Validation of accelerometer wear and nonwear time classification algorithm

Examining the Influence of a New Light Rail Line on the Health of a Demographically Diverse and Understudied Population within the Washington, D.C. Metropolitan Area: A Protocol for a Natural Experiment Study

Approximately two-thirds of adults and youth in Prince George's County, Maryland, a suburb of Washington, D.C. are overweight or obese and less than half are achieving daily physical activity recommendations. Active transportation (AT), such as walking, biking or using public transportation (PT), is a strategic pathway to improving physical activity levels and thus reducing excess weight. Utilizing an expansion of the Washington, D.C. area transportation system with a new light rail line, the Purple Line Outcomes on Transportation (PLOT) Study will exam pre- and post-Purple Line PT use, AT behaviors and attitudes and physical activity among Prince George's County adults and youth. The PLOT Study will take advantage of this natural experiment in an area enduring significant racial/ethnic and gender-based overweight or obesity and physical inactivity disparities. While similar natural experiments on AT have been conducted in other U.S. cities, those studies lacked diverse and representative samples. To effectively evaluate these physical activity outcomes among this population, efforts will be used to recruit African American and Latino populations, the first and second most common racial/ethnic groups in Prince George's County. Finally, the PLOT Study will also examine how contextual effects (e.g., neighborhood built environment) impact PT, AT and physical activity.

Patterns of Fitbit Use and Activity Levels Throughout a Physical Activity Intervention: Exploratory Analysis from a Randomized Controlled Trial

BACKGROUND

There has been a rapid increase in the use of technology-based activity trackers to promote behavior change. However, little is known about how individuals use these trackers on a day-to-day basis or how tracker use relates to increasing physical activity.

OBJECTIVE

The aims were to use minute level data collected from a Fitbit tracker throughout a physical activity intervention to examine patterns of Fitbit use and activity and their relationships with success in the intervention based on ActiGraph-measured moderate to vigorous physical activity (MVPA).

METHODS

Participants included 42 female breast cancer survivors randomized to the physical activity intervention arm of a 12-week randomized controlled trial. The Fitbit One was worn daily throughout the 12-week intervention. ActiGraph GT3X+ accelerometer was worn for 7 days at baseline (prerandomization) and end of intervention (week 12). Self-reported frequency of looking at activity data on the Fitbit tracker and app or website was collected at week 12.

RESULTS

Adherence to wearing the Fitbit was high and stable, with a mean of 88.13% of valid days over 12 weeks (SD 14.49%). Greater adherence to wearing the Fitbit was associated with greater increases in ActiGraph-measured MVPA (b_interaction=0.35, P<.001). Participants averaged 182.6 minutes/week (SD 143.9) of MVPA on the Fitbit, with significant variation in MVPA over the 12 weeks (F=1.91, P=.04). The majority (68%, 27/40) of participants reported looking at their tracker or looking at the Fitbit app or website once a day or more. Changes in Actigraph-measured MVPA were associated with frequency of looking at one's data on the tracker (b=-1.36, P=.07) but not significantly associated with frequency of looking at one's data on the app or website (P=.36).

CONCLUSIONS

This is one of the first studies to explore the relationship between use of a commercially available activity tracker and success in a physical activity intervention. A deeper understanding of how individuals engage with technology-based trackers may enable us to more effectively use these types of trackers to promote behavior change.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02332876; https://clinicaltrials.gov/ct2/show/NCT02332876?term=NCT02332876 &rank=1 (Archived by WebCite at http://www.webcitation.org/6wplEeg8i).

Cross-sectional associations between maternal self-efficacy and dietary intake and physical activity in four-year-old children of first-time Swedish mothers

BACKGROUND

Healthy dietary and physical activity behaviours are established early in life where children learn by observing their parents. Therefore, parents can act as role models and influence their children toward a healthier lifestyle. Besides a strong association between parental and child health behaviours, parents also influence their children's health behaviours through socio-cognitive processes, where perceived self-efficacy is the central component. The objective was to examine if parental self-efficacy among Swedish mothers was associated with their four-year-old children's dietary and physical activity behaviours.

METHODS

This cross-sectional study was based on information from control participants that took part in the Swedish primary prevention trial of childhood obesity (PRIMROSE) (n = 420 mother-child pairs). Linear regression models were used to examine the associations between parental self-efficacy (Parental Self-Efficacy for Promoting Healthy Physical Activity and Dietary Behaviours in Children Scale) and children's dietary intake (parent reported) and levels of physical activity (accelerometer) with adjustments for potential confounders.

RESULTS

Mothers' efficacy beliefs in promoting healthy dietary or physical activity behaviours in their children were associated with a slightly higher consumption of fruit and vegetables among their children (β: 0.03 [95%CI: 0.01; 0.04] P < 0.001) and slightly higher levels of moderate-to-vigorous activity (β: 0.43 [95%CI: 0.05; 0.81] P = 0.03). Mothers' belief in their ability to limit unhealthy dietary and physical activity behaviours was inversely associated with children's intake of unhealthy snacks (β: -0.06 [95%CI: -0.10; -0.02] P < 0.01).

CONCLUSION

Our cross-sectional study suggests weak positive correlations between maternal self-efficacy and healthy dietary and physical activity behaviours, and weak inverse associations between maternal self-efficacy and unhealthy dietary and physical activity behaviours among their children.

The association between bouts of moderate to vigorous physical activity and patterns of sedentary behavior with frailty

OBJECTIVES

To determine if bouts of moderate-vigorous physical activity (MVPA) and patterns of sedentary behavior are associated with frailty.

METHOD

Accelerometry from community-dwelling adults ≥50 years old (n = 2317) enrolled in the 2003-04 and 2005-06 National Health and Nutrition Examination Survey were used. Bouted (≥10 min) and sporadic (<10 min) durations of MVPA were analyzed based on meeting 0%, 1-49%, 50-99%, and ≥100% of physical activity guidelines (150 min/week of MVPA). Prolonged sedentary behavior were bouts lasting ≥30 min. Breaks from sedentary behavior were defined as any ≥1 min interruption in sedentary behavior. Average intensity (counts/min) and duration (minutes) during breaks were also analyzed. Frailty was measured with a 46-item frailty index.

RESULTS

Multivariable linear regression models adjusting for age, sex, education, ethnicity, income, marital status, smoking, alcohol consumption, body mass index, total sedentary time and accelerometer wear time indicated that meeting any percentage of the activity guidelines with bouted and sporadic MVPA was associated with reduced frailty. This relationship peaked at meeting 50-99% of guidelines and was associated with a 1.5 and 2.0 point reduction in the frailty index for bouted and sporadic MVPA, respectively. Two additional prolonged sedentary behavior bouts/day were associated with an additional frailty index deficit while every additional 100 cpm in average break intensity and every 2 min in average break duration were associated with one less deficit. Total sedentary breaks were not associated with frailty.

CONCLUSION

These population-level data give justification for determining if interventions which target short bouts of MVPA and interrupting prolonged, uninterrupted time spent in sedentary behaviors can treat or prevent frailty worsening.

Effects of a Long-Term Physical Activity Program on Activity Patterns in Older Adults

PURPOSE

To examine the effect of a long-term structured physical activity (PA) intervention on accelerometer-derived metrics of activity pattern changes in mobility-impaired older adults.

METHODS

Participants were randomized to either a PA or health education (HE) program. The PA intervention included a walking regimen with strength, flexibility, and balance training. The HE program featured health-related discussions and a brief upper body stretching routine. Participants (n = 1341) wore a hip-worn accelerometer for ≥10 h·d for ≥3 d at baseline and again at 6, 12, and 24 months postrandomization. Total PA (TPA)-defined as movements registering 100+ counts per minute-was segmented into the following intensities: low-light PA (LLPA; 100-759 counts per minute), high light PA (HLPA; 760-1040 counts per minute), low moderate PA (LMPA; 1041-2019 counts per minute), and high moderate and greater PA (HMPA; 2020+ counts per minute). Patterns of activity were characterized as bouts (defined as the consecutive minutes within an intensity).

RESULTS

Across groups, TPA decreased an average of 74 min·wk annually. The PA intervention attenuated this effect (PA = -68 vs HE: -112 min·wk, P = 0.002). This attenuation shifted TPA composition by increasing time in LLPA (10+ bouts increased 6 min·wk), HLPA (1+, 2+, 5+, and 10+ bouts increased 6, 3, 2, and 1 min·wk, respectively), LMPA (1+, 2+, 5+, and 10+ bouts increased: 19, 17,16, and 8 min·wk, respectively), and HMPA (1+, 2+, 5+, and 10+ bouts increased 23, 21, 17, and 14 min·wk, respectively).

