Self-supervised learning of accelerometer data provides new insights for sleep and its association with mortality.

Sleep is essential to life. Accurate measurement and classification of sleep/wake and sleep stages is important in clinical studies for sleep disorder diagnoses and in the interpretation of data from consumer devices for monitoring physical and mental well-being. Existing non-polysomnography sleep classification techniques mainly rely on heuristic methods developed in relatively small cohorts. Thus, we aimed to establish the accuracy of wrist-worn accelerometers for sleep stage classification and subsequently describe the association between sleep duration and efficiency (proportion of total time asleep when in bed) with mortality outcomes. We developed a self-supervised deep neural network for sleep stage classification using concurrent laboratory-based polysomnography and accelerometry. After exclusion, 1448 participant nights of data were used for training. The difference between polysomnography and the model classifications on the external validation was 34.7 min (95% limits of agreement (LoA): -37.8-107.2 min) for total sleep duration, 2.6 min for REM duration (95% LoA: -68.4-73.4 min) and 32.1 min (95% LoA: -54.4-118.5 min) for NREM duration. The sleep classifier was deployed in the UK Biobank with 100,000 participants to study the association of sleep duration and sleep efficiency with all-cause mortality. Among 66,214 UK Biobank participants, 1642 mortality events were observed. Short sleepers (<6 h) had a higher risk of mortality compared to participants with normal sleep duration of 6-7.9 h, regardless of whether they had low sleep efficiency (Hazard ratios (HRs): 1.58; 95% confidence intervals (CIs): 1.19-2.11) or high sleep efficiency (HRs: 1.45; 95% CIs: 1.16-1.81). Deep-learning-based sleep classification using accelerometers has a fair to moderate agreement with polysomnography. Our findings suggest that having short overnight sleep confers mortality risk irrespective of sleep continuity.

Associations between physical activity, sedentary behaviour and cognitive domain performance of people living with mild cognitive impairment in the community.

INTRODUCTION: Physical activity is known to positively influence cognitive performance. For adults with mild cognitive impairment (MCI), the relationship between physical activity levels and cognitive performance is unknown. This cross-sectional study aimed to determine if cognitive performance [as measured by the Montreal Cognitive Assessment (MoCA)] of people living in the community with MCI is associated with their physical activity levels or sedentary behaviour. METHODS: ActivPAL™ accelerometers were used to objectively measure physical activity and sedentary behaviour for seven full days. Cognitive performance was measured using the MoCA. CONSUMER AND COMMUNITY INVOLVEMENT: No involvement other than as research participants RESULTS: Eighty-two participants from the Balance on the Brain randomised controlled trial were included. Most participants were retired (88%), with 33 (40%) reporting a fall in the last year. The median MoCA score was 24 (IQR 22-26). Participants achieved a mean of 6296 (±2420) steps per day and were sedentary for 10.6 (±2) hours per day. The only physical activity outcomes that had a fair, positive correlation were moderate- to vigorous-intensity physical activity measures of total stepping time and total number of steps (with a cadence of ≥100 steps/min) with the orientation MoCA domain score (r(82) = 0.36, p ≤ 0.001 and r(82) = 0.37, p ≤ 0.001, respectively). Higher total sedentary time had a weak, positive correlation with better visuospatial/executive performance (r(82) = 0.23, p = 0.041). The orientation outcomes remained significant when analysed in an adjusted logistic regression model. CONCLUSION: This study found that performance in the MoCA orientation domain had a fair-positive correlation with moderate-intensity physical activity (i.e., stepping time and step count with a cadence of ≥100 steps/min) as measured by a thigh-worn accelerometer for community-dwelling older adults with MCI. When considering the relationship between cognitive domains and sedentary behaviour, consideration may be needed regarding whether cognitive enhancing activities (such as crosswords and other brain games) are being performed, which may confound this relationship. Further investigation is required to confirm these results.

Physical Activity Levels and Sedentary Behavior of People Living With Mild Cognitive Impairment: A Cross-Sectional Study Using Thigh-Worn Accelerometers.

