six adult cohorts with and without OA by evaluating changes in the AUSCAN and WOMAC physical function scores at baseline and 12-18 months later. Pain and stiffness scores, the performance-based grip strength and walking speed and health-related quality of life measures were used as the study's anchors. Receiver operating characteristic curves and distribution-based methods were used to estimate the MCID in the AUSCAN and WOMAC physical function scores; only the data of those participants who possessed paired (baseline and follow up-measures) AUSCAN and WOMAC scores were included in the analysis. RESULTS: Out of the 1866 participants who were evaluated, 1842 had paired AUSCAN scores and 1845 had paired WOMAC scores. The changes in the AUSCAN physical function score correlated significantly with those in the AUSCAN pain score (r = 0.31). Anchor- and distribution-based approaches converged identifying 4 as the MCID for decline in the AUSCAN hand physical function. Changes in the WOMAC hip/knee physical function score were significantly correlated with changes in both the WOMAC pain score (r = 0.47) and the WOMAC stiffness score (r = 0.35). The different approaches converged identifying two as the MCID for decline in the WOMAC hip/knee physical function. CONCLUSIONS: The most reliable MCID estimates of decline over 1 year in the AUSCAN hand and WOMAC hip/knee physical function scores were 4 and 2 points, respectively.

To rest or not to rest-Health care professionals' attitude toward recommending physical activity to their cancer patients.

OBJECTIVE: While in the past cancer patients were advised to rest, recent research revealed various beneficial effects of physical activity, including increased treatment tolerability during cancer treatment and prolonged survival, which has led to a paradigm shift in relevant guidelines. This study examined if this paradigm shift from rest to activity has been consolidated in health care professionals' (HCP') attitude. It was investigated if the two dimensions of attitude (rest and activity) are endorsed empirically within the theory of planned behavior (TPB). Differences between physicians and nurses were examined. METHODS: Five hundred forty seven physicians and 398 nurses treating breast, prostate, or colorectal cancer patients completed a cross-sectional questionnaire. To assess attitude toward physical activity during cancer treatment, we developed a 15-item scale, which included original statements of HCP. TPB variables were assessed. RESULTS: A factor analysis revealed the proposed distinction of attitude into two dimensions. The activity-paradigm was stronger represented in HCP' attitude compared with rest-paradigm (Mactivity-paradigm  = 4.1 versus Mrest-paradigm  = 2.7, p < 0.001). Additionally, the activity-paradigm had higher exploratory power in explaining intention to recommend physical activity in cancer patients. However, the rest-paradigm was able to explain intention to recommend physical activity over and above activity-paradigm (ΔR2  = 0.05). Nurses had higher scores on the rest-paradigm than physicians. CONCLUSIONS: The activity-paradigm has already been consolidated in HCP' minds. However, the rest-paradigm is still present in the daily routine of oncology physicians and nurses. Addressing concerns and insecurities related to supporting cancer patients in maintaining or building up a physically active lifestyle is a very important educational task.

Within-person pain variability and physical activity in older adults with osteoarthritis from six European countries.

BACKGROUND: This study examines the association of both pain severity and within-person pain variability with physical activity (PA) in older adults with osteoarthritis (OA). METHODS: Data from the European Project on OSteoArthritis were used. At baseline, clinical classification criteria of the American College of Rheumatology were used to diagnose OA in older adults (65-85 years). At baseline and 12-18 months follow-up, frequency and duration of participation in the activities walking, cycling, gardening, light and heavy household tasks, and sports activities were assessed with the Longitudinal Aging Study Amsterdam Physical Activity Questionnaire. Physical activity was calculated in kcal/day, based on frequency, duration, body weight and the metabolic equivalent of each activity performed. At baseline and 12-18 months follow-up, pain severity was assessed using the pain subscales of the Western Ontario and McMaster Universities OA Index and the Australian/Canadian Hand OA Index. Within-person pain variability was assessed using two-week pain calendars that were completed at baseline, 6 months follow-up and 12-18 months follow-up. RESULTS: Of all 669 participants, 70.0% were women. Sex-stratified multiple linear regression analyses showed that greater pain severity at baseline was cross-sectionally associated with less PA in women (Ratio = 0.95, 95% CI = 0.90-0.99), but not in men (Ratio = 0.99, 95% CI = 0.85-1.15). The longitudinal analyses showed a statistically significant inverse association between pain severity at baseline and PA at follow-up in women (Ratio = 0.94, 95% CI = 0.89-0.99), but not in men (Ratio = 1.00, 95% CI = 0.87-1.11). Greater pain variability over 12-18 months was associated with more PA at follow-up in men (Ratio = 1.18, 95% CI = 1.01-1.38), but not in women (Ratio = 0.94, 95% CI = 0.86-1.03). CONCLUSIONS: Greater pain severity and less pain variability are associated with less PA in older adults with OA. These associations are different for men and women. The observed sex differences in the various associations should be studied in more detail and need replication in future research.