CONCLUSIONS

The PA intervention increased PA by shifting the composition of activity toward higher-intensity activity in longer-duration bouts. However, a long-term structured PA intervention did not completely eliminate overall declines in total daily activity experienced by mobility-impaired older adults.

Centre- versus home-based exercise among people with mci and mild dementia: study protocol for a randomized parallel-group trial

Background

Worldwide, almost 50million people lived with dementia in 2016. A cure or disease modifying pharmaceutical treatment for dementia remains elusive so alternative therapies are of critical importance. Mounting evidence supports exercise in the prevention and therapy of dementia. However, the cognitive, physical, and psychological challenges common to dementia along with a poor understanding and accommodation of dementia in the community are major barriers to exercise. Consequently, effective delivery options need to be identified. The primary objective of this study is to compare the effectiveness of center-based (CB) exercise versus home-based (HB) exercise for achievement of physical activity guidelines among people with MCI or mild dementia.

Methods

This is a randomized parallel-group trial comparing the effects of CB and HB exercise adherence among community-dwelling adults ≥50 years with a clinical diagnosis of MCI or mild dementia. Participants will be randomized to either CB or HB exercise. The CB group will meet weekly for small group exercise and will be prescribed additional exercise to be completed independently. Participants in the HB group will be given a physical activity prescription to be completed independently in the community. Participants in HB will also be contacted by phone monthly to adjust exercise prescriptions. The primary outcome will be achievement of exercise guidelines (150 min/wk. of moderate activity) assessed using an activity monitor. Secondary objectives will evaluate cost-effectiveness and the influence of individual and environmental factors on the primary outcome. Tertiary outcomes include physical function, cognition, mood, and quality of life.

Discussion

There is scant research to indicate the most effective way to deliver exercise to people with MCI and mild dementia, which is needed specifically because these groups face significant barriers to exercise. To capitalize on the benefits of exercise, feasible exercise delivery options need to be identified. The results of this study will directly complement ongoing clinical trials and will be essential to implementing exercise recommendations specific to the prevention and therapy of dementia in a feasible and cost-effective manner when they emerge.

Trial registration.

Clinicatrials.gov; Identifier: NCT02774720 (version updated December 12, 2016).

Serum adipokine levels and associations with patient-reported fatigue in systemic lupus erythematosus

Physical activity ameliorates fatigue in systemic lupus erythematosus (SLE) patients by an unknown mechanism. Adipokines, which are influenced by adiposity and physical activity, may be associated with patient-reported fatigue. We describe cross-sectional associations between adipokines and fatigue, physical activity, and SLE disease activity. We measured adipokines, self-reported fatigue, and objective physical activity in 129 SLE patients. Fatigue was assessed with the Fatigue Severity Scale (FSS) and Patient Reported Outcomes Measurement Information System^® (PROMIS^®) Fatigue score. Disease activity was measured with the Safety of Estrogens in Systemic Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index (SELENA-SLEDAI). Participants wore an accelerometer for 7 days to measure physical activity. Leptin, adiponectin, and resistin were measured in stored serum with a Luminex bead-based assay. Multivariable regression models assessed relationships between fatigue and adipokines, and Spearman correlation coefficients summarized associations between adipokines, physical activity, and SELENA-SLEDAI. Median adipokine levels were: leptin 30.5 ng/ml (Interquartile Range 14.0, 56.6), adiponectin 11.6 μg/ml (7.2, 16.8) and resistin 1.4 ng/ml (1.0, 2.2). Associations between adipokines and FSS or PROMIS fatigue were not significant. Body mass index (BMI) ≥ 30 kg/m² was associated with FSS and PROMIS fatigue in regression analyses (p < 0.05). Weak correlations between leptin, adiponectin, leptin/adiponectin (L/A) ratio, and physical activity and between adiponectin and SELENA-SLEDAI score were not significant after adjusting for BMI. Adipokines were not associated with fatigue in SLE. Adipokines were correlated with physical activity (leptin, adiponectin, L/A ratio) and SLE disease activity (adiponectin), but most of these associations were explained by BMI.

The effects of Ramadan fasting on activity and energy expenditure

Background

Fasting during the month of Ramadan entails abstinence from eating and drinking between dawn and sunset and a major shift in meal times and patterns with associated changes in several hormones and circadian rhythms; whether there are accompanying changes in energy metabolism is unclear.

Objective

We have investigated the impact of Ramadan fasting on resting metabolic rate (RMR), activity, and total energy expenditure (TEE).

Design

Healthy nonobese volunteers (n = 29; 16 women) fasting during Ramadan were recruited. RMR was measured with the use of indirect calorimetry. In subgroups of participants, activity (n = 11; 5 women) and TEE (n = 10; 5 women) in free-living conditions were measured with the use of accelerometers and the doubly labeled water technique, respectively. Body composition was measured with the use of bioelectrical impedance. Measurements were repeated after a wash-out period of between 1 and 2 mo after Ramadan. Nonparametric tests were used for comparative statistics.

Results

Ramadan fasting did not result in any change in RMR (mean ± SD: 1365.7 ± 230.2 compared with 1362.9 ± 273.6 kcal/d for Ramadan and post-Ramadan respectively, P = 0.713, n = 29). However, controlling for the effects of age, sex, and body weight, RMR was higher in the first week of Ramadan than in subsequent weeks. During Ramadan, the total number of steps walked were significantly lower (n = 11, P = 0.001), while overall sleeping time was reduced and different sleeping patterns were seen. TEE did not differ significantly between Ramadan and post-Ramadan (mean ± SD: 2224.1 ± 433.7 compared with 2121.0 ± 718.5 kcal/d for Ramadan and post-Ramadan, P = 0.7695, n = 10).

Conclusions

Ramadan fasting is associated with reduced activity and sleeping time, but no significant change in RMR or TEE. Reported weight changes with Ramadan in other studies are more likely to be due to differences in food intake. This trial is registered at clinicaltrials.gov as NCT02696421.

Association of physical activity with lung function in lung-healthy German adults: results from the KORA FF4 study

BACKGROUND

In lung disease, physical activity (PA) yields beneficial health effects, but its association with the function of healthy lungs has rarely been studied. We investigated the association of accelerometer-based PA with spirometric indices, maximal inspiratory mouth pressure (PI_max) and lung diffusion capacity in lung-healthy adults.

METHODS

In total, 341 apparently lung-healthy participants from the population-based KORA (Cooperative Health Research in the Region of Augsburg) FF4 cohort study (45% male, aged 48-68 years, 47% never smokers) completed lung function testing and wore ActiGraph accelerometers over a one week period at the hip. In adjusted regression analyses, moderate to vigorous PA (MVPA) was characterized as: sex-specific activity quartiles, achieving ≥ 10 consecutive minutes (yes vs. no), and meeting the WHO PA recommendations (yes vs. no).

RESULTS

Positive associations of MVPA-quartiles with forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC), and corresponding Global Lung Function Initiative z-scores were found. Subjects in the most active quartile (> 47 or > 50 min/day for females and males, respectively) had 142 ml [95% CI: 23, 260] higher FEV₁ and 155 ml [95% CI: 10, 301] higher FVC than those in the least active quartile (< 17 or < 21 min/day for females and males, respectively); however these associations were stronger among ex-/current smokers. Achieving at least once 10 consecutive minutes of MVPA was only associated with higher PI_max [β-estimate: 0.57 kPa; 95% CI: 0.04, 1.10], remaining significant among never smokers. No associations were found with diffusion capacity or for reaching the WHO-recommended 150 min of MVPA/week in 10-min bouts.

CONCLUSIONS

Although the effects were small, active subjects showed higher spirometric results. The observed associations were more pronounced among ever smokers suggesting a higher benefit of PA for subjects being at a higher risk for chronic lung diseases.

Four years' follow-up changes of physical activity and sedentary time in women undergoing roux-en-Y gastric bypass surgery and appurtenant children

BACKGROUND

Objectively measured levels of physical activity (PA) in patients undergoing Roux-en-Y Gastric Bypass (RYGB) surgery remain essentially unchanged from before to one year after surgery. Effects from RYGB on objectively measured levels of PA among women undergoing RYGB and appurtenant children beyond one year post-surgery are unknown. The aim of the present study was to objectively assess longitudinal changes in PA and sedentary time (ST), among women undergoing RYGB and appurtenant children, from three months before to nine and 48 months after maternal surgery.

METHODS

Thirty women undergoing RYGB and 40 children provided anthropometric measures during home visits and valid accelerometer assessed (Actigraph GT3X+) PA data, three months before and nine and 48 months after maternal RYGB surgery.