Community-dwelling people with Mild Cognitive Impairment self-reporting not to be meeting recommended physical activity levels participated in this study to (a) determine compliance of wearing (thigh-worn) accelerometers, (b) describe physical activity levels and sedentary behavior, and (c) determine the validity of the Physical Activity Scale for the Elderly (PASE) compared with activPAL accelerometers. A total of 79 people had valid accelerometer data (median [interquartile range]: age, 71 [54-75] years). Compliance was 86.81%. Participants were sedentary for 10.6 hr per day and engaged in a median of 9 min per day of moderate-intensity physical activity. Fair correlations were found between the PASE and total stepping time per day (r = .35, p < .01), total number of steps per day (r = .36, p < .01), and number of steps in stepping activities completed for ≤1 min (r = .42, p < .01). The PASE and Standing time (r = .04, p = .724) and PASE and Sitting time (r = .04, p = .699) had little to no relationship. The use of thigh-worn accelerometers for this population is achievable. People with Mild Cognitive Impairment have high levels of sedentary behavior and minimal engagement in moderate-intensity physical activity. The PASE has fair, positive criterion validity with activity-based outcomes measured by activPAL accelerometers but not with sedentary behavior, which is high for this population.

Barriers and Facilitators to Participation in Vigorous Lifestyle Physical Activity in Adults Aged 55-75 Years: A Scoping Review.

Despite the well-known benefits of physical activity, less than half of adults aged 55-75 years participate in sufficient physical activity. Short bouts of vigorous intermittent lifestyle physical activity (VILPA) accumulated throughout the day can contribute toward the recommended volume of physical activity. A rich characterization of the barriers and facilitators to participation in VILPA is needed to develop targeted interventions. This scoping review aimed to identify barriers and facilitators to participation in different components of VILPA in adults aged 55-75 years, and to map barriers and facilitators to the Theoretical Domains Framework. Within the 18 eligible studies, the most prevalent barriers were related to a person's skills, environmental context, and social influences. Most facilitators were related to a person's goals, social influences, and environmental context. Interventions to promote VILPA should test the effectiveness of behavioral change measures related to the unique barriers and facilitators in this age group.

Relationships between physical behaviour phenotypes of mothers in pregnancy and their offspring with child body composition.

AIM: The aim of this study was to identify physical behaviour phenotypes in mothers in the first trimester and in their offspring at 24 months of age. The secondary aim was to examine relationships between mother and child behaviours with child body composition at age 24 months. METHODS: Longitudinal secondary analysis of the Glowing cohort collected between 1 February 2011 and 22 August 2017 in Little Rock, Arkansas. Behaviours were measured using ankle-worn accelerometers in mothers during the first trimester and offspring at 24 months of age, including total activity, sleep, sedentary time and a novel variable of daily variation, patternicity. Child body fat was measured using quantitative nuclear magnetic resonance. RESULTS: Three phenotypes were identified for mothers and children (n = 159 complete dyads). There were no relationships between mother and child phenotypes, but higher maternal patternicity was associated with higher child patternicity (0.2, 95% CI 0.1, 0.3, p = 0.001). There were no associations between mother or child phenotypes with child body composition, however higher child activity was associated with lower body fat (-0.01, 95% CI: -0.02, -0.001, p = 0.031). CONCLUSION: Limited associations were found between mothers' pregnancy physical behaviours with child behaviours or child body composition at 24 months of age. Factors such as child diet or current parental physical activity may be better predictors of early childhood outcomes.

Relationship between TV Watching during Childhood and Adolescence, and Artery Function in Adulthood.

