Deep learning of movement behavior profiles and their association with markers of cardiometabolic health.

BACKGROUND: Traditionally, existing studies assessing the health associations of accelerometer-measured movement behaviors have been performed with few averaged values, mainly representing the duration of physical activities and sedentary behaviors. Such averaged values cannot naturally capture the complex interplay between the duration, timing, and patterns of accumulation of movement behaviors, that altogether may be codependently related to health outcomes in adults. In this study, we introduce a novel approach to visually represent recorded movement behaviors as images using original accelerometer outputs. Subsequently, we utilize these images for cluster analysis employing deep convolutional autoencoders. METHODS: Our method involves converting minute-by-minute accelerometer outputs (activity counts) into a 2D image format, capturing the entire spectrum of movement behaviors performed by each participant. By utilizing convolutional autoencoders, we enable the learning of these image-based representations. Subsequently, we apply the K-means algorithm to cluster these learned representations. We used data from 1812 adult (20-65 years) participants in the National Health and Nutrition Examination Survey (NHANES, 2003-2006 cycles) study who worn a hip-worn accelerometer for 7 seven consecutive days and provided valid accelerometer data. RESULTS: Deep convolutional autoencoders were able to learn the image representation, encompassing the entire spectrum of movement behaviors. The images were encoded into 32 latent variables, and cluster analysis based on these learned representations for the movement behavior images resulted in the identification of four distinct movement behavior profiles characterized by varying levels, timing, and patterns of accumulation of movement behaviors. After adjusting for potential covariates, the movement behavior profile characterized as "Early-morning movers" and the profile characterized as "Highest activity" both had lower levels of insulin (P < 0.01 for both), triglycerides (P < 0.05 and P < 0.01, respectively), HOMA-IR (P < 0.01 for both), and plasma glucose (P < 0.05 and P < 0.1, respectively) compared to the "Lowest activity" profile. No significant differences were observed for the "Least sedentary movers" profile compared to the "Lowest activity" profile. CONCLUSIONS: Deep learning of movement behavior profiles revealed that, in addition to duration and patterns of movement behaviors, the timing of physical activity may also be crucial for gaining additional health benefits.

Arterial stiffness and the reallocation of time between device-measured 24-hour movement behaviours: A compositional data analysis.

BACKGROUND AND AIMS: Arterial stiffness predicts cardiovascular morbidity and mortality. We aimed to quantify the differences in arterial stiffness associated with reallocating time between 24-h movement behaviours. METHODS: This observational cross-sectional study included Luxembourg residents aged 25-79y who each provided ≥4 valid days of triaxial accelerometry (n = 1001). Covariable adjusted compositional isotemporal substitution models were used to examine if theoretical reallocations of time between device-measured sedentariness, the sleep period, light physical activity (PA), and moderate-to-vigorous PA (MVPA) were associated with the percentage difference in carotid-femoral pulse wave velocity (cfPWV). We further investigated if replacing sedentary time accumulated in prolonged (≥30 min) with non-prolonged (<30 min) bouts was associated with arterial stiffness. The results are presented as 30 min time exchanges (ß (95% confidence interval)). RESULTS: Beneficial associations with lower cfPWV were observed when reallocating time to MVPA from the sleep period (-1.38 (-2.63 to -0.12) %), sedentary time (-1.70 (-2.76 to -0.62) %), and light PA (-2.51 (-4.55 to -0.43) %), respectively. Larger associations in the opposite direction were observed when reallocating MVPA to the same behaviours (for example, replacing MVPA with sedentary time: 2.50 (0.85-4.18) %). Replacing prolonged with non-prolonged sedentary time was not associated with cfPWV (-0.27 (-0.86 to 0.32) %). In short sleepers, reallocating sedentary time to the sleep period was favourable (-1.96 (-3.74 to -0.15) %). CONCLUSIONS: Increasing or at least maintaining MVPA appears to be important for arterial health in adults. Extending sleep in habitually short sleepers, specifically by redistributing sedentary time, may also be important.

Sociodemographic, temporal and bedtime routine correlates of sleep timing and duration in South Asian and white children: A Born in Bradford study.