RESULTS

Women undergoing RYGB decreased time spent in moderate to vigorous PA (MVPA) with 2.0 min/day (p = 0.65) and increased ST with 14.4 min/day (p = 0.35), whereas their children decreased time spent in MVPA with 13.2 min/day (p = 0.04) and increased ST with 110.5 min/day (p < 0.001), from three months before to 48 months after maternal surgery. Twenty, 27 and 33% of women, and 60, 68 and 35% of children reached current PA guidelines three months before and nine and 48 months after maternal RYGB, respectively.

CONCLUSIONS

Objectively measured PA in women remains unchanged, while appurtenant children decrease time spent in MVPA and increase ST, from three months before through nine and 48 months after maternal RYGB. The majority of both women undergoing RYGB and children are insufficiently active 48 months after maternal RYGB.

Associations Between Objectively Measured Physical Activity and Executive Functioning in Young Adults

Associations between daily physical activity (PA) and executive functioning have rarely been investigated among young adults. This study examined these associations among 162 university students (74 females and 88 males; mean age = 19.0, SD = 1.1 years). We measured PA objectively, using hip-mounted accelerometers, and assessed executive functioning in a task-switching paradigm. Anthropometrics measurements were gathered using standardized procedures. Through linear regression modeling, we found moderate-to-vigorous physical activity (β = −0.19, 95% CI = [−0.35, −0.03], p = .02) and light physical activity (β = −0.17, 95% CI = [−0.34, −0.01], p = .04) to be associated with smaller global reaction time switch costs. Total PA was not associated with task-switching performance, and there were no statistically significant associations between PA indicators and local switch costs. As both moderate-to-vigorous and light physical activities were associated with better executive function in young adults, there can be important cognitive benefits to remaining physically active.

Bariatric Surgery Patients and Their Families: Health, Physical Activity, and Social Support

BACKGROUND

This study evaluated the social environment of bariatric surgery patients in the preoperative period.

METHODS

Forty bariatric surgery patients (mean = 46.2 ± 11.2 years), 35 adult cohabitating family members (mean = 45.2 ± 12.7 years), and 15 cohabitating children (mean = 11.5 ± 3.6 years) were recruited from a large rural medical center. Adult participants (patients and family members) completed height, weight, body composition, blood draws, and physical activity assessments (accelerometry), as well as eating behavior and social support inventories before the patient underwent bariatric surgery. Child participants completed demographic, height, and weight assessment only.

RESULTS

Over 90 % of adult family members were overweight or obese (body mass index (BMI) ≥ 25 kg/m², as were 50 % of children (BMI percentile ≥ 85 %). More than one third (37.1 %) of family members met the criteria for moderate to severe insulin resistance. Physical activity measured by accelerometry was moderately correlated between the patient and adult family members (r = 0.46, p = 0.023). Bariatric surgery patients reported high levels of social support from their family members on multiple social support measures.

CONCLUSIONS

Many family members of bariatric surgery patients also lived with obesity and related comorbidities, and demonstrate high sedentary behavior. However, patients reported high levels of support from family members, including support in following a healthy diet and engaging in physical activity. Engaging families in behavior change may help bariatric surgery patients and their families to become healthier.

Accelerometer-determined peak cadence and weight status in children from São Caetano do Sul, Brazil

The purpose of this study was to determine the relationship between peak cadence indicators and body mass index (BMI) and body fat percentage (BF%)-defined weight status in children. The sample comprised 485 Brazilian children. Minute-by-minute step data from accelerometry were rank ordered for each day to identify the peak 1-minute, 30-minute and 60-minute cadence values. Data were described by BMI-defined and bioelectrical impedance-determined BF% weight status. BMI-defined normal weight children had higher peak 1-minute (115.5 versus 110.6 and 106.6 steps/min), 30-minute (81.0 versus 77.5 and 74.0 steps/min) and 60-minute cadence (67.1 versus 63.4 and 60.7 steps/min) than overweight and obese children (p<.0001), respectively. Defined using %BF, normal weight children had higher peak 1-minute (114.5 versus 106.1 steps/min), 30-minute (80.4 versus 73.1 steps/min) and 60-minute cadence (66.5 versus 59.9 steps/min) than obese children (p<.0001). Similar relationships were observed in boys; however, only peak 1- minute cadence differed significantly across BMI and %BF-defined weight status categories in girls. Peak cadence indicators were negatively associated with BMI and BF% in these schoolchildren and significantly higher among normal weight compared to overweight or obese children.

Validation of the IPAQ Against Different Accelerometer Cut-Points in Older Cancer Survivors and Adults at Risk of Cancer

The present study investigated the convergent validity of an interview-administered IPAQ long version (IPAQ-L) in an older population by comparison with objective accelerometry movement data. Data from 52 participants (mean age 67.9 years, 62% male) were included in the analysis. Treadmill derived (TM-ACC: 1,952-5,724 cpm) and free-living physical activity (PA) derived (FL-ACC: 760-5,724 cpm) accelerometer cut-points were used as criterion. IPAQ-L measures (total PA, leisure-time, walking-time, sedentary time) were significantly correlated with accelerometry (P ≤ .05). Differences in sex were observed. Bland-Altman Limits of Agreement analysis showed that the IPAQ-L overestimated PA in relation to accelerometry. Our results show that an interview-administered IPAQ-L shows low to moderate convergent validity with objective PA measures in this population but there may be differences between males and females which should be further investigated.

Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study

BACKGROUND

Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study.

METHODS AND RESULTS

Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates.

CONCLUSIONS

Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500.

Objectively Measured Physical Activity, Sedentary Behavior, and Genetic Predisposition to Obesity in U.S. Hispanics/Latinos: Results From the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Studies using self-reported data suggest a gene-physical activity interaction on obesity, yet the influence of sedentary behavior, distinct from a lack of physical activity, on genetic associations with obesity remains unclear. We analyzed interactions of accelerometer-measured moderate to vigorous physical activity (MVPA) and time spent sedentary with genetic variants on obesity among 9,645 U.S. Hispanics/Latinos. An overall genetic risk score (GRS), a central nervous system (CNS)-related GRS, and a non-CNS-related GRS were calculated based on 97 BMI-associated single nucleotide polymorphisms (SNPs). Genetic association with BMI was stronger in individuals with lower MVPA (first tertile) versus higher MVPA (third tertile) (β = 0.78 kg/m2 [SE, 0.10 kg/m2] vs. 0.39 kg/m2 [0.09 kg/m2] per SD increment of GRS; Pinteraction = 0.005), and in those with more time spent sedentary (third tertile) versus less time spent sedentary (first tertile) (β = 0.73 kg/m2 [SE, 0.10 kg/m2] vs. 0.44 kg/m2 [0.09 kg/m2]; Pinteraction = 0.006). Similar significant interaction patterns were observed for obesity risk, body fat mass, fat percentage, fat mass index, and waist circumference, but not for fat-free mass. The CNS-related GRS, but not the non-CNS-related GRS, showed significant interactions with MVPA and sedentary behavior, with effects on BMI and other adiposity traits. Our data suggest that both increasing physical activity and reducing sedentary behavior may attenuate genetic associations with obesity, although the independence of these interaction effects needs to be investigated further.

Acculturation Influences Postpartum Eating, Activity, and Weight Retention in Low-Income Hispanic Women

BACKGROUND

Low-income Hispanic women experience elevated rates of high postpartum weight retention (PPWR), which is an independent risk factor for lifetime obesity. Sociocultural factors might play an important role among Hispanic women; however, very few studies have examined this association.

OBJECTIVE

The purpose of our study was to examine the associations between acculturation and maternal diet, physical activity, and PPWR.

DESIGN

This is a cross-sectional study of baseline data from 282 Hispanic women participating in the FitMoms/Mamás Activas study, a randomized controlled trial examining the impact of primarily an internet-based weight control program, in reducing PPWR among low-income women. We performed multivariable linear regression to examine the association of acculturation with diet quality, physical activity, and PPWR at study entry.

RESULTS

A total of 213 (76%) women had acculturation scores reflecting Mexican orientation or bicultural orientation, whereas 69 (24%) had scores that represented assimilation to Anglo culture. Women who were more acculturated had lower intakes of fruits and vegetables, lower HEI scores, and lower physical activity levels than women who were less acculturated (p < 0.05). We found an association between acculturation and PPWR in that for every 1-unit increase in acculturation score, PPWR increased, on average, by 0.80 kg.

CONCLUSION

Higher acculturation was associated with poorer diet and physical activity behaviors and greater PPWR.

Objectively Assessed Physical Activity and its Association with Balance, Physical Function and Dyskinesia in Parkinson's Disease

BACKGROUND

The desirable effects of physical activity in individuals with Parkinson's disease are well-known, although according to results from previous studies factors associated with objectively assessed physical activity are not fully investigated.

OBJECTIVE

To investigate demographic, disease-related and mobility-related factors that associate with objectively measured physical activity, in a sample of older adults with mild to moderate Parkinson's disease.