PURPOSE: Artery dysfunction is an early, integral stage in atherogenesis that predicts future cardiovascular events. Sedentary behavior, such as TV watching, is highly prevalent and associated with increased risk of developing cardiovascular diseases. This study investigated whether patterns of TV watching throughout childhood and adolescence were associated with artery function in adulthood. METHODS: TV watching data were collected when participants of the Raine Study were aged 5, 8, 10, 14, 17, and 20 yr. Previous latent class analysis indicated three trajectory groups of TV watching: low TV (<14 h·wk -1 ), high TV (>14 h·wk -1 ), and increasing TV (change from low TV to high TV). At age 28 yr, participants were invited to undergo tests of brachial and femoral artery function by flow-mediated dilation (FMD). General linear models examined differences in artery function between TV trajectory groups for men and women. RESULTS: Five hundred sixty participants (n = 261 women, n = 299 men) were included in the study. In women, the low TV group had significantly greater femoral artery FMD (10.8 ± 1.6%) than both High TV (9.0 ± 1.3%, P = 0.005) and Increasing TV groups (8.5 ± 1.3%, P < 0.001); these results were maintained following mediation analysis, including contemporaneous risk factors. There were no significant differences in femoral artery FMD between TV trajectory groups in men ( P = 0.955). CONCLUSIONS: This study suggests that TV watching behaviors during childhood and adolescence may have legacy impacts on artery function at age 28 yr, particularly in women. This may increase the risk of atherosclerotic vascular pathologies in later life.

Association between Physical Activity and Reduced Mortality in Inoperable Lung Cancer.

We examined device-measured physical activity (PA) and sedentary behaviour at the time of diagnosis in people with inoperable lung cancer and investigated their associations with 12-month mortality. The people with inoperable lung cancer wore an accelerometer for seven days prior to the treatment commencement. The analysed PA/sedentary behaviour variables included light-intensity PA, moderate-to-vigorous-intensity PA (MVPA), step count, the total time spent sedentary, and the usual sedentary bout duration. The data on the disease stage, clinical covariates and 12-month mortality were extracted from medical records. Cox regression models were used to estimate the association between the PA measures and 12-month mortality, and the sedentary behaviour measures and 12-month mortality. The models were adjusted for the stage and neutrophil-to-lymphocyte ratio. All the PA and sedentary behaviour variables were dichotomised at their medians for analysis. Eighty-nine participants (70 ± 10 years; 55 [62%] males) contributed valid data. The twelve-month mortality was 30% (n = 27). Compared to the participants who spent ≤4.6 min/day in MVPA (n = 45), those who spent >4.6 min/day (n = 44) had a relative risk of 12-month mortality reduced by 60% (hazard ratio, 0.40; 95% CI, 0.16 to 0.96; 18 versus nine deaths, respectively). The other variables of PA/sedentary behaviour were not associated with 12-month mortality. Higher device-measured MVPA was associated with reduced 12-month mortality in people who were newly diagnosed with inoperable lung cancer.

Health behaviour profiles in young Australian adults in relation to physical and mental health: The Raine Study.

ISSUES ADDRESSED: We aimed to identify latent health behaviour profiles of young adults and examine their associations with physical and mental health outcomes. We also characterised the profiles by socio-demographic characteristics. METHODS: Data were collected between 2012 and 2014. Participants (N = 476) were young adults (M age [SD] = 22.1 [.57] years) from Generation 2 of the Raine Study longitudinal cohort. Health behaviours were measured via ActiGraph GT3X waist monitors (physical activity, sedentary behaviour) and questionnaires (diet quality, alcohol, smoking and sleep). Physical and mental health were measured using clinical health assessments, blood biomarkers, and questionnaires. Latent Profile Analysis using Mplus (8.2) was employed to identify profiles. RESULTS: Four latent profiles were identified: 'heavy drinkers with moderately unhealthy eating habits' (high takeaway foods; n = 135), 'unhealthy food abstainers' (low takeaway foods; n = 138), 'moderately sedentary alcohol abstainers' (n = 139) and 'physically active drinkers with unhealthy eating habits' (high takeaway foods and sugary drinks; n = 64). 'Physically active drinkers with unhealthy eating habits' had the poorest (physical and mental) health outcomes, yet the lowest insulin resistance. 'Unhealthy food abstainers' had the most favourable health outcomes (adiposity, health perceptions, blood pressure). Sex differed among the profiles. CONCLUSIONS: The profiles identified among young adults are different to profiles with general adult populations. A novel finding was that 'physically active drinkers with unhealthy eating habits' had low insulin resistance. The findings also suggest that future interventions may need to be sex specific. SO WHAT: Our findings suggest that health behaviour interventions for young adults should be targeted to distinct profile characteristics.

Scale-up of the Australian Fans in Training (Aussie-FIT) men's health behaviour change program: a protocol for a randomised controlled hybrid effectiveness-implementation trial.