Objective: The study aimed to examine sociodemographic, temporal and bedtime routine correlates of parent-reported sleep duration and timing in a biethnic sample of 18 month and 36 month old children from a disadvantaged location. Methods: Between October 2010 and September 2012, parents completed a bespoke three day sleep diary when their child was approximately 18 months (n = 276) and 36 months of age (n = 262) (45.1% South Asian; 54.9% white). Parents reported their child's overnight sleep duration (h/day), the time their child fell asleep, their wake time and their child's bedtime and napping routines. Data were available at both time points for 135 children. Results: In line with previous literature, South Asian children had shorter overnight sleep duration and later sleep and wake times than white children. In both ethnic groups, children slept and woke up later on weekends, and children went to bed earlier and slept longer in winter. In white children only, napping duration was associated with overnight sleep period. No significant associations were found between napping frequency and overnight sleep duration. Based on parent-reported data, children who consistently adhered to regular bedtimes and had set times for sleeping tended to go to sleep earlier, wake earlier and have longer overnight sleep. Conclusions: The data showed parent-reported variation in sleep patterns between two ethnic groups within a single geographical and deprived area. It is important that researchers, clinicians and early years workers are considerate of cultural norms in sleep practices.

Substituting device-measured sedentary time with alternative 24-hour movement behaviours: compositional associations with adiposity and cardiometabolic risk in the ORISCAV-LUX 2 study.

BACKGROUND: There is a considerable burden of sedentary time in European adults. We aimed to quantify the differences in adiposity and cardiometabolic health associated with theoretically exchanging sedentary time for alternative 24 h movement behaviours. METHODS: This observational cross-sectional study included Luxembourg residents aged 18-79 years who each provided ≥ 4 valid days of triaxial accelerometry (n = 1046). Covariable adjusted compositional isotemporal substitution models were used to examine if statistically replacing device-measured sedentary time with more time in the sleep period, light physical activity (PA), or moderate-to-vigorous PA (MVPA) was associated with adiposity and cardiometabolic health markers. We further investigated the cardiometabolic properties of replacing sedentary time which was accumulated in prolonged (≥ 30 min) with non-prolonged (< 30 min) bouts. RESULTS: Replacing sedentary time with MVPA was favourably associated with adiposity, high-density lipoprotein cholesterol, fasting glucose, insulin, and clustered cardiometabolic risk. Substituting sedentary time with light PA was associated with lower total body fat, fasting insulin, and was the only time-exchange to predict lower triglycerides and a lower apolipoprotein B/A1 ratio. Exchanging sedentary time with more time in the sleep period was associated with lower fasting insulin, and with lower adiposity in short sleepers. There was no significant evidence that replacing prolonged with non-prolonged sedentary time was related to outcomes. CONCLUSIONS: Artificial time-use substitutions indicate that replacing sedentary time with MVPA is beneficially associated with the widest range of cardiometabolic risk factors. Light PA confers some additional and unique metabolic benefit. Extending sleep, by substituting sedentary time with more time in the sleep period, may lower obesity risk in short sleepers.

Device-measured physical activity and sedentary time in a national sample of Luxembourg residents: the ORISCAV-LUX 2 study.

BACKGROUND: Existing information about population physical activity (PA) levels and sedentary time in Luxembourg are based on self-reported data. METHODS: This observational study included Luxembourg residents aged 18-79y who each provided ≥4 valid days of triaxial accelerometry in 2016-18 (n=1122). Compliance with the current international PA guideline (≥150 min moderate-to-vigorous PA (MVPA) per week, irrespective of bout length) was quantified and variability in average 24h acceleration (indicative of PA volume), awake-time PA levels, sedentary time and accumulation pattern were analysed by linear regression. Data were weighted to be nationally representative. RESULTS: Participants spent 51% of daily time sedentary (mean (95% confidence interval (CI)): 12.1 (12.0 to 12.2) h/day), 11% in light PA (2.7 (2.6 to 2.8) h/day), 6% in MVPA (1.5 (1.4 to 1.5) h/day), and remaining time asleep (7.7 (7.6 to 7.7) h/day). Adherence to the PA guideline was high (98.1%). Average 24h acceleration and light PA were higher in women than men, but men achieved higher average accelerations across the most active periods of the day. Women performed less sedentary time and shorter sedentary bouts. Older participants (aged ≥55y) registered a lower average 24h acceleration and engaged in less MVPA, more sedentary time and longer sedentary bouts. Average 24h acceleration was higher in participants of lower educational attainment, who also performed less sedentary time, shorter bouts, and fewer bouts of prolonged sedentariness. Average 24h acceleration and levels of PA were higher in participants with standing and manual occupations than a sedentary work type, but manual workers registered lower average accelerations across the most active periods of the day. Standing and manual workers accumulated less sedentary time and fewer bouts of prolonged sedentariness than sedentary workers. Active commuting to work was associated with higher average 24h acceleration and MVPA, both of which were lower in participants of poorer self-rated health and higher weight status. Obesity was associated with less light PA, more sedentary time and longer sedentary bouts. CONCLUSIONS: Adherence to recommended PA is high in Luxembourg, but half of daily time is spent sedentary. Specific population subgroups will benefit from targeted efforts to replace sedentary time with PA.