METHODS

Demographic, disease-related and mobility-related factors were gathered by interview from a total of 91 older adults with Parkinson's disease, followed by an evaluation of balance control using the Mini-BESTest. After initial testing, participants wore a tri-axial accelerometer during a week of free-living. Correlation analysis and multiple linear regression was used to investigate factors associated with total PA, represented by total activity counts, and time in brisk walking.

RESULTS

Motor impairment, physical function, body mass index and dyskinesia contributed to the variance of total physical activity, explaining 34 % of the variance, while physical function and balance control were significant factors associated with brisk walking, explaining 22 %.

CONCLUSIONS

This study identified factors that have not been shown to associate with objectively measured physical activity previously, such as dyskinesia, balance control and self-rated physical function. The findings also demonstrated that associated factors differ, depending on the activity behavior being investigated. However, other factors than those included in this study may also be of importance.

Interpersonal Processes of Couples' Daily Support for Goal Pursuit: The Example of Physical Activity

Little is known about how couples' social support facilitates the pursuit of important goals in daily life. Using an interpersonal perspective, we examined the effects of support provision and receipt on same-day physical activity, and studied the role of partners' joint engagement in activities. One hundred nineteen heterosexual couples reported on target persons' received and partners' provided support across 28 diary days, yielding 2,854 valid days. A dyadic report on couples' joint engagement was obtained from a subset of 88 couples. Target persons' daily activity was objectively assessed via accelerometers. On days with high versus low levels of provided support, target persons' activity was 25 min higher. Support receipt mediated 20% of this effect. Joint engagement accounted for around half of the effects of provided and received support. Support provision is uniquely linked to goal implementation in everyday life. Joint engagement in activities may be one explanation for how support is facilitated.

Reliability and validity of the Youth Leisure-time Sedentary Behavior Questionnaire (YLSBQ)

OBJECTIVES

To develop a questionnaire able to assess time spent by youth in a wide range of leisure-time sedentary behaviors (SB) and evaluate its test-retest reliability and criterion validity.

DESIGN

Cross-sectional observational.

METHODS

The reliability sample included 194 youth, aged 10-18 years, who completed the questionnaire twice, separated by one-week interval. The validity study comprised 1207 participants aged 8-18 years. Participants wore an accelerometer for 7 consecutive days. The questionnaire was designed to assess the amount of time spent in twelve different SB during weekdays and weekends, separately. In order to avoid usual phenomenon of time over reporting, values were adjusted to real available leisure-time (LT) for each participant. Reliability was assessed by using Intraclass Correlation Coefficients (ICC) and weighted (quadratic) kappa (k), and validity was assessed by using Pearson correlation and Bland-Altman plots.

RESULTS

The reliability of questionnaire showed a moderate-to-substantial agreement for the most (91%) of items (k=0.43-0.74; ICC=0.41-0.79) with three items (4%) reaching an almost perfect agreement (ICC=0.82-0.83). Only 'sitting and talking' evidenced fair-to-moderate reliability (k=0.27-0.39; ICC=0.34-0.46). The relationship between average sedentary time assessed by the questionnaire and accelerometry was moderate (r=0.36; p<0.001). Systematic biases were not found between questionnaire and accelerometer sedentary time for average day (r=0.05; p=0.11) but Bland-Altman plots suggest moderate discrepancies between both methods of SB measurement (mean=19.86; limits of agreement=-280.04 to 319.76).

CONCLUSIONS

The questionnaire showed moderate to good test-retest reliability and a moderate level of validity for assessing SB in youth, similar or slightly better to previously published in this population.

Effect of Physical Activity on Cognitive Development: Protocol for a 15-Year Longitudinal Follow-Up Study

The aim of the study is to investigate the relationship between physical activity as assessed by accelerometers and cognitive development across the human age ranges (from children and adolescents to adults). Additionally, this study seeks to explore whether physical activity contributes to cognitive development via modification of plasma insulin-like growth factor 1 (IGF-1) and brain-derived neurotrophic factor (BDNF). In the study, 500 preschool children (3.5–5.5 years old) are taking part in 6 triennial assessment waves over the span of 15 years. At each wave, participant measures included (a) 7-day physical activity monitoring using ActiGraph's GT3X accelerometers, (b) the evaluation of cognitive development, (c) anthropometric and physical fitness assessments, (d) plasma IGF-1 and BDNF concentrations, and (e) retrospective questionnaires. Linear regression models are used to examine the effect of physical activity on cognitive development; plasma IGF-1 and BDNF concentrations are considered as mediators into data analyses. The results of the study may help to inform future health interventions that utilize physical activity as a means to improve cognitive development in children, adolescents, and adults. Additionally, the study may assist in determining whether the putative effects occur via modification of plasma IGF-1 or BDNF concentrations.

Validity of proximity sensor-based wear-time detection using the ActiGraph GT9X

Our study investigated the performance of proximity sensor-based wear-time detection using the GT9X under laboratory and free-living settings. Fifty-two volunteers (23.2 ± 3.8 y; 23.2 ± 3.7 kg/m²) participated in either a laboratory or free-living protocol. Lab participants wore and removed a wrist-worn GT9X on 3-5 occasions during a 3-hour directly observed activity protocol. The 2-day free-living protocol used an independent temperature sensor and self-report as the reference to determine if wrist and hip-worn GT9X accurately determined wear (i.e., sensitivity) and non-wear (i.e., specificity). Free-living estimates of wear/non-wear were also compared to Troiano 2007 and Choi 2012 wear/non-wear algorithms. In lab, sensitivity and specificity of the wrist-worn GT9X in detecting total minutes of wear-on and off was 93% and 49%, respectively. The GT9X detected wear-off more often than wear-on, but with a greater margin of error (4.8 ± 11.6 vs. 1.4 ± 1.4 min). In the free-living protocol, wrist and hip-worn GT9X's yielded sensitivity and specificity of 72 and 90% and 84 and 92%, respectively. GT9X estimations had inferior sensitivity but superior specificity to Troiano 2007 and Choi 2012 algorithms. Due to inaccuracies, it may not be advisable to singularly use the proximity-sensor-based wear-time detection method to detect wear-time.

Association of Accelerometer-Measured Physical Activity With Leukocyte Telomere Length Among Older Women

Background

Previous studies on physical activity and telomere length have relied largely upon self-reported physical activity data, and few studies have examined older adults. The association of objectively measured physical activity with leukocyte telomere length (LTL) is currently unknown.

Methods

In this study, we examined cross-sectional associations between accelerometer-measured total, light, and moderate-to-vigorous physical activity (MVPA) and LTL, measured using Southern blot. The sample included 1,405 older (64-95 years old) white and African American women from the Women's Health Initiative. Multiple linear regression models adjusting for potential confounders were used to determine the association between accelerometer-measured physical activity and LTL.

Results

Overall, the mean (standard deviation) of total, light, and moderate-to-vigorous activity was 5.5 (1.6), 4.7 (1.3), and 0.8 (0.5) h/d, respectively. Adjusting for accelerometer wear time, age, race/ethnicity, education, marital status, smoking, alcohol, body mass index, a history of chronic diseases, and hormone therapy use, LTL was 80 (95% confidence interval: 9, 150) base pairs longer among women with ≥2.5 compared with <2.5 h/wk of MVPA. Light activity was not significantly associated with LTL. For total activity, the most physically active women had significantly longer LTL than the least active women after adjustment for demographic and lifestyle characteristics; however, findings were not significant after further adjustment for health-related factors.

Conclusions

Older women meeting current recommendations of ≥2.5 h/wk of MVPA, as assessed by accelerometer, had longer LTL. Additional studies using accelerometers in large, diverse cohorts of older women are needed to confirm and extend these findings.

Accelerometer-Measured Moderate to Vigorous Physical Activity and Incidence Rates of Falls in Older Women

OBJECTIVES

To examine whether moderate to vigorous physical activity (MVPA) measured using accelerometry is associated with incident falls and whether associations differ according to physical function or history of falls.

DESIGN

Prospective study with baseline data collection from 2012 to 2014 and 1 year of follow-up.

SETTING

Women's Health Initiative participants living in the United States.

PARTICIPANTS

Ambulatory women aged 63 to 99 (N = 5,545).

MEASUREMENTS

Minutes of MVPA per day measured using an accelerometer, functional status measured using the Short Physical Performance Battery (SPPB), fall risk factors assessed using a questionnaire, fall injuries assessed in a telephone interview, incident falls ascertained from fall calendars.