INTRODUCTION: Improving physical activity (PA) and healthy eating is critical for primary and secondary prevention of cardiovascular disease (CVD). Behaviour change programmes delivered in sporting clubs can engage men in health behaviour change, but are rarely sustained or scaled-up post trial. Following the success of pilot studies of the Australian Fans in Training (Aussie-FIT) programme, a hybrid effectiveness-implementation trial protocol was developed. This protocol outlines methods to: (1) establish if Aussie-FIT is effective at supporting men with or at risk of CVD to sustain improvements in moderate-to-vigorous PA (primary outcome), diet and physical and psychological health and (2) examine the feasibility and utility of implementation strategies to support programme adoption, implementation and sustainment. METHODS AND ANALYSIS: A pragmatic multistate/territory hybrid type 2 effectiveness-implementation parallel group randomised controlled trial with a 6-month wait list control arm in Australia. 320 men aged 35-75 years with or at risk of CVD will be recruited. Aussie-FIT involves 12 weekly face-to-face sessions including coach-led interactive education workshops and PA delivered in Australian Football League (Western Australia, Northern Territory) and rugby (Queensland) sports club settings. Follow-up measures will be at 3 and 6 months (both groups) and at 12 months to assess maintenance (intervention group only). Implementation outcomes will be reported using the Reach, Effectiveness, Adoption, Implementation, Maintenance framework. ETHICS AND DISSEMINATION: This multisite study has been approved by the lead ethics committees in the lead site's jurisdiction, the South Metropolitan Health Service Human Research Ethics Committee (Reference RGS4254) and the West Australian Aboriginal Health Ethics Committee (HREC1221). Findings will be disseminated at academic conferences, peer-reviewed journals and via presentations and reports to stakeholders, including consumers. Findings will inform a blueprint to support the sustainment and scale-up of Aussie-FIT across diverse Australian settings and populations to benefit men's health. TRIAL REGISTRATION NUMBER: This trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12623000437662).

Associations of physical activity and quality of life in parapneumonic effusion patients.

Introduction: Little is known about activity behaviours and quality of life (QoL) of patients with parapneumonic pleural effusions (PPE) after hospital discharge. This study is a secondary analysis of a randomised trial (dexamethasone versus placebo) for hospitalised patients with PPE. We: 1) described the patients' activity behaviour patterns and QoL measured at discharge and at 30 days post-discharge; and 2) examined the association between activity behaviours and QoL scores. Methods: Activity behaviour (7-day accelerometry; Actigraph GT3X+) and QoL (Medical Outcomes Study Short-Form 36) were assessed. Repeated measures analysis of covariance controlling for baseline values and a series of linear regression models were undertaken. Results: 36 out of 53 eligible participants completed accelerometry assessments. Despite modest increases in light physical activity (+7.5%) and some domains of QoL (>2 points) from discharge to 30 days post-discharge, patients had persistently high levels of sedentary behaviour (>65% of waking wear time) and poor QoL (≤50 out of 100 points) irrespective of treatment group (p=0.135-0.903). Increasing moderate-to-vigorous physical activity was associated with higher scores on most QoL domains (p=0.006-0.037). Linear regression indicates that a clinically important difference of 5 points in physical composite QoL score can be achieved by reallocating 16.1 min·day-1 of sedentary time to moderate-to-vigorous physical activity. Conclusion: Patients with PPE had low levels of physical activity and QoL at discharge and 30 days post-discharge irrespective of treatment. Moderate-to-vigorous physical activity participation was associated with higher QoL scores. Increasing moderate-to-vigorous physical activity following discharge from the hospital may be associated with improvements in QoL.

Estimating sleep duration: performance of open-source processing of actigraphy compared to in-laboratory polysomnography in the community.