Associations Between Wearable-Specific Indicators of Physical Activity Behaviour and Insulin Sensitivity and Glycated Haemoglobin in the General Population: Results from the ORISCAV-LUX 2 Study.

BACKGROUND: Parameters derived from an acceleration signal, such as the time accumulated in sedentary behaviour or moderate to vigorous physical activity (MVPA), may not be sufficient to describe physical activity (PA) which is a complex behaviour. Incorporating more advanced wearable-specific indicators of PA behaviour (WIPAB) may be useful when characterising PA profiles and investigating associations with health. We investigated the associations of novel objective measures of PA behaviour with glycated haemoglobin (HbA1c) and insulin sensitivity (Quicki index). METHODS: This observational study included 1026 adults (55% women) aged 18-79y who were recruited from the general population in Luxembourg. Participants provided ≥ 4 valid days of triaxial accelerometry data which was used to derive WIPAB variables related to the activity intensity, accumulation pattern and the temporal correlation and regularity of the acceleration time series. RESULTS: Adjusted general linear models showed that more time spent in MVPA and a higher average acceleration were both associated with a higher insulin sensitivity. More time accumulated in sedentary behaviour was associated with lower insulin sensitivity. With regard to WIPAB variables, parameters that were indicative of higher PA intensity, including a shallower intensity gradient and higher average accelerations registered during the most active 8 h and 15 min of the day, were associated with higher insulin sensitivity. Results for the power law exponent alpha, and the proportion of daily time accumulated in sedentary bouts > 60 min, indicated that activity which was characterised by long sedentary bouts was associated with lower insulin sensitivity. A greater proportion of time spent in MVPA bouts > 10 min was associated with higher insulin sensitivity. A higher scaling exponent alpha at small time scales (< 90 min), which shows greater correlation in the acceleration time series over short durations, was associated with higher insulin sensitivity. When measured over the entirety of the time series, metrics that reflected a more complex, irregular and unpredictable activity profile, such as the sample entropy, were associated with lower HbA1c levels and higher insulin sensitivity. CONCLUSION: Our investigation of novel WIPAB variables shows that parameters related to activity intensity, accumulation pattern, temporal correlation and regularity are associated with insulin sensitivity in an adult general population.

Effect of a 16-week multi-level classroom standing desk intervention on cognitive performance and academic achievement in adolescents.

The replacement of traditional classroom desks for active-permissive desks has been tested to reduce sitting time during classes. However, their impact on other domains is still unclear. We aimed to verify the potential effects of a classroom standing desk intervention on cognitive function and academic achievement in 6th-grade students. This was a controlled trial conducted with two classes [intervention (n = 22) and control (n = 27)] from a public school in Lisbon, Portugal. The intervention was carried out for 16 weeks and consisted of multi-level actions (students, parents, and teachers) centered on the implementation of standing desks in the intervention classroom. The control group had traditional classes with no use of standing desks or any other interference/action from the research team. Pre- and post-assessments of executive functions (attention, inhibitory function, memory, and fluid intelligence) and academic achievement were obtained. No differences between groups were found at baseline. Both groups improved (time effect) academic achievement (p < 0.001), memory span (p < 0.001), and inhibitory function (p = 0.008). Group versus time interactions were observed regarding operational memory (intervention: + 18.0% and control: + 41.6%; p = 0.039) and non-verbal fluid intelligence (intervention: - 14.0% and control: + 3.9%; p = 0.017). We concluded that a 16-week classroom standing desk intervention did not improve cognitive performance or academic achievement more than the traditional sitting classes.Trial registration: ClinicalTrials.gov Identifier (NCT03137836) (date of first registration: 03/05/2017).

Associations between insomnia and pregnancy and perinatal outcomes: Evidence from mendelian randomization and multivariable regression analyses.