RESULTS

Incident rate ratios (IRRs) revealed greater fall risk in women in the lowest quartile of MVPA compared to those in the highest (IRR = 1.18, 95% confidence interval = 1.01-1.38), adjusted for age, race and ethnicity, and fall risk factors. Fall rates were not significantly associated with MVPA in women with high SPPB scores (9-12) or one or fewer falls in the previous year, but in women with low SPPB scores (≤ 8) or a history of frequent falls, fall rates were higher in women with lower MVPA levels than in those with higher levels (interaction P < .03 and < .001, respectively). Falls in women with MVPA above the median were less likely to involve injuries requiring medical treatment (9.9%) than falls in women with lower MVPA levels (13.0%) (P < .001).

CONCLUSION

These findings indicate that falls are not more common or injurious in older women who engage in higher levels of MVPA. These findings support encouraging women to engage in the amounts and types of MVPA that they prefer. Older women with low physical function or frequent falls with low levels of MVPA are a high-risk group for whom vigilance about falls prevention is warranted.

Protective and Harmful Effects of Physical Activity for Low Back Pain: A Protocol for the AUstralian Twin BACK Pain (AUTBACK) Feasibility Study

Low back pain (LBP) is a major health problem globally, but approaches to prevention are not yet clearly identified because modifiable risk factors are not well established. Although physical activity is one promising modifiable risk factor, it is still not known what types and doses of physical activity are protective or harmful for LBP. The aim of this study is to establish the feasibility of a definitive cohort study that will investigate the effects of different types and doses of physical activity on the risk of developing recurrent LBP while accounting for genetic factors. This will be a pilot longitudinal twin study and twins will be recruited from the Australian Twin Registry, and will be followed over 1 year. Thirty adult complete twin pairs with a history of LBP, but symptom free at recruitment, will be included. Data on physical activity (predictor) will be collected using four questionnaires and an objective measure (accelerometer) at baseline and at 6-month follow-up. Twins will also complete an additional physical activity questionnaire monthly. Data on LBP (outcome) will be collected at baseline and weekly. Data will be collected using short message service (SMS) and email. We will keep records of the recruitment rate, follow-up rate, and completeness of data. Barriers to completing the study will be investigated. The results of this study will inform the design and implementation of a future definitive study, which will help to clarify the effects of different types and doses of physical activity on the risk of developing recurrent LBP.

Testing the comparative effects of physical activity advice by humans vs. computers in underserved populations: The COMPASS trial design, methods, and baseline characteristics

While physical inactivity is a key risk factor for a range of chronic diseases and conditions associated with aging, a significant proportion of midlife and older adults remain insufficiently active. This is particularly true for ethnic minority populations such as Latino adults for whom few culturally adapted programs have been developed and tested. The major objective of this 12-month cluster-randomized controlled trial is to test the comparative effectiveness of two linguistically and culturally adapted, community-based physical activity interventions with the potential for broad reach and translation. Ten local community centers serving a sizable number of Latino residents were randomized to receive one of two physical activity interventions. The Virtual Advisor program employs a computer-based embodied conversational agent named "Carmen" to deliver interactive, individually tailored physical activity advice and support. A similar intervention program is delivered by trained Peer Advisors. The target population consists of generally healthy, insufficiently active Latino adults ages 50years and older living within proximity to a designated community center. The major outcomes are changes in walking and other forms of physical activity measured via self-report and accelerometry. Secondary outcomes include physical function and well-being variables. In addition to these outcome analyses, comparative cost analysis of the two programs, potential mediators of intervention success, and baseline moderators of intervention effects will be explored to better determine which subgroups do best with which type of intervention. Here we present the study design and methods, including recruitment strategies and yield as well as study baseline characteristics.

TRIAL REGISTRATION

clinicaltrial.gov Identifier=NCT02111213.

Is there a relationship between accelerometer-assessed physical activity and sedentary behavior and cognitive function in US Hispanic/Latino adults? The Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Normative changes in cognitive function are expected with increasing age. Research on the relationship between normative cognitive decline and moderate-to-vigorous physical activity (MVPA) and sedentary behavior (SED) needs further investigation in Hispanic/Latinos adults. We assessed the cross-sectional association between accelerometer assessed MVPA and SED with cognitive function in 7,478 adults aged 45-74years from the Hispanic Community Health Study/Study of Latinos. At baseline, cognitive tests included two executive function tests (Digit Symbol Substitution Test (DSST), a test of language (Word Fluency), and a test of memory (Spanish English Verbal Learning Test). Multiple regression models were used to examine associations of time spent in MVPA and SED with cognitive function by age groups, adjusted for age, education, sex, acculturation, and field center. Mean time spent in sedentary behaviors was 12.3h/day in females and 11.9 h/day in males (75% and 77% of accelerometer wear time, respectively). Higher SED, but not MVPA, was associated with lower DSST raw scores (β -0.03 with each 10-min increment in SED; P<0.05), indicating lower performance in executive function in all age groups. No associations were observed for MVPA and SED with tests of language or memory tests. Our findings suggest a distinct association of SED but not MVPA on executive functioning in middle-aged and older Latino adults. Longitudinal studies are needed to more conclusively determine causal links.

The relationship between moderate-to-vigorous physical activity and executive function among individuals with schizophrenia: differences by illness duration

OBJECTIVE

Schizophrenia is a chronic mental illness characterized by positive and negative symptoms. Cognitive impairment continues to be a core and consistent deficit. Previous studies have shown that physical activity (PA) is positively associated with cognitive performance. Thus, it may play a supportive role in mitigating cognitive impairments among individuals with schizophrenia. The aim of this study was to analyze the relationship between moderate-to-vigorous physical activity (MVPA) and executive function among adults with schizophrenia.

METHODS

The weekly amount of MVPA (assessed using accelerometers) and executive function (as per Brief Neurocognitive Assessment for Schizophrenia) of 78 adults with schizophrenia (mean [SD] age 42.4 [11.4] years; illness duration 17.0 [11.0] years; 58.2% male) were assessed in this cross-sectional study. Pearson correlations were calculated, followed by a linear regression. Participants were first analyzed together and then dichotomized on the basis of illness duration.

RESULTS

There was no significant association between MVPA and executive function, independent of the duration of illness. For individuals with < 15 years of illness, there was a significant association between weekly MVPA and working memory performance.

CONCLUSION

PA appears to be associated with executive function in some, but not all, individuals with schizophrenia.

Comparison of Sedentary Estimates between activPAL and Hip- and Wrist-Worn ActiGraph

PURPOSE

Sedentary behavior is an emerging independent health risk factor. The accuracy of measuring sedentary time using accelerometers may depend on the wear location. This study in older adults evaluated the accuracy of various hip- and wrist-worn ActiGraph accelerometer cutoff points to define sedentary time using the activPAL as the reference method.

METHODS

Data from 62 adults (mean age, 78.4 yr) of the Aging Research Evaluating Accelerometry study were used. Participants simultaneously wore an activPAL accelerometer on the thigh and ActiGraph accelerometers on the hip, dominant, and nondominant wrist for 7 d in a free-living environment. Using the activPAL as the reference criteria, we compared classification of sedentary time to hip-worn and wrist-worn ActiGraph accelerometers over a range of cutoff points for both 60-s and 15-s epochs.

RESULTS

The optimal cutoff point for the hip vertical axis was <22 counts per minute with an area under the curve (AUC) of 0.85; the optimal hip vector magnitude cutoff point was <174 counts per minute with an AUC of 0.89. For the dominant wrist, the optimal vector magnitude cutoff point to define sedentary time was <2303 counts per minute (AUC, 0.86) and for the nondominant wrist <1853 counts per minute (AUC, 0.86). The optimal 15-s cutoff points resulted in lower agreements compared with activPAL.

CONCLUSIONS

Hip- and wrist-worn ActiGraph data may be used to define sedentary time with a moderate to high accuracy when compared with activPAL. The observed optimal cutoff point for hip vertical axis <22 counts per minute is substantially lower than the standard <100 counts per minute. It is unknown how these optimal cutoff points perform in different populations. Results on an individual basis should therefore be interpreted with caution.

The Impact of Low Accelerometer Wear Time on the Estimates and Application of Sedentary Behavior and Physical Activity Data in Adults

BACKGROUND

This investigation sought to determine how accelerometer wear (1) biased estimates of sedentary behavior (SB) and physical activity (PA), (2) affected misclassifications for meeting the Physical Activity Guidelines for Americans, and (3) impacted the results of regression models examining the association between moderate to vigorous physical activity (MVPA) and a clinically relevant health outcome.

METHODS

A total of 100 participants [age: 20.6 (7.9) y] wore an ActiGraph GT3X+ accelerometer for 15.9 (1.6) hours per day (reference dataset) on the hip. The BOD POD was used to determine body fat percentage. A data removal technique was applied to the reference dataset to create individual datasets with wear time ranging from 15 to 10 hours per day for SB and each intensity of PA.