Comparisons of actigraphy findings between studies are challenging given differences between brand-specific algorithms. This issue may be minimized by using open-source algorithms. However, the accuracy of actigraphy-derived sleep parameters processed in open-source software needs to be assessed against polysomnography (PSG). Middle-aged adults from the Raine Study (n = 835; F 58%; Age 56.7 ± 5.6 years) completed one night of in-laboratory PSG and concurrent actigraphy (GT3X+ ActiGraph). Actigraphic measures of total sleep time (TST) were analyzed and processed using the open-source R-package GENEActiv and GENEA data in R (GGIR) with and without a sleep diary and additionally processed using proprietary software, ActiLife, for comparison. Bias and agreement (intraclass correlation coefficient) between actigraphy and PSG were examined. Common PSG and sleep health variables associated with the discrepancy between actigraphy, and PSG TST were examined using linear regression. Actigraphy, assessed in GGIR, with and without a sleep diary overestimated PSG TST by (mean ± SD) 31.0 ± 50.0 and 26.4 ± 69.0 minutes, respectively. This overestimation was greater (46.8 ± 50.4 minutes) when actigraphy was analyzed in ActiLife. Agreement between actigraphy and PSG TST was poor (ICC = 0.27-0.44) across all three methods of actigraphy analysis. Longer sleep onset latency and longer wakefulness after sleep onset were associated with overestimation of PSG TST. Open-source processing of actigraphy in a middle-aged community population, agreed poorly with PSG and, on average, overestimated TST. TST overestimation increased with increasing wakefulness overnight. Processing of actigraphy without a diary in GGIR was comparable to when a sleep diary was used and comparable to actigraphy processed with proprietary algorithms in ActiLife.

Physical Activity, Sedentary and Sleep Phenotypes in Women During the First Trimester of Pregnancy.

OBJECTIVES: Patterns of physical behaviors including physical activity, sedentary time, and sleep are unknown during pregnancy, but are likely to influence health outcomes. The purpose was to first identify "physical behavior phenotypes" from accelerometer-measured physical behaviors in pregnant women during the first trimester and secondly, to explore the associations between the identified phenotypes with demographic variables and body-mass-index (BMI). METHODS: Data were from the Glowing Study (gov ID: NCT01131117), collected between 2011 and 2017 with accelerometer-measured physical behaviors of women in their 12th week of pregnancy. Latent class analysis was used to identify patterns of total physical activity, sleep time, sedentary time, and variation in physical activity. Maternal Body-Mass-Index (BMI). BMI and sociodemographic characteristics were compared between physical behavior phenotypes. RESULTS: A total of 212 pregnant women were included in the study (mean age 30.2 years (range 22.1 to 42.4), mean days wear 4.3 (SD 0.7)). Three physical behavior phenotypes were identified from the four physical behavior constructs: low sedentary and stable activity (n = 136, 64%), variable activity (n = 39, 18%), high sedentary and low sleep (n = 37, 17%). BMI, race, and education were significantly different between the three phenotypes, with the low sedentary and stable activity phenotype having the lowest BMI and a higher percentage of white and college educated women. CONCLUSIONS FOR PRACTICE: Total physical activity and physical behavior phenotypes during the first trimester were associated with early-pregnancy BMI, race, and education. Future research should examine whether these physical behavior phenotypes are associated with maternal and child health outcomes.

Self-supervised learning of accelerometer data provides new insights for sleep and its association with mortality.