Why Is Social Isolation Among Older Adults Associated with Depressive Symptoms? The Mediating Role of Out-of-Home Physical Activity.

BACKGROUND: Social networks are known to be a key factor associated with late-life depression. However, there is limited knowledge about the pathways linking social isolation to mental health. It has been proposed that health-related behaviors such as physical activity represent one pathway. This study examines the way out-of-home physical activity mediates between social isolation and depressive symptoms in older adults. METHODS: A subsample of 334 older adults from the ActiFE Ulm study, Germany, was randomly selected. Older adults (M = 72.6 years; 60.8% male) were interviewed at baseline and 3 years later. Depressive symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS). Social isolation was measured using the Lubben Social Network Scale (LSNS-6). Physical activity was measured by an accelerometer (activPAL) over 1 week. To identify out-of-home physical activity, a contemporary physical activity diary classified out-of-home physical activity. RESULTS: A cross-lagged structural equation model supported an indirect effect (ß = .014, 95% CI .002 to .039) which means that being socially isolated was associated with lower levels of out-of-home physical activity, and this predicted more depressive symptoms after 3 years. However, no direct relationship was observed between social isolation from friends and neighbors at the baseline and depressive symptoms 3 years later. CONCLUSIONS: Utilizing a longitudinal study design and accounting for reverse causality, this study extends prior work linking social isolation to depression by showing that a variety of neighbor and friendship ties are linked to fewer depressive symptoms by providing occasions for out-of-home physical activity.

Cognitive function and the agreement between self-reported and accelerometer-accessed physical activity.

BACKGROUND: Numerous studies have reported weak or moderate correlations between self-reported and accelerometer-assessed physical activity. One explanation is that self-reported physical activity might be biased by demographic, cognitive or other factors. Cognitive function is one factor that could be associated with either overreporting or underreporting of daily physical activity. Difficulties in remembering past physical activities might result in recall bias. Thus, the current study examines whether the cognitive function is associated with differences between self-reported and accelerometer-assessed physical activity. METHODS: Cross-sectional data from the population-based Activity and Function in the Elderly in Ulm study (ActiFE) were used. A total of 1172 community-dwelling older adults (aged 65-90 years) wore a uniaxial accelerometer (activPAL unit) for a week. Additionally, self-reported physical activity was assessed using the LASA Physical Activity Questionnaire (LAPAQ). Cognitive function was measured with four items (immediate memory, delayed memory, recognition memory, and semantic fluency) from the Consortium to Establish a Registry for Alzheimer's Disease Total Score (CERAD-TS). RESULTS: Mean differences of self-reported and accelerometer-assessed physical activity (MPA) were associated with cognitive function in men (rs = -.12, p = .002) but not in women. Sex-stratified multiple linear regression analyses showed that MPA declined with high cognitive function in men (ß = -.13; p = .015). CONCLUSION: Results suggest that self-reported physical activity should be interpreted with caution in older populations, as cognitive function was one factor that explained the differences between objective and subjective physical activity measurements.

Expression and Activity of the Small RhoGTPase Cdc42 in Blood Cells of Older Adults Are Associated With Age and Cardiovascular Disease.