RESULTS

Underestimations of SB and each intensity of PA increased as accelerometer wear time decreased by up to 167.2 minutes per day. These underestimations resulted in Physical Activity Guidelines for Americans misclassification rates of up to 42.9%. The regression models for the association between MVPA and body fat percentage demonstrated changes in the estimates for each wear-time adherence level when compared to the model using the reference MVPA data.

CONCLUSIONS

Increasing accelerometer wear improves daily estimates of SB and PA, thereby also improving the precision of statistical inferences that are made from accelerometer data.

Effectiveness of a Behavior Change Program on Physical Activity and Eating Habits in Patients With Hypertension: A Randomized Controlled Trial

BACKGROUND

This study aimed to analyze the effect of a behavior change program, called Vida Ativa Melhorando a Saúde (VAMOS), on physical activity, eating habits, and quality of life in patients with hypertension.

METHODS

A randomized controlled trial was carried out in 90 patients with hypertension (57.8 ± 9.9 y). They were randomly assigned to 2 groups: VAMOS group (n = 45) and control group (n = 45). The VAMOS group participated in a behavioral change program aimed at motivating changes in physical activity and nutrition behavior for 12 weeks. Physical activity, eating habits, quality of life, self-efficacy, and social support were evaluated at preintervention and postintervention.

RESULTS

The control group increased sedentary time (407 ± 87 vs 303 ± 100 min/d; P < .05) and sedentary bouts (434 ± 86 vs 336 ± 98 min/d; P < .05) and reduced total physical activity (553 ± 87 vs 526 ± 86 min/d; P < .05). The VAMOS group improved the general healthy eating habits score (36.9 ± 6.6 vs 43.4 ± 5.8; P < .05) and quality of life (44% vs 92%; P < .05).

CONCLUSION

The VAMOS program was effective in improving eating habits and quality of life in patients with hypertension.

Sedentary Behaviors and Biomarkers Among Breast Cancer Survivors

BACKGROUND

Sedentary behavior is associated with increased risk of poor outcomes in breast cancer survivors, but underlying mechanisms are not well understood. This pilot study explored associations between different aspects of sedentary behaviors (sitting, prolonged sitting, sit-to-stand transitions, and standing) and breast cancer risk-related biomarkers in breast cancer survivors (n = 30).

METHODS

Sedentary behavior variables were objectively measured with thigh-worn activPALs. Breast cancer risk-related biomarkers assessed were C-reactive protein (CRP), insulin, and homeostatic model assessment of insulin resistance (HOMA-IR) and were measured in fasting plasma samples. Linear regression models were used to investigate associations between sedentary behavior variables and biomarkers (log CRP, insulin, and HOMA-IR).

RESULTS

Sit-to-stand transitions were significantly associated with insulin resistance biomarkers (P < .05). Specifically, each 10 additional sit-to-stand transitions per day was associated with a lower fasting insulin concentration (β = -5.52; 95% CI, -9.79 to -1.24) and a lower HOMA-IR value (β = -0.22; 95% CI, -0.42 to -0.03). Sit-to-stand transitions were not significantly associated with CRP concentration (P = .08). Total sitting time, long sitting bouts, and standing time were not significantly associated with CRP, insulin, or HOMA-IR (P > .05).

CONCLUSIONS

Sit-to-stand transitions may be an intervention target for reducing insulin resistance in breast cancer survivors, which may have favorable downstream effects on cancer prognosis.

The relations between sleep, time of physical activity, and time outdoors among adult women

Physical activity and time spent outdoors may be important non-pharmacological approaches to improve sleep quality and duration (or sleep patterns) but there is little empirical research evaluating the two simultaneously. The current study assesses the role of physical activity and time outdoors in predicting sleep health by using objective measurement of the three variables. A convenience sample of 360 adult women (mean age = 55.38 ±9.89 years; mean body mass index = 27.74 ±6.12) was recruited from different regions of the U.S. Participants wore a Global Positioning System device and ActiGraph GT3X+ accelerometers on the hip for 7 days and on the wrist for 7 days and 7 nights to assess total time and time of day spent outdoors, total minutes in moderate-to-vigorous physical activity per day, and 4 measures of sleep health, respectively. A generalized mixed-effects model was used to assess temporal associations between moderate-to-vigorous physical activity, outdoor time, and sleep at the daily level (days = 1931) within individuals. There was a significant interaction (p = 0.04) between moderate-to-vigorous physical activity and time spent outdoors in predicting total sleep time but not for predicting sleep efficiency. Increasing time outdoors in the afternoon (versus morning) predicted lower sleep efficiency, but had no effect on total sleep time. Time spent outdoors and the time of day spent outdoors may be important moderators in assessing the relation between physical activity and sleep. More research is needed in larger populations using experimental designs.

The Relationship Between Apolipoprotein ε4 Carrier Status and Sleep Characteristics in Cognitively Normal Older Adults

The apolipoprotein (APOE) ε4 allele, a well-described genetic risk factor for late-onset Alzheimer disease (AD), is associated with sleep disturbances even in cognitively normal older adults, although it is not clear whether this association is independent of sleep apnea. We sought to extend previous studies by examining whether cognitively normal older adults without self-reported sleep apnea who carry the APOE ε4 allele have altered sleep characteristics compared to noncarriers. Data from N = 36 (APOE ε4 carriers [n = 9], noncarriers [n = 27]) cognitively normal older adults (Clinical Dementia Rating [CDR] scale = 0) without self-reported sleep apnea were used for these analyses. Participants wore an actigraph for 7 days to determine sleep characteristics. The Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS) were used to assess sleep quality and daytime sleepiness, respectively. The APOE ε4 carriers had a higher number of awakenings compared to the noncarriers ( P = .02). There was no significant difference in the PSQI global score and the ESS; however, the PSQI subcomponent of daily disturbances was significantly higher in APOE ε4 carriers ( P = .03), indicating increased daytime dysfunction is related to disrupted sleep. This study provides evidence that individuals who are cognitively normal and genetically at risk of AD may have disrupted sleep. These findings are consistent with prior studies and suggest that sleep disruption may be present in the presymptomatic stages of AD.

Prolonged, Uninterrupted Sedentary Behavior and Glycemic Biomarkers Among US Hispanic/Latino Adults: The HCHS/SOL (Hispanic Community Health Study/Study of Latinos)

BACKGROUND

Excessive sedentary time is ubiquitous in developed nations and is associated with deleterious health outcomes. Few studies have examined whether the manner in which sedentary time is accrued (in short or long bouts) carries any clinical relevance. The purpose of this study was to examine the association of prolonged, uninterrupted sedentary behavior with glycemic biomarkers in a cohort of US Hispanic/Latino adults.

METHODS

We studied 12 083 participants from the HCHS/SOL (Hispanic Community Health Study/Study of Latinos), a population-based study of Hispanic/Latino adults 18 to 74 years of age. Homeostatic model assessment of insulin resistance and glycosylated hemoglobin were measured from a fasting blood sample, and 2-hour glucose was measured after an oral glucose tolerance test. Sedentary time was objectively measured with a hip-mounted accelerometer. Prolonged, uninterrupted sedentariness was expressed as mean sedentary bout length.

RESULTS

After adjustment for potential confounders and moderate to vigorous physical activity, longer sedentary bout duration was dose-dependently associated with increased homeostatic model assessment of insulin resistance (P for trend<0.001) and 2-hour glucose levels (P for trend=0.015). These associations were not independent of total sedentary time; however, a significant interaction between sedentary bout duration and total sedentary time was observed. Evaluation of the joint association of total sedentary time and sedentary bout duration showed that participants in the upper quartile for both sedentary characteristics (ie, high total sedentary time and high sedentary bout duration) had the highest levels of homeostatic model assessment of insulin resistance (P<0.001 versus low group for both sedentary characteristics) and 2-hour glucose (P=0.002 versus low group for both sedentary characteristics). High total sedentary time or high sedentary bout duration alone were not associated with differences in any glycemic biomarkers.

CONCLUSIONS

Accruing sedentary time in prolonged, uninterrupted bouts may be deleteriously associated with biomarkers of glucose regulation.

Deriving a GPS Monitoring Time Recommendation for Physical Activity Studies of Adults

INTRODUCTION

Determining locations of physical activity (PA) is important for surveillance and intervention development, yet recommendations for using location recording tools like global positioning system (GPS) units are lacking. Specifically, no recommendation exists for the number of days study participants should wear a GPS to reliably estimate PA time spent in locations.

METHODS

This study used data from participants (N = 224, age = 18-85 yr) in five states who concurrently wore an ActiGraph GT1M accelerometer and a Qstarz BT-Q1000X GPS for three consecutive weeks to construct monitoring day recommendations through variance partitioning methods. PA bouts ≥10 min were constructed from accelerometer counts, and the location of GPS points was determined using a hand-coding protocol.