Background: Sleep is essential to life. Accurate measurement and classification of sleep/wake and sleep stages is important in clinical studies for sleep disorder diagnoses and in the interpretation of data from consumer devices for monitoring physical and mental well-being. Existing non-polysomnography sleep classification techniques mainly rely on heuristic methods developed in relatively small cohorts. Thus, we aimed to establish the accuracy of wrist-worn accelerometers for sleep stage classification and subsequently describe the association between sleep duration and efficiency (proportion of total time asleep when in bed) with mortality outcomes. Methods: We developed and validated a self-supervised deep neural network for sleep stage classification using concurrent laboratory-based polysomnography and accelerometry data from three countries (Australia, the UK, and the USA). The model was validated within-cohort using subject-wise five-fold cross-validation for sleep-wake classification and in a three-class setting for sleep stage classification wake, rapid-eye-movement sleep (REM), non-rapid-eye-movement sleep (NREM) and by external validation. We assessed the face validity of our model for population inference by applying the model to the UK Biobank with 100,000 participants, each of whom wore a wristband for up to seven days. The derived sleep parameters were used in a Cox regression model to study the association of sleep duration and sleep efficiency with all-cause mortality. Findings: After exclusion, 1,448 participant nights of data were used to train the sleep classifier. The difference between polysomnography and the model classifications on the external validation was 34.7 minutes (95% limits of agreement (LoA): -37.8 to 107.2 minutes) for total sleep duration, 2.6 minutes for REM duration (95% LoA: -68.4 to 73.4 minutes) and 32.1 minutes (95% LoA: -54.4 to 118.5 minutes) for NREM duration. The derived sleep architecture estimate in the UK Biobank sample showed good face validity. Among 66,214 UK Biobank participants, 1,642 mortality events were observed. Short sleepers (<6 hours) had a higher risk of mortality compared to participants with normal sleep duration (6 to 7.9 hours), regardless of whether they had low sleep efficiency (Hazard ratios (HRs): 1.69; 95% confidence intervals (CIs): 1.28 to 2.24 ) or high sleep efficiency (HRs: 1.42; 95% CIs: 1.14 to 1.77). Interpretation: Deep-learning-based sleep classification using accelerometers has a fair to moderate agreement with polysomnography. Our findings suggest that having short overnight sleep confers mortality risk irrespective of sleep continuity.

Childhood sleep health and epigenetic age acceleration in late adolescence: Cross-sectional and longitudinal analyses.

AIM: Investigate if childhood measures of sleep health are associated with epigenetic age acceleration in late adolescence. METHODS: Parent-reported sleep trajectories from age 5 to 17, self-reported sleep problems at age 17, and six measures of epigenetic age acceleration at age 17 were studied in 1192 young Australians from the Raine Study Gen2. RESULTS: There was no evidence for a relationship between the parent-reported sleep trajectories and epigenetic age acceleration (p ≥ 0.17). There was a positive cross-sectional relationship between self-reported sleep problem score and intrinsic epigenetic age acceleration at age 17 (b = 0.14, p = 0.04), which was attenuated after controlling for depressive symptom score at the same age (b = 0.08, p = 0.34). Follow-up analyses suggested this finding may represent greater overtiredness and intrinsic epigenetic age acceleration in adolescents with higher depressive symptoms. CONCLUSION: There was no evidence for a relationship between self- or parent-reported sleep health and epigenetic age acceleration in late adolescence after adjusting for depressive symptoms. Mental health should be considered as a potential confounding variable in future research on sleep and epigenetic age acceleration, particularly if subjective measures of sleep are used.

Device assessed activity behaviours in patients with indwelling pleural catheter: A sub-study of the Australasian Malignant PLeural Effusion (AMPLE)-2 randomized trial.

BACKGROUND AND OBJECTIVE: Device-assessed activity behaviours are a novel measure for comparing intervention outcomes in patients with malignant pleural effusion (MPE). Australasian Malignant PLeural Effusion (AMPLE)-2 was a multi-centre clinical trial where participants with MPE treated with an indwelling pleural catheter were randomized to daily (DD) or symptom-guided (SGD) drainage for 60-days. Our aim was to describe activity behaviour patterns in MPE patients, explore the impact of drainage regimen on activity behaviours and examine associations between activity behaviours and quality of life (QoL). METHODS: Following randomization to DD or SGD, participants enrolled at the lead site (Perth) completed accelerometry assessment. This was repeated monthly for 5-months. Activity behaviour outcomes were calculated as percent of daily waking-wear time and compared between groups (Mann-Whitney U test; Median [IQR]). Correlations between activity behaviour outcomes and QoL were examined. RESULTS: Forty-one (91%) participants provided ≥1 valid accelerometry assessment (DDn = 20, SGD n = 21). Participants spent a large proportion of waking hours sedentary (72%-74% across timepoints), and very little time in moderate-to-vigorous physical activity (<1% across timepoints). Compared to SGD group, DD group had a more favourable sedentary-to-light ratio in the week following randomization (2.4 [2.0-3.4] vs. 3.2 [2.4-6.1]; p = 0.047) and at 60-days (2.0 [1.9-2.9] vs. 2.9 [2.8-6.0]; p = 0.016). Sedentary-to-light ratio was correlated with multiple QoL domains at multiple timepoints. CONCLUSION: Patients with MPE are largely sedentary. Preliminary results suggest that even modest differences in activity behaviours favouring the DD group could be meaningful for this clinical population. Accelerometry reflects QoL and is a useful outcome measure in MPE populations.