BACKGROUND: Insomnia is common and associated with adverse pregnancy and perinatal outcomes in observational studies. However, those associations could be vulnerable to residual confounding or reverse causality. Our aim was to estimate the association of insomnia with stillbirth, miscarriage, gestational diabetes (GD), hypertensive disorders of pregnancy (HDP), perinatal depression, preterm birth (PTB), and low/high offspring birthweight (LBW/HBW). METHODS AND FINDINGS: We used 2-sample mendelian randomization (MR) with 81 single-nucleotide polymorphisms (SNPs) instrumenting for a lifelong predisposition to insomnia. Our outcomes included ever experiencing stillbirth, ever experiencing miscarriage, GD, HDP, perinatal depression, PTB (gestational age <37 completed weeks), LBW (<2,500 grams), and HBW (>4,500 grams). We used data from women of European descent (N = 356,069, mean ages at delivery 25.5 to 30.0 years) from UK Biobank (UKB), FinnGen, Avon Longitudinal Study of Parents and Children (ALSPAC), Born in Bradford (BiB), and the Norwegian Mother, Father and Child Cohort (MoBa). Main MR analyses used inverse variance weighting (IVW), with weighted median and MR-Egger as sensitivity analyses. We compared MR estimates with multivariable regression of insomnia in pregnancy on outcomes in ALSPAC (N = 11,745). IVW showed evidence of an association of genetic susceptibility to insomnia with miscarriage (odds ratio (OR): 1.60, 95% confidence interval (CI): 1.18, 2.17, p = 0.002), perinatal depression (OR 3.56, 95% CI: 1.49, 8.54, p = 0.004), and LBW (OR 3.17, 95% CI: 1.69, 5.96, p < 0.001). IVW results did not support associations of insomnia with stillbirth, GD, HDP, PTB, and HBW, with wide CIs including the null. Associations of genetic susceptibility to insomnia with miscarriage, perinatal depression, and LBW were not observed in weighted median or MR-Egger analyses. Results from these sensitivity analyses were directionally consistent with IVW results for all outcomes, with the exception of GD, perinatal depression, and PTB in MR-Egger. Multivariable regression showed associations of insomnia at 18 weeks of gestation with perinatal depression (OR 2.96, 95% CI: 2.42, 3.63, p < 0.001), but not with LBW (OR 0.92, 95% CI: 0.69, 1.24, p = 0.60). Multivariable regression with miscarriage and stillbirth was not possible due to small numbers in index pregnancies. Key limitations are potential horizontal pleiotropy (particularly for perinatal depression) and low statistical power in MR, and residual confounding in multivariable regression. CONCLUSIONS: In this study, we observed some evidence in support of a possible causal relationship between genetically predicted insomnia and miscarriage, perinatal depression, and LBW. Our study also found observational evidence in support of an association between insomnia in pregnancy and perinatal depression, with no clear multivariable evidence of an association with LBW. Our findings highlight the importance of healthy sleep in women of reproductive age, though replication in larger studies, including with genetic instruments specific to insomnia in pregnancy are important.

Independent associations of sleep timing, duration and quality with adiposity and weight status in a national sample of adolescents: The UK Millennium Cohort Study.

Short sleep appears to elevate obesity risk in youth; however, sleep is a multidimensional construct, and few studies have investigated parameters beyond duration. The objective of this study was to investigate if sleep onset time, duration, latency and night waking frequency are independently associated with adiposity and weight status in UK adolescents. This was a cross-sectional observational study of 10,619, 13-15 years olds. Adjusted linear and logistic regressions were used to investigate associations of self-reported sleep characteristics with adiposity markers (body mass index z-score and percent body fat) and weight status. Compared with a sleep onset before 10pm, later sleep timing was associated with higher adiposity and higher likelihood of overweight and obesity in boys (after midnight, odds ratio [95% confidence interval]: 1.76 [1.19-2.60]) and girls (between 11pm and 11:59pm: 1.36 [1.17-1.65]). Sleeping ≤ 8 hr, compared with > 9-10 hr, was associated with higher odds of overweight and obesity in both sexes (boys: 1.80 [1.38-2.35]; girls: 1.38 [1.06-1.79]), and so too was sleeping > 10 hr in girls (1.31 [1.06-1.62]), indicating evidence for a U-shaped association. Also in girls, compared to a sleep latency of 16-30 min, sleep latencies ≥ 46 min were associated with higher adiposity (46-60 min, beta coefficient [95% confidence interval], percent body fat: 1.47 [0.57-2.36]) and higher likelihood of overweight and obesity (46-60 min: 1.39 [1.05-1.83]), and often as opposed to never waking in the night was associated with higher adiposity (body mass index z-score: 0.24 [0.08-0.41]; percent body fat: 1.44 [0.44-2.44]). Sleep duration and timing in both sexes, and sleep quality in girls, appear to be independently associated with adiposity and weight status in adolescence, and may be important targets for obesity prevention.