The small RhoGTPase Cdc42 is mechanistically linked to aging of multiple tissues and to rejuvenation of hematopoietic stem cells in mice. However, data validating Cdc42 activity and expression as biomarker for aging in humans are still missing. Here, we hypothesized that Cdc42 might serve as a novel biomarker of aging in older adults and therefore we determined Cdc42 activity and expression levels in peripheral blood cells from a cohort of 196 donors. We investigated the association of these parameters with both chronological and biological aging. We also tested in this cohort of older adults a recently published algorithm determining chronological age based on DNA methylation profiles. A positive correlation with chronological age was found for both the level of Cdc42 mRNA and the level of active Cdc42 protein (the GTP bound form). Notably, the level of Cdc42 mRNA as well as total protein showed a specific strong association to cardiovascular disease and Cdc42 mRNA levels also to a history of myocardial infarction. In summary, these data validate Cdc42 as a blood biomarker of both chronological aging as well as aging-associated diseases like cardiovascular disease and myocardial infarction.

Relationship between Social Isolation and Indoor and Outdoor Physical Activity in Community-Dwelling Older Adults in Germany: Findings from the ActiFE Study

Objectives: Social relationships have a powerful effect on physical activity. However, it is unclear how physical activity patterns are associated with perceived social isolation. Methods: A cohort study was performed on 1,162 community-dwelling older adults. In cross-sectional analyses, social isolation was screened using the Lubben Social Network Scale (LSNS-6). Physical activity was measured by an accelerometer (activPAL). Participants kept a contemporary physical activity diary to report outdoor physical activity timeframes. Results: Low levels of physical activity were associated with perceived social isolation. Low indoor physical activity was associated with being socially isolated from family and low outdoor physical activity was associated with being socially isolated from friends and neighbors (-4.5 minutes; p=.012). Discussion: These findings suggest the need for a more nuanced assessment of non-kin networks and a differentiated analysis of the locations in which physical activity is done in order to understand how social isolation affects everyday physical activity.

The Influence of Weather Conditions on Outdoor Physical Activity Among Older People With and Without Osteoarthritis in 6 European Countries.

BACKGROUND: Older adults with osteoarthritis (OA) often report that their disease symptoms are exacerbated by weather conditions. This study examines the association between outdoor physical activity (PA) and weather conditions in older adults from 6 European countries and assesses whether outdoor PA and weather conditions are more strongly associated in older persons with OA than in those without the condition. METHODS: The American College of Rheumatology classification criteria were used to diagnose OA. Outdoor PA was assessed using the LASA Physical Activity Questionnaire. Data on weather parameters were obtained from weather stations. RESULTS: Of the 2439 participants (65-85 years), 29.6% had OA in knee, hand and/or hip. Participants with OA spent fewer minutes in PA than participants without OA (Median = 42.9, IQR = 20.0 to 83.1 versus Median = 51.4, IQR = 23.6 to 98.6; P < .01). In the full sample, temperature (B = 1.52; P < .001) and relative humidity (B = -0.77; P < .001) were associated with PA. Temperature was more strongly associated with PA in participants without OA (B = 1.98; P < .001) than in those with the condition (B = 0.48; P = .47). CONCLUSIONS: Weather conditions are associated with outdoor PA in older adults in the general population. Outdoor PA and weather conditions were more strongly associated in older adults without OA than in their counterparts with OA.

Physical Activity Patterns Among Older Adults With and Without Knee Osteoarthritis in Six European Countries.

OBJECTIVE: To investigate patterns of physical activity in older adults with knee osteoarthritis (OA) compared to older adults without knee OA across 6 European countries. We expect country-specific differences in the physical activity levels between persons with knee OA compared to persons without knee OA. A varying degree of physical activity levels across countries would express a facilitating or impeding influence of the social, environmental, and other contextual factors on a physically active lifestyle. METHODS: Baseline cross-sectional data from the European Project on Osteoarthritis were analyzed. In total, 2,551 participants from 6 European countries (Germany, Italy, The Netherlands, Spain, Sweden, and the UK) were included. RESULTS: Participants with knee OA were less likely to follow physical activity recommendations and had poorer overall physical activity profiles than those without knee OA (mean 62.9 versus 81.5 minutes/day, respectively; P = 0.015). The magnitude of this difference varied across countries. Detailed analysis showed that low physical activity levels in persons with knee OA could be attributed to less everyday walking time (odds ratio 1.31, 95% confidence interval 1.07-1.62). CONCLUSION: This study highlighted the fact that having knee OA is associated with a varying degree of physical activity patterns in different countries. This national variation implies that low levels of physical activity among persons with knee OA cannot be explained exclusively by individual or disease-specific factors, but that social, environmental, and other contextual factors should also be taken into account.