Relationship between TV watching during childhood and adolescence and fitness in adulthood in the Raine Study cohort.

To investigate: (1) whether TV watching habits throughout childhood and adolescence, a proxy of sedentary behaviour, impacted cardiorespiratory fitness (CRF) in adulthood, and (2) whether any potential impact of TV watching in childhood and adolescence on CRF in adulthood was changed by adult physical activity (PA) levels. A longitudinal study with questionnaire data available regarding TV watching collected at ages 5, 8, 10, 14, 17 and 20 yrs, allowed trajectories of TV watching to be developed. At age 28 yrs, participants completed a V̇O2peak test and the International Physical Activity Questionnaire. General linear models tested for differences in CRF (time to exhaustion TTE and V̇O2peak mL·kg-1·min-1) between TV watching trajectories. The secondary analysis tested the potential effect current PA levels has on the relationship between TV trajectory and fitness. In total, 449 participants [male n = 255 (56.8%), 28.3 ± 0.5 yrs; female n = 194 (43.2%), 28.2 ± 0.4 yrs] were included in the study. Three distinct trajectories of TV watching were identified: High TV, Increasing TV and Low TV. CRF was lowest in the High TV watching trajectory and increased progressively from High to Increasing TV and Increasing to Low TV (all P < .05). Within each of the TV trajectories, those engaging in high levels of current PA had greater CRF than those engaging in low and moderate PA. TV watching in childhood and adolescence negatively impacts upon adult fitness at the age of 28 years. However, this negative impact of historical TV watching on CRF can largely be attenuated by engaging in higher levels of PA in adulthood.

Sedentary Behaviour, Physical Activity, and Their Associations with Health Outcomes at the Time of Diagnosis in People with Inoperable Lung Cancer.

This study aimed to examine sedentary behaviour (SB), physical activity (PA) and their associations with health-related measures at the time of diagnosis in people with inoperable lung cancer. People newly diagnosed with inoperable lung cancer were invited to participate in the study and asked to wear an accelerometer for seven consecutive days. Variables analysed included time spent in SB, light intensity PA (LIPA) and moderate-to-vigorous intensity PA (MVPA). Daily steps were also recorded. Data on symptoms, health-related quality of life (HRQoL), hand grip force, comorbidities and lung function were collected. Of the 120 patients referred to the study, 89 (74%) consented to participate, and SB/PA data were available for 79 (age 71 ± 11 years; 29 females). Participants spent 71% of their waking time in SB, 28% in LIPA and 1% in MVPA. Regression models demonstrated that increased SB was associated with more symptoms of fatigue and dyspnoea (p ≤ 0.02 for both), poorer HRQoL (general health and physical component score; p ≤ 0.02 for all) and lower hand grip force. For PA variables, higher daily step count was associated with better scores in all health-related measures (p < 0.05 for all). LIPA was associated with more health-related outcomes than MVPA. These findings may guide future interventions in this population.

Demographic and psychosocial correlates of measurement error and reactivity bias in a four-day image-based mobile food record among adults with overweight and obesity.

Improving dietary reporting among people living with obesity is challenging as many factors influence reporting accuracy. Reactive reporting may occur in response to dietary recording but little is known about how image-based methods influence this process. Using a 4-day image-based mobile food record (mFRTM), this study aimed to identify demographic and psychosocial correlates of measurement error and reactivity bias, among adults with BMI 25-40kg/m2. Participants (n=155, aged 18-65y) completed psychosocial questionnaires, and kept a 4-day mFRTM. Energy expenditure (EE) was estimated using ≥4 days of hip-worn accelerometer data, and energy intake (EI) was measured using mFRTM. Energy intake: energy expenditure ratios were calculated, and participants in the highest tertile were considered to have Plausible Intakes. Negative changes in EI according to regression slopes indicated Reactive Reporting. Mean EI was 72% (SD=21) of estimated EE. Among participants with Plausible Intakes, mean EI was 96% (SD=13) of estimated EE. Higher BMI (OR 0.81, 95%CI 0.72-0.92) and greater need for social approval (OR 0.31, 95% CI 0.10-0.96), were associated with lower likelihood of Plausible Intakes. Estimated EI decreased by 3% per day of recording (IQR -14%,6%) among all participants. The EI of Reactive Reporters (n=52) decreased by 17%/day (IQR -23%,-13%). A history of weight loss (>10kg) (OR 3.4, 95% CI 1.5-7.8), and higher percentage of daily energy from protein (OR 1.1, 95%CI 1.0-1.2) were associated with greater odds of Reactive Reporting. Identification of reactivity to measurement, as well as Plausible Intakes, is recommended in community-dwelling studies to highlight and address sources of bias.