RESULTS

Monitoring day recommendations varied by the type of location (e.g., participant homes vs parks) and the intensity of PA bouts considered (low and medium cut point moderate to vigorous PA [MVPA] bouts or high cut point vigorous PA [VPA] bouts). In general, minutes of all PA intensities spent in a given location could be measured with ≥80% reliability using 1-3 d of GPS monitoring for fitness facilities, schools, and footpaths. MVPA bout minutes in parks and roads required longer monitoring periods of 5-12 d. PA in homes and commercial areas required >19 d of monitoring.

CONCLUSIONS

Twelve days of monitoring was found to reliably estimate minutes in both low and medium threshold MVPA as well as VPA bouts for many important built environment locations that can be targeted to increase PA at the population level. Minutes of PA in the home environment and commercial locations may be best assessed through other means given the lengthy estimated monitoring time required.

Objectively measured physical activity patterns, sedentary time and parent-reported screen-time across the day in four-year-old Swedish children

Background

Physical activity (PA) improves health outcomes accumulating evidence suggests that sedentary time (ST), especially parent-reported screen-time, is associated with negative health outcomes in children. The aim of the present study is to describe levels and patterns of PA and ST across the day and week and activity pattern differences between the sexes, across all weekdays and time spent in and outside the preschool in four-year old children.

Methods

In total 899 four-year old Swedish children who had both complete questionnaire data on screen-time behaviors and objective activity variables and at least 4 days, including one weekend day, with more than 10 h of GT3X+ Actigraph accelerometer wear time data were included in the study. Patterns of PA and ST across the day and week and differences between sexes, weekdays vs. weekend days and time in preschool vs. time spent outside preschool were assessed.

Results

Children engaged in 150 min (SD 73) and 102 min (SD 60) of screen-time on weekend days and weekdays, with 97% and 86% of children exceeding the 1 h guideline for screen-time on weekend days and weekdays, respectively. Accelerometer data showed that boys are more active and less sedentary compared with girls and both sexes were more active and less sedentary on weekdays compared with weekend days, while parent-reported data showed that boys engage in more screen-time compared with girls. Children accumulated 24.8 min (SD. 19) MVPA during preschool time and 26.6 min (SD. 16) outside preschool hours on weekdays, compared with 22.4 min (SD. 18) MVPA during preschool time and 25.3 min (SD. 22) outside preschool hours on weekend days.

Conclusions

Four-year old Swedish children display different activity patterns across the day on weekdays compared to weekend days, with preschool hours during weekdays being the most active segments and preschool hours during weekend days being the least active segments of the day.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-017-4600-5) contains supplementary material, which is available to authorized users.

Re-evaluating the effect of age on physical activity over the lifespan

Advancements in accelerometer analytic and visualization techniques allow researchers to more precisely identify and compare critical periods of physical activity (PA) decline by age across the lifespan, and describe how daily PA patterns may vary across age groups. We used accelerometer data from the 2003-2006 cohorts of the National Health and Nutrition Examination Survey (NHANES) (n=12,529) to quantify total PA as well as PA by intensity across the lifespan using sex-stratified, age specific percentile curves constructed using generalized additive models. We additionally estimated minute-to-minute diurnal PA using smoothed bivariate surfaces. We found that from childhood to adolescence (ages 6-19) across sex, PA is sharply lower by age partially due to a later initiation of morning PA. Total PA levels, at age 19 are comparable to levels at age 60. Contrary to prior evidence, during young adulthood (ages 20-30) total and light intensity PA increases by age and then stabilizes during midlife (ages 31-59) partially due to an earlier initiation of morning PA. We additionally found that males compared to females have an earlier lowering in PA by age at midlife and lower total PA, higher sedentary behavior, and lower light intensity PA in older adulthood; these trends seem to be driven by lower PA in the afternoon compared to females. Our results suggest a re-evaluation of how emerging adulthood may affect PA levels and the importance of considering time of day and sex differences when developing PA interventions.

Accelerometer-measured sedentary behaviour and physical activity of inpatients with severe mental illness

Sedentary behaviour and lack of physical activity threatens health. Research concerning these behaviours of inpatients with severe mental illness is limited but urgently needed to reveal prevalence and magnitude. In total, 184 inpatients (men n =108, women n =76, mean age 57,4, 20% first generation antipsychotics, 40% second generation antipsychotics, 43% antidepressants, mean years hospitalisation 13 years), with severe mental illness of a Dutch psychiatric hospital wore an accelerometer for five days to objectively measure total activity counts per hour and percentages in sedentary behaviour, light intensity physical activity and moderate to vigorous physical activity. Accelerometer data were compared with data of 54 healthy ward employees. Patients showed significantly less activity counts per hour compared to employees (p=0.02), although the differences were small (d=0.32). Patients were sedentary during 84% of the wear time (50min/h), spend 10% in light intensity physical activity and 6% in moderate to vigorous physical activity. Age was the only significant predictor, predicting less total activity counts/h in higher ages. Decreasing sedentary behaviour and improving physical activity in this population should be a high priority in clinical practice.

The Association of Parental/Caregiver Chronic Stress with Youth Obesity: Findings from the Study of Latino Youth and the Hispanic Community Health Study/Study of Latinos Sociocultural Ancillary Study

BACKGROUND

Prior studies indicate that chronic stress is associated with obesity in adults. However, whether parental/caregiver stress is associated with obesity in their offspring has not been widely examined in Hispanic/Latino populations. In this study, we evaluated the role of caregiver chronic stress on child obesity and whether home food environment or child lifestyle behaviors explained the association.

METHODS

The study included a sample of Hispanic/Latino youth and their caregivers (n = 473) from the Study of Latinos (SOL) Youth study and the Hispanic Community Health Study/SOL Sociocultural Study, which enrolled children aged 8-16 years from four cities (Bronx, Chicago, Miami, and San Diego), and provided assessments of adult chronic stress. Poisson regression models were used to assess the association between parental/caregiver stress and child obesity, adjusting for potential confounders.

RESULTS

Twenty-two percent of caregivers did not report any chronic stressors, 48% reported 1-2, and 29% reported ≥3 stressors. The prevalence of obesity in youth increased with number of caregiver stressors from 23% among those without caregiver stressors to 35% among those with ≥3 stressors (p for trend 0.03). After model adjustment, youths whose caregivers reported ≥3 stressors were more likely to be obese than youths whose caregivers reported no stressors (prevalence ratio = 1.53; 95% confidence interval 1.01-2.32). This association was independent of food home environment, child diet quality, and child physical activity, but it was not independent of caregiver obesity.

CONCLUSIONS

These findings suggest that parental/caregiver chronic stress is related to obesity in their children. Future research is needed to confirm this association in longitudinal studies and in other population groups.

Where Are Adults Active? An Examination of Physical Activity Locations Using GPS in Five US Cities

Increasing physical activity (PA) at the population level requires appropriately targeting intervention development. Identifying the locations in which participants with various sociodemographic, body weight, and geographic characteristics tend to engage in varying intensities of PA as well as locations these populations underutilize for PA may facilitate this process. A visual location-coding protocol was developed and implemented in Google Fusion Tables and Maps using data from participants (N = 223, age 18-85) in five states. Participants concurrently wore ActiGraph GT1M accelerometers and Qstarz BT-Q1000X GPS units for 3 weeks to identify locations of moderate-to-vigorous (MVPA) or vigorous (VPA) bouts. Cochran-Mantel-Haenzel general association tests examined usage differences by participant characteristics (sex, age, race/ethnicity, education, body mass index (BMI), and recruitment city). Homes and roads encompassed >40% of bout-based PA minutes regardless of PA intensity. Fitness facilities and schools were important for VPA (19 and 12% of bout minutes). Parks were used for 13% of MVPA bout minutes but only 4% of VPA bout minutes. Hispanics, those without a college degree, and overweight/obese participants frequently completed MVPA bouts at home. Older adults often used roads for MVPA bouts. Hispanics, those with ≤high school education, and healthy/overweight participants frequently had MVPA bouts in parks. Applying a new location-coding protocol in a diverse population showed that adult PA locations varied by PA intensity, sociodemographic characteristics, BMI, and geographic location. Although homes, roads, and parks remain important locations for demographically targeted PA interventions, observed usage patterns by participant characteristics may facilitate development of more appropriately targeted interventions.

Physical Activity in Pediatric Pulmonary Arterial Hypertension Measured by Accelerometry. A Candidate Clinical Endpoint

RATIONALE

The development of evidence-based treatment guidelines for pediatric pulmonary arterial hypertension (PAH) is hampered by lack of pediatric clinical trials. Trial design is hampered by lack of a feasible clinical endpoint in this population.

OBJECTIVES

To evaluate the use of accelerometry for measuring physical activity (PA) in pediatric PAH and to investigate its correlation with clinical disease severity markers.

METHODS

We included children from the Dutch National Network for Pediatric Pulmonary Hypertension. Control patients were recruited from the outpatient cardiology clinic of the Beatrix Children's Hospital. Children were asked to wear the accelerometer for 7 days. Vector magnitude counts per minute (VM CPM) and time per day spent in different PA intensity levels were defined as accelerometer outcomes.

MEASUREMENTS AND MAIN RESULTS

VM CPM was lower in children with PAH (n = 29) than in controls (n = 60; 647 vs. 921; P < 0.001). Children with PAH spent less time in moderate and vigorous PA (13 vs. 29 min/d and 2 vs. 13 min/d, respectively; P < 0.001). Time spent in moderate and vigorous PA correlated inversely with World Health Organization functional class. Time spent in moderate PA correlated positively with 6-minute-walk distance. In post hoc analyses, VM CPM and time spent in moderate/vigorous combined and vigorous PA were associated with outcome (P ≤ 0.044).

CONCLUSIONS

PA is markedly decreased in children with PAH. Accelerometer output correlated with clinical disease severity markers and may predict outcome. We showed an exciting potential of PA as a meaningful endpoint for clinical trials in pediatric PAH, although its clinical utility and prognostic value need to be further validated.

Reallocating bouted sedentary time to non-bouted sedentary time, light activity and moderate-vigorous physical activity in adults with prediabetes and type 2 diabetes

Aim

The aim of this study was to investigate the potential associations of reallocating 30 minutes sedentary time in long bouts (>60 min) to sedentary time in non-bouts, light intensity physical activity (LPA) and moderate- to vigorous physical activity (MVPA) with cardiometabolic risk factors in a population diagnosed with prediabetes or type 2 diabetes.

Methods

Participants diagnosed with prediabetes and type 2 diabetes (n = 124, 50% men, mean [SD] age = 63.8 [7.5] years) were recruited to the physical activity intervention Sophia Step Study. For this study baseline data was used with a cross-sectional design. Time spent in sedentary behaviors in bouts (>60 min) and non-bouts (accrued in <60 min bouts) and physical activity was measured using the ActiGraph GT1M. Associations of reallocating bouted sedentary time to non-bouted sedentary time, LPA and MVPA with cardiometabolic risk factors were examined using an isotemporal substitution framework with linear regression models.

Results

Reallocating 30 minutes sedentary time in bouts to MVPA was associated with lower waist circumference (b = -4.30 95% CI:-7.23, -1.38 cm), lower BMI (b = -1.46 95% CI:-2.60, -0.33 kg/m2) and higher HDL cholesterol levels (b = 0.11 95% CI: 0.02, 0.21 kg/m². Similar associations were seen for reallocation of sedentary time in non-bouts to MVPA. Reallocating sedentary time in bouts to LPA was associated only with lower waist circumference.

Conclusion

Reallocation of sedentary time in bouts as well as non-bouts to MVPA, but not to LPA, was beneficially associated with waist circumference, BMI and HDL cholesterol in individuals with prediabetes and type 2 diabetes. The results of this study confirm the importance of reallocation sedentary time to MVPA.

How active are women who play bingo: a cross-sectional study from the Well!Bingo project

BACKGROUND

The benefits of physical activity are well established, yet large numbers of people are not sufficiently active to gain health benefits. Certain population groups are less physically active than others, including older women from areas of high economic deprivation. The Well!Bingo project was established with the aim of engaging such women in the development of a health promotion intervention in a bingo club. This paper reports on the assessment of health status, physical activity and sedentary behaviour of women attending a bingo club in central Scotland, UK as part of the Well!Bingo project.

METHODS

Women attending the bingo club were invited to provide information on demographic characteristics, and self-reported physical activity and sedentary behaviour via a self-complete questionnaire as part of a cross-sectional study (n = 151). A sub-sample (n = 29) wore an accelerometer for an average of 5.7 ± 1.4 days. Differences between younger (under 60 years) and older adults (60 years and over) were assessed using a chi-square test for categorical data and the independent samples t-test was used to assess continuous data (p < 0.05).

RESULTS

The mean age was 56.5 ± 17.7 years, with 57% living in areas of high deprivation (Scottish Index of Multiple Deprivation quintile one and two). Sixty-three percent of women (n = 87) reported they were meeting physical activity guidelines. However, objective accelerometer data showed that, on average, only 18.1 ± 17.3 min a day were spent in moderate to vigorous physical activity. Most accelerometer wear time was spent sedentary (9.6 ± 1.7 h). For both self-report and accelerometer data, older women were significantly less active and more sedentary than younger women. On average, older women spent 1.8 h more than younger women in sedentary activities per day, and took part in 21 min less moderate to vigorous physical activity (9.4 mins per day).

CONCLUSION

The findings of this study suggest that bingo clubs are settings that attract women from areas of high deprivation and older women in bingo clubs in particular would benefit from interventions to target their physical activity and sedentary behaviour. Bingo clubs may therefore be potential intervention settings in which to influence these behaviours.

Randomized controlled trial on the effects of a supervised high intensity exercise program in patients with a hematologic malignancy treated with autologous stem cell transplantation: Results from the EXIST study

BACKGROUND

This single blind, multicenter randomized controlled trial aimed to evaluate the effectiveness of a supervised high intensity exercise program on physical fitness and fatigue in patients with multiple myeloma or lymphoma recently treated with autologous stem cell transplantation.

METHODS

109 patients were randomly assigned to the 18-week exercise intervention or the usual care control group. The primary outcomes included physical fitness (VO2peak and Wpeak determined using a cardiopulmonary exercise test; grip strength and the 30s chair stand test) and fatigue (Multidimensional Fatigue Inventory) and were assessed prior to randomization and after completion of the intervention or at similar time points for the control group. Multivariable multilevel linear regression analyses were performed to assess intervention effects.

RESULTS

Patients in the intervention group attended 86% of the prescribed exercise sessions. Of the patients in the control group, 47% reported ≥10 physiotherapy sessions, which most likely included supervised exercise, suggesting a high rate of contamination. Median improvements in physical fitness ranged between 16 and 25% in the intervention group and between 12 and 19% in the control group. Fatigue decreased in both groups. There were no significant differences between the intervention and control group.

CONCLUSION

We found no significant beneficial effects of the supervised high intensity exercise program on physical fitness and fatigue when compared to usual care. We hypothesized that the lack of significant intervention effects may relate to suboptimal timing of intervention delivery, contamination in the control group and/or suboptimal compliance to the prescribed exercise intervention.

TRIAL REGISTRATION

Netherlands Trial Register-NTR2341.

Objectively Measured Physical Activity in Patients After Anterior Cruciate Ligament Reconstruction

BACKGROUND

Returning to a healthy level of physical activity is among the most commonly discussed clinical goals for patients recovering from anterior cruciate ligament reconstruction (ACLR). However, physical activity has not been objectively measured in this population.

PURPOSE

To investigate differences in the mean time (min/d) spent in moderate-to-vigorous physical activity (MVPA) as well as the daily step count (steps/d) between patients who underwent ACLR and matched controls. A second purpose was to investigate relationships between MVPA and objective assessments of the daily step count and Tegner and Marx activity scales.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Physical activity was assessed using ActiGraph accelerometers in 33 participants with a history of primary unilateral or bilateral ACLR (mean time from surgery, 27.8 ± 17.5 months; range, 6-67 months) as well as in 33 healthy controls (matched on age, sex, and activity level). Participants wore the accelerometer for 7 days and completed the International Knee Documentation Committee subjective form and the Tegner and Marx activity scales. Independent t tests were used to determine differences in each dependent variable per group.

RESULTS

Patients who underwent ACLR spent less time in MVPA (ACLR: 79.37 ± 23.95 min/d; control: 93.12 ± 23.94 min/d; P = .02) and had a lower daily step count (ACLR: 8158 ± 2780 steps/d; control: 9769 ± 2785 steps/d; P = .02) compared with healthy matched controls. However, the Marx (ACLR median: 11.0 [interquartile range (IQR), 7-14]; control median: 12.0 [IQR, 8-13]; P = .85) and Tegner (ACLR median: 6.0 [IQR, 5-8]; control median: 7.0 [IQR, 6-8]; P = .12) scores did not differ between the groups, and no relationships were observed between objectively measured physical activity and scale measures ( P > .05), except for a moderate relationship between the Tegner score and daily step count in the ACLR group ( r = 0.36, P = .04). Only 24% of patients who underwent ACLR met the guideline of 10,000 steps per day compared with 42% of controls.

CONCLUSION

Patients who underwent ACLR spent less time in MVPA and had a lower daily step count compared with highly matched controls (age, sex, and activity level) with no history of knee injuries. This was true despite being similar in activity levels, which brings into question the utility of the Tegner and Marx activity scales.