Cross-sectional and prospective associations of sleep duration and bedtimes with adiposity and obesity risk in 15 810 youth from 11 international cohorts.

OBJECTIVES: To investigate associations of bedtimes and sleep durations with adiposity levels in children and adolescents. METHODS: Individual data were pooled for 12 247 children (5819 with follow-up adiposity at 2.3 ± 1.4 years post-baseline) and 3563 adolescents from 11 international studies. Associations between questionnaire-based sleep durations, bedtimes and four groups of combined bedtimes and sleep lengths (later-shorter [reference]/earlier-shorter/later-longer/earlier-longer) with measured adiposity (body mass index [BMI] and waist circumference z-scores) and weight status, were investigated. RESULTS: In children, longer sleep durations were consistently associated with lower adiposity markers, and earlier bedtimes were related to lower BMI z-score. Compared to sleeping <10 h, longer baseline sleep duration favourably predicted Δwaist z-score in girls (≥10 and <11 h (ß-coefficient (95% confidence interval [CI])): -0.06 (-0.12 to -0.01)) and boys (≥11 h: -0.10 [-0.18 to -0.01]). Combined groups that were defined by longer sleep (later-longer and earlier-longer sleep patterns) were associated with lower adiposity, and later-longer sleep favourably predicted Δwaist z-score in girls (-0.09 [-0.15 to -0.02]). In adolescents, longer sleep durations and earlier bedtimes were associated with lower BMI z-score in the whole sample, and also with lower waist z-score in boys. Combined groups that were characterized by earlier bedtimes were associated with the same outcomes. For example, earlier-shorter (-0.22 (-0.43 to -0.01) and earlier-longer (-0.16 (-0.25 to -0.06) sleep were both associated with lower BMI z-score. CONCLUSIONS: If the associations are causal, longer sleep duration and earlier bedtimes should be targeted for obesity prevention, emphasizing longer sleep for children and earlier bedtimes for adolescents.

Physical activity can attenuate, but not eliminate, the negative relationships of high TV viewing with some chronic diseases: findings from a cohort of 60 202 Brazilian adults.

BACKGROUND: This study examined the joint associations of leisure time physical activity and television (TV) viewing time with the prevalence of chronic diseases among Brazilian adults. METHODS: Data from the Brazilian Health Survey, a nationally representative survey conducted in 2013 (n = 60 202; ≥18 years), were used. Time spent in TV viewing and leisure physical activity, physician diagnoses of diabetes, hypertension and heart disease and information on co-variables (chronological age, education, ethnicity, candies/sweets consumption, sodium intake and tobacco smoking) were collected via interview. Descriptive statistics (mean and 95% confidence interval) and logistic regression models were used for etiological analyses. RESULTS: Physical activity attenuated but did not eliminate the risk associated with high TV viewing for at least one chronic disease in the general population [odds ratio [OR]: 1.29 (1.11-1.50)] and among women [OR: 1.31 (1.09-1.60)], adults [OR: 1.24 (1.05-1.46)] and older adults [OR: 1.63 (1.05-2.53)]. On the other hand, physical activity eliminated the risk associated with high TV viewing for at least one chronic disease among men [OR: 1.24 (0.98-1.58)]. CONCLUSIONS: We conclude that physical activity can attenuate but not eliminate the negative effects of high TV viewing on chronic disease among subgroups of Brazilian adults.

Compositional Associations of Sleep and Activities within the 24-h Cycle with Cardiometabolic Health Markers in Adults.

PURPOSE: This study aimed to examine how compositions of 24-h time use and time reallocations between movement behaviors are associated with cardiometabolic health in a population-based sample of middle-age Finnish adults. METHODS: Participants were 3443 adults 46 yr of age from the Northern Finland Birth Cohort 1966 study. Participants wore a hip-worn accelerometer for 14 d from which time spent in sedentary behavior (SB), light-intensity physical activity (LPA), and moderate- to vigorous-intensity physical activity (MVPA) were determined. These data were combined with self-reported sleep to obtain the 24-h time-use composition. Cardiometabolic outcomes included adiposity markers, blood lipid levels, and markers of glucose control and insulin sensitivity. Multivariable-adjusted regression analysis, using a compositional data analysis approach based on isometric log-ratio transformation, was used to examine associations between movement behaviors with cardiometabolic outcomes. RESULTS: More daily time in MVPA and LPA, relative to other movement behaviors, was consistently favorably associated with all cardiometabolic outcomes. For example, relative to time spent in other behaviors, 30 min·d-1 more MVPA and LPA were both associated with lower 2-h post-glucose load insulin level (-11.8% and -2.7%, respectively). Relative to other movement behaviors, more daily time in SB was adversely associated with adiposity measures, lipid levels, and markers of insulin sensitivity, and more daily time asleep was adversely associated with adiposity measures, blood lipid, fasting plasma glucose, and 2-h insulin. For example, 60 min·d-1 more SB and sleep relative to the remaining behaviors were both associated with higher 2-h insulin (3.5% and 5.7%, respectively). CONCLUSIONS: Altering daily movement behavior compositions to incorporate more MVPA at the expense of any other movement behavior, or more LPA at the expense of SB or sleep, could help to improve cardiometabolic health in midadulthood.

Objectively-measured sedentary time and physical activity in a bi-ethnic sample of young children: variation by socio-demographic, temporal and perinatal factors.

BACKGROUND: Evidence suggests that South Asian school-aged children and adults are less active compared to the white British population. It is unknown if this generalises to young children. We aimed to describe variability in levels of physical activity and sedentary time in a bi-ethnic sample of young children from a deprived location. METHODS: This observational study included 202 South Asian and 140 white British children aged 1.5 to 5y, who provided 3181 valid days of triaxial accelerometry (Actigraph GT3X+). Variability in sedentary time and physical activity levels were analysed by linear multilevel modelling. Logistic multilevel regression was used to identify factors associated with physical inactivity (failing to perform ≥180 min of total physical activity including ≥60 min moderate-to-vigorous physical activity (MVPA) per day). RESULTS: There were no significant ethnic differences in the overall levels of behaviours; South Asian and white British children spent half of daily time sedentary, just over 40% in light physical activity, and the remaining 7.5 to 8% of time in MVPA. Sedentary time was lower and physical activity levels were higher in older children, and levels of MVPA and vector magnitude counts per minute (CPM) were higher on weekends compared to weekdays. In South Asian children, sedentary time was lower on weekends. Sedentary time was lower and physical activity levels were higher in spring compared to winter in white British children, and in all seasons compared to winter in South Asian children. South Asian children born at high birth weight performed more MVPA, and in both ethnicities there was some evidence that children with older mothers were more sedentary and less active. Sedentary time was higher and light physical activity was lower in South Asian children in the highest compared to the lowest income families. South Asian girls performed less MVPA, registered fewer vector magnitude CPM, and were 3.5 times more likely to be physically inactive than South Asian boys. CONCLUSIONS: Sedentary time and physical activity levels vary by socio-demographic, temporal and perinatal characteristics in young children from a deprived location. South Asian girls have the most to gain from efforts to increase physical activity levels. TRIAL REGISTRATION: The Pre-schoolers in the Playground (PiP) pilot randomized controlled trial is registered with the ISRCTN (ISRCTN54165860; http://www.isrctn.com).

Maternal Physical Activity and Neonatal Cord Blood Lipid Levels: Findings From a Prospective Pregnancy Cohort.

BACKGROUND: Physical activity performed while pregnant is beneficially associated with maternal cardiovascular health. It is unknown if benefits extend to neonatal cardiovascular health. This study investigated associations of maternal physical activity with neonatal cord blood lipid and lipoprotein concentrations. METHODS: Cord blood lipids were measured at birth in a pseudorandomly selected subgroup of Born in Bradford birth cohort participants (N = 1634). Pregnant women were grouped into 4 activity categories (inactive/somewhat active/moderately active/active) based on their self-reported physical activity at 26- to 28-weeks gestation. Regression was used to calculate adjusted mean differences in neonatal cord blood lipid concentrations among the 4 groups of physical activity. RESULTS: Maternal physical activity was associated with higher neonatal cord blood high-density lipoprotein cholesterol. Cord blood high-density lipoprotein cholesterol was higher in neonates of women who were somewhat and moderately active compared with neonates of women who were inactive. There were no associations of pregnancy physical activity with triglycerides, low-density lipoprotein, very low-density lipoprotein cholesterol, or adiponectin levels. CONCLUSIONS: Maternal physical activity is favorably associated with neonatal cord blood high-density lipoprotein cholesterol levels. This novel beneficial finding highlights the potential for physical activity in pregnancy to aid the early prevention of cardiovascular disease.

Associations of Pregnancy Physical Activity with Maternal Cardiometabolic Health, Neonatal Delivery Outcomes and Body Composition in a Biethnic Cohort of 7305 Mother-Child Pairs: The Born in Bradford Study.

OBJECTIVE: Physical activity is advocated for a range of benefits to the uncomplicated pregnancy. We investigated associations of mid-pregnancy physical activity with maternal and neonatal health in white British and Pakistani-origin women from a deprived urban setting. METHODS: The study was performed in 6921 pregnant women (53% Pakistani-origin) who contributed data for 7305 singleton births. At 26-28 weeks gestation, women were grouped into four activity levels (inactive/somewhat active/moderately active/active) based on their self-reported physical activity. Linear regression with robust standard errors was used to calculate adjusted mean differences in health markers between the four groups of physical activity (reference group: inactive). RESULTS: Three-quarters (74%) of Pakistani-origin women and 39% of white British women were inactive. Trend-tests revealed that more active white British women tended to be less adipose, had lower fasting and postload glucose levels, lower triglyceride concentrations, and their babies were less adipose (smaller triceps and subscapular skinfolds) than less active white British women. Somewhat active Pakistani-origin women exhibited lower triglyceride concentrations and systolic blood pressure, higher high-density lipoprotein cholesterol levels, and their babies were less adipose (smaller mid-upper arm and abdominal circumferences; lower cord-blood leptin concentration) compared to inactive Pakistani-origin women. No associations were observed for gestational age or birth weight. CONCLUSIONS: Physical activity performed mid-pregnancy was beneficially associated with maternal cardiometabolic health and neonatal adiposity, without influencing gestational age or birth weight. Associations were dose-dependent in white British women, and even a small amount of mid-pregnancy physical activity appeared to benefit some health markers in Pakistani-origin women.

Associations of sedentary behaviors and physical activity with social isolation in 100,839 school students: The Brazilian Scholar Health Survey.

OBJECTIVE: To examine the relationship between physical activity, sedentary behaviors, and social isolation in a representative sample of Brazilian adolescents. METHOD: Cross sectional analyses using data from the Brazilian Scholar Health Survey conducted in 2015. The sample included 100,839 adolescents (mean age: 14.3 y, 51.4% Female) from 3040 schools. Information about social isolation (number of close friends and perceived loneliness), physical activity (International Physical Activity Questionnaire) and sedentary behaviors (total sitting time and TV viewing) were self-reported. Chronological age, race and type of city (state capital or other) were co-variables. Logistic regression models were used to analyze the data (results are presented as odds ratios (OR) with 95% confidence intervals). RESULTS: Physical activity was associated with lower odds of both social isolation indicators in boys, and with lower likelihood of having few friends in girls. Greater sitting time was associated with higher likelihood of social isolation, as was low (<1 h/d) [boys: OR: 1.54 (95% CI: 1.33 to 1.77); girls: OR: 1.31 (95% CI: 1.17 to 1.48] and high TV viewing (≥8 h/d) [boys: OR: 1.75 (95% CI: 1.47 to 2.09)]; girls: OR: 1.58 (95% CI: 1.37 to 1.82)]. More than 300 min/week of physical activity was sufficient to eliminate the association of high TV viewing and high sitting time with markers of social isolation in boys. CONCLUSION: Physical activity is associated with a lower prevalence of social isolation, especially among boys. Both high and low amounts of TV viewing increase the likelihood of social isolation. Physical activity reduced the association between TV viewing and sitting with social isolation among boys.

Biocultural approach of the association between maturity and physical activity in youth / Abordagem biocultural da associação entre maturação e atividade física na juventude

Abstract Objective: To test the biocultural model through direct and indirect associations between biological maturation, adiposity, cardiorespiratory fitness, feelings of sadness, social relationships, and physical activity in adolescents. Methods: This was a cross-sectional study conducted with 1,152 Brazilian adolescents aged between 10 and 17 years. Somatic maturation was estimated through Mirwald's method (peak height velocity). Physical activity was assessed through Baecke questionnaire (occupational, leisure, and sport contexts). Body mass index, body fat (sum of skinfolds), cardiorespiratory fitness (20-m shuttle run test), self-perceptions of social relationship, and frequency of sadness feelings were obtained for statistical modeling. Results: Somatic maturation is directly related to sport practice and leisure time physical activity only among girls (β = 0.12, p < 0.05 and β = 0.09, respectively, p < 0.05). Moreover, biological (adiposity and cardiorespiratory fitness), psychological (sadness), and social (satisfaction with social relationships) variables mediated the association between maturity and physical activity in boys and for occupational physical activity in girls. In general, models presented good fit coefficients. Conclusion: Biocultural model presents good fit and emotional/biological factors mediate part of the relationship between somatic maturation and physical activity.

Resumo Objetivo: Testar o modelo biocultural por meio de associações diretas e indiretas entre maturação biológica, adiposidade, capacidade cardiorrespiratória, sentimentos de tristeza, relacionamentos sociais e atividade física em adolescentes. Métodos: Este foi um estudo transversal feito com 1.152 adolescentes brasileiros entre 10 e 17 anos. A maturação somática foi estimada por meio do método de Mirwald (pico da velocidade de crescimento). A atividade física foi avaliada por meio do questionário de Baecke (contextos ocupacional, lazer e prática de esportes). Foram obtidos o índice de massa corporal, gordura corporal (soma de dobras cutâneas), capacidade cardiorrespiratória (teste shuttle run de 20 metros), autopercepções de relação social e frequência de sensação de tristeza para modelagem estatística. Resultados: A maturação somática mostrou-se diretamente relacionada à prática de esportes e à atividade física de lazer somente entre meninas (β = 0,12, p < 0,05 e β = 0,09, respectivamente, p < 0,05). Ademais, as variáveis biológicas (adiposidade e aptidão cardiorrespiratória), psicológica (tristeza) e social (satisfação com os relacionamentos sociais) mediaram a associação entre maturação e atividade física em meninos e para atividade física ocupacional em meninas. Em geral, os modelos apresentaram bons coeficientes de ajuste. Conclusão: O modelo biocultural apresenta bom ajuste e fatores emocionais/biológicos mediam parte da relação entre maturação somática e atividade física.

Associations of TV Viewing Duration, Meals and Snacks Eaten When Watching TV, and a TV in the Bedroom with Child Adiposity.

OBJECTIVE: This study aimed to examine the associations of TV parameters with adiposity in early life. METHODS: Data were collected as part of the Born in Bradford (BiB) longitudinal birth cohort study. Child TV viewing duration was parent reported, and BMI, the sum of triceps and subscapular skinfolds, and waist circumference were measured at ~12, 18, 24, and 36 months of age in 1,338 children. Mixed effects models were used to quantify adjusted associations of TV viewing duration with adiposity markers, incorporating data from all time points. Linear regression was used to investigate differences in adiposity levels across frequencies of eating meals and snacks while watching TV at age ~24 months and between children who did and did not have a TV in their bedroom at age ~36 months. RESULTS: Every 1 h/d of TV viewing was associated with a 0.075-cm larger (95% CI: 0.0034-0.15) waist circumference, independent of covariates including sleep duration, dietary factors, and physical activity level. There was no evidence for any other associations. CONCLUSIONS: TV viewing duration is independently associated with abdominal adiposity in young children. Limiting TV viewing from an early age may be important for primary prevention of obesity.

TV Viewing in 60,202 Adults From the National Brazilian Health Survey: Prevalence, Correlates, and Associations With Chronic Diseases.

BACKGROUND: This study describes the levels and patterns of television (TV) viewing in Brazilian adults and investigates associations of TV viewing with hypertension, type 2 diabetes, and heart disease. METHODS: Data from the Brazilian Health Survey, a nationally representative survey that was conducted in 2013 (N = 60,202 men and women aged ≥18 y), were used. Information regarding TV viewing, physician diagnoses of type 2 diabetes, hypertension, and heart disease was collected via interview-administered questionnaire. Data on covariables (including chronological age, educational status, skin color, sodium consumption, sugar consumption, tobacco smoking, alcohol consumption, and leisure-time physical activity) were also self-reported. Logistic regression models and population attributable fractions were used for the etiological analyses. RESULTS: The prevalence (95% confidence interval) of >4 hours per day of TV viewing was 12.7% (12.0-13.4) in men and 17.5% (16.8-18.3) in women. Men and women being younger or older, moderately educated, living alone, smoking tobacco, and drinking alcohol were associated with higher reported TV viewing time. Odds ratios (95% confidence interval) revealed that >4 hours per day of TV viewing was associated with type 2 diabetes [male: 1.64 (1.23-2.17) and female: 1.33 (1.09-1.63)], hypertension [male: 1.36 (1.14-1.63) and female: 1.20 (1.05-1.37)], and heart disease [male: 1.96 (1.43-2.69) and female: 1.30 (1.00-1.68)]. Exceeding 4 hours per day of TV viewing was responsible for 6.8% of type 2 diabetes, 3.7% of hypertension, and 7.5% of heart disease cases. CONCLUSIONS: Independent of covariates, >4 hours per day of TV viewing was associated with type 2 diabetes, hypertension, and heart disease. High volumes of TV viewing are prevalent and appear to contribute to chronic disease burden.