Balance on the Brain: a randomised controlled trial evaluating the effect of a multimodal exercise programme on physical performance, falls, quality of life and cognition for people with mild cognitive impairment-study protocol.

INTRODUCTION: Exercise and physical activity have been shown to improve cognition for people living with mild cognitive impairment (MCI). There is strong evidence for the benefits of aerobic exercise and medium evidence for participating in regular strength training for people with MCI. However, people living with MCI fall two times as often as those without cognitive impairment and the evidence is currently unknown as to whether balance training for people with MCI is beneficial, as has been demonstrated for older people without cognitive impairment. The aim of this study is to determine whether a balance-focused multimodal exercise intervention improves balance and reduces falls for people with MCI, compared with a control group receiving usual care. METHODS AND ANALYSIS: This single blind randomised controlled trial (Balance on the Brain) will be offered to 396 people with MCI living in the community. The multimodal exercise intervention consists of two balance programmes and a walking programme to be delivered by physiotherapists over a 6-month intervention period. All participants will be followed up over 12 months (for the intervention group, this involves 6-month intervention and 6-month maintenance). The primary outcomes are (1) balance performance and (2) rate of falls. Physical performance, levels of physical activity and sedentary behaviour, quality of life and cognition are secondary outcomes. A health economic analysis will be undertaken to evaluate the cost-effectiveness of the intervention compared with usual care. ETHICS AND DISSEMINATION: Ethics approval has been received from the South Metropolitan Health Service Human Research Ethics Committee (HREC), Curtin University HREC and the Western Australia Department of Health HREC; and approval has been received to obtain data for health costings from Services Australia. The results will be disseminated through peer-review publications, conference presentations and online platforms. TRIAL REGISTRATION NUMBER: ACTRN12620001037998; Australian New Zealand Clinical Trials Registry (ANZCTR).

Changes in body composition in patients with malignant pleural mesothelioma and the relationship with activity levels and dietary intake.

BACKGROUND: Skeletal muscle loss is common in advanced cancer and is associated with negative outcomes. In malignant pleural mesothelioma (MPM), no study has reported body composition changes or factors associated with these changes. This study aimed to describe changes in body composition over time and its relationship with activity levels, dietary intake and survival. METHODS: The study was a secondary analysis of data collected from a longitudinal observational study of patients with MPM. Participants completed 3-month assessments for up to 18 months. Participants with two dual-energy x-ray absorptiometry (DXA) scans were included. Changes in appendicular skeletal muscle mass (ASM) and total fat mass were used to categorise participants into phenotypes. Activity levels were measured with an ActiGraph GT3X+ accelerometer and energy and protein intake was measured with a 3-day food record and 24-h recall. RESULTS: Eighteen participants were included (89% men, mean age 68.9 ± 7.1 years). Median time between DXA was 91 [IQR 84-118] days. Compared to participants with ASM maintenance (n = 9), fewer participants with ASM loss (n = 9) survived ≥12 months from follow-up (p = 0.002). Participants with ASM loss increased sedentary time (p = 0.028) and decreased light activity (p = 0.028) and step count (p = 0.008). Activity levels did not change in participants with ASM maintenance (p > 0.05). Energy and protein intake did not change in either group (p > 0.05). CONCLUSIONS: Muscle loss was associated with poorer survival and decreased activity levels. Interventions that improve physical activity or muscle mass could benefit patients with MPM.