Independent, Stratified, and Joint Associations of Sedentary Time and Physical Activity With Cardiovascular Disease: A Systematic Review.

BACKGROUND: Recent statistics highlight cardiovascular diseases (CVD) as a major global cause of death. This review examines the methodological approaches and the main results of independent, stratified, and joint association of sedentary time (ST) and physical activity (PA) on CVD outcomes. METHODS: We searched PubMed, Embase, Web of Science, and Scopus for prospective cohorts that examined the independent, stratified, or joint associations of ST and PA with CVD outcomes. Independent associations were defined as analyses mutually adjusted for PA and ST. Stratified associations were considered when there was a reference group in each stratum of PA or ST, and joint associations were defined by a single reference group for all other combined categories of ST and PA levels. RESULTS: Of 45 articles, 69% explored independent association of ST or PA on CVD outcomes, while 31% using a stratified/joint approach. Most studies used self-reports for ST and PA and focused on CVD mortality. Mutually adjusted analyses identified ST positively and PA inversely associated to CVD outcomes. Stratified studies showed higher ST's pronounced impact on CVD for lower PA levels. High PA mitigated but did not eliminate ST's negative impact. Joint analyses revealed highest CVD risk in those with both high ST and low PA, and elevated risk in various intermediate combinations. CONCLUSIONS: Employing independent, stratified, and joint association approaches can yield distinct and complementary public health messages aimed at promoting cardiovascular health. Recommendations should aim to not only to encourage boosting PA levels, but also, concurrently decrease ST.

Factors associated with handgrip strength across the life course: A systematic review.

BACKGROUND: Muscle strength is essential for healthy ageing. Handgrip strength (HGS) has been recommended by expert bodies as the preferred measure of muscle strength, in addition to being considered a strong predictor of overall health. Cross-sectional studies have shown several potential factors associated with HGS, but a systematic review of factors predicting HGS over time has not previously been conducted. The aim of this study is to systematically review the literature on the factors associated with adult HGS [at follow-up(s) or its rate of change] across the life course. METHODS: Searches were performed in MEDLINE via Ebsco, Embase and SPORTDiscus databases. Longitudinal studies assessing potential factors impacting adult HGS over time were included in the analyses. Based on previously established definitions of consistency of results, a semiquantitative analysis was conducted using the proportions of studies supporting correlations with HGS. RESULTS: A total of 117 articles were included in this review. Factors associated with HGS were grouped into 11 domains: demographic, socioeconomic, genetic, early life, body composition, health markers/biomarkers, health conditions, psychosocial, lifestyle, reproductive and environmental determinants. Overall, 103 factors were identified, of which 10 showed consistent associations with HGS over time (i.e., in at least four studies with ≥60% agreement in the direction of association). Factors associated with greater declines in HGS included increasing age, male sex, higher levels of inflammatory markers and the presence of cardiovascular diseases. Education level, medication use, and self-rated health were not associated with the rate of change in HGS. Increased birth weight was associated with a stronger HGS over time, whereas depressive symptoms were linked to a weaker HGS, and smoking habits showed null associations. CONCLUSIONS: Comparison between studies and estimation of effect sizes were limited due to the heterogeneity in methods. Although sex and age may be the main drivers of HGS decline, it is crucial to prioritize modifiable factors such as inflammation and cardiovascular diseases in health interventions to prevent greater losses. Interventions to improve birth weight and mental health are also likely to produce positive effects on muscle strength. Our results point to the complexity of processes involving muscle strength and suggest that the need to better understand the determinants of HGS remains.

Participation in Sports/Recreational Activities and the Occurrence of Psychological Distress in Mid-Aged Adults: Findings From the HABITAT Cohort Study.

OBJECTIVES: The aim of this study was to investigate prospective associations between participation in sports/recreational activities and the occurrence of moderate-to-severe psychological distress over 2 years in a sample of mid-aged Australians. METHODS: This prospective study used data from 6699 adults aged 40+ years, living in Brisbane in 2007, and surveyed in 2009, 2011 and 2013. Participants provided self-reported data on frequency of participation in each of 11 sports/recreational activities in past 12 months and completed the Kessler Psychological Distress 6-item Scale (K6). Generalized estimating equation (GEE) models with a 2-year lag were used to assess the associations of participation in sports/recreational activities in 2009 and 2011 with new cases of moderate-to-severe psychological distress (K6 score ≥ 5) in 2011 and 2013. RESULTS: From 2009 to 2013, 22.4% of participants without moderate-to-severe psychological distress at baseline (N = 4943) developed this outcome in at least one survey. Overall, there were no clear patterns of association between frequency of participation in sports and recreational activities and occurrence of moderate-to-severe psychological distress. In unadjusted models, weekly participation in some activities (e.g., tennis, golf, and exercise classes) was associated with reduced odds of moderate-to-severe psychological distress over the next 2 years, but these associations were attenuated in most adjusted models with sociodemographic, lifestyle, and health covariates. Participation in home-based exercise and running/jogging were associated with higher odds of psychological distress. CONCLUSION: Our findings do not provide strong evidence of beneficial associations of frequency of sport/recreational activities with psychological distress but show surprising negative associations of home-based exercise and running/jogging with occurrence of moderate-to-severe psychological distress over 2 years.

[Obesity sociodemographic and behavioral factors: a longitudinal study]. / Fatores sociodemográficos e comportamentais da obesidade: um estudo longitudinal.

This study aimed to investigate the association between sociodemographic and behavioral factors and obesity from 2014 to 2021 in adults in São Paulo city, Brazil. A prospective study was carried out with 1,241 adults aged 18 years or above who lived in São Paulo and participated in the São Paulo Health Survey cohort (ISA) - Physical Activity and Environment. The outcome was obesity (yes/no), classified by body mass index and specific cut-off points for each age group. The exposure variables included sex, age, education, skin color, marital status, regional health coordination, physical activity in the four domains, and sedentary behaviors. Multilevel logistic regression models were used for longitudinal analysis. This study found a significant increase (27.7%) in the prevalence of obesity (from 22.6% to 28.9%). People who practiced at least 150 minutes of leisure-time physical activity per week (OR = 0.44; 95%CI: 0.26; 0.76), between 10 and 150 minutes per week of commuting physical activity (OR = 0.49; 95%CI: 0.30; 0.80), and had no partner (OR = 0.47; 95%CI: 0.28; 0.78) were less likely to be obese. People aged from 40 to 59 years (OR = 5.00; 95%CI: 2.02; 12.38) and who were black (OR = 4.70; 95%CI: 1.85; 11.95) were more likely to be obese. This study found an increase in the prevalence of obesity during the studied period, with increased odds for middle-aged and black people and decreased odds for those without a partner and those who practice physical activities in their leisure and as a form of commuting. These results can contribute to support programs and policies to control obesity.

O objetivo foi investigar a associação entre fatores sociodemográficos e comportamentais e a ocorrência da obesidade entre 2014 e 2021 em adultos da cidade de São Paulo, Brasil. Realizou-se estudo prospectivo com 1.241 adultos paulistanos, com 18 anos ou mais, participantes da coorte Inquérito de Saúde de São Paulo (ISA) - Atividade Física e Ambiente. O desfecho foi obesidade (sim/não), classificada por meio do índice de massa corporal e com pontos de corte específicos para cada faixa etária. As variáveis de exposição foram: sexo, idade, escolaridade, cor da pele, estado marital, coordenadoria regional de saúde, atividade física nos quatro domínios e comportamentos sedentários. Foram utilizados modelos de regressão logística multinível para a análise longitudinal. Houve aumento significativo de 27,7% na prevalência de obesidade (de 22,6% para 28,9%). Pessoas que praticavam ao menos 150 minutos semanais de atividade física no lazer (OR = 0,44; IC95%: 0,26; 0,76), entre 10 e 150 minutos semanais de atividade física de deslocamento (OR = 0,49; IC95: 0,30; 0,80) e sem companheiro(a) (OR = 0,47; IC95%: 0,28; 0,78) tiveram menos chances de ter obesidade. Pessoas entre 40 e 59 anos (OR = 5,00; IC95%: 2,02; 12,38) e de cor de pele preta (OR = 4,70; IC95%: 1,85; 11,95) apresentaram maiores chances de ter obesidade. O estudo identificou um aumento na prevalência de obesidade durante o período, com aumento nas chances para pessoas de meia idade e cor da pele preta, e diminuição nas chances para pessoas que vivem sem companheiro(a) e para praticantes de atividades físicas no lazer e como forma de deslocamento. Esses resultados podem contribuir para dar suporte a programas e políticas para o controle da obesidade.

El objetivo fue investigar la asociación entre factores sociodemográficos y conductuales y la presencia de la obesidad entre 2014 y 2021 en adultos de la ciudad de São Paulo, Brasil. Se realizó un estudio prospectivo con 1.241 adultos paulistanos, con 18 años o más, participantes de la cohorte Encuesta de Salud de São Paulo (ISA) - Actividad Física y Ambiente. El resultado fue obesidad (sí/no), clasificada a través del índice de masa corporal y con puntos de corte específicos para cada grupo de edad. Las variables de exposición fueron: sexo, edad, escolaridad, color de la piel, estado civil, coordinación regional de salud, actividad física en los cuatro dominios y comportamientos sedentarios. Para los análisis longitudinales se utilizaron modelos de regresión logística multinivel. Hubo un aumento significativo del 27,7% en la prevalencia de la obesidad (del 22,6% al 28,9%). Las personas que practicaron al menos 150 minutos semanales de actividad física por ocio (OR = 0,44; IC95%: 0,26; 0,76), entre 10 y 150 minutos semanales de actividad física de desplazamiento (OR = 0,49; IC95%: 0,30; 0,80) y sin compañero(a) (OR = 0,47; IC95%: 0,28; 0,78) tuvieron menos probabilidades de tener obesidad. Las personas entre 40 y 59 años (OR = 5,00; IC95%: 2,02; 12,38) y de color de piel negra (OR = 4,70; IC95%: 1,85; 11,95) presentaron mayores probabilidades de tener obesidad. El estudio identificó un aumento en la prevalencia de la obesidad durante ese período, con un aumento en las posibilidades para las personas de mediana edad y color de la piel negra, y una disminución en las posibilidades para las personas que viven sin pareja y para las que realizan actividades físicas por ocio y como forma de desplazamiento. Estos resultados pueden contribuir a apoyar los programas y políticas para el control de la obesidad.

Ecological momentary assessment of physical activity and sedentary behaviour in shift workers and non-shift workers: Validation study.

This study examined the criterion validity of an ecological momentary assessment (EMA)-reported physical activity and sedentary time compared with accelerometry in shift workers and non-shift workers. Australian workers (n = 102) received prompts through a mobile EMA app and wore the Actigraph accelerometer on the right hip for 7-10 days. Participants received five EMA prompts per day at 3-hour intervals on their mobile phones. EMA prompts sent to shift workers (SW-T) were tailored according to their work schedule. Non-shift workers (NSW-S) received prompts at standardised times. To assess criterion validity, the association of EMA-reported activities and the Actigraph accelerometer activity counts and number of steps were used. Participants were 36 ± 11 years and 58% were female. On occasions where participants reported physical activity, acceleration counts per minute (CPM) and steps were significantly higher (ß = 1184 CPM, CI 95%: 1034, 1334; ß = 20.9 steps, CI 95%: 18.2, 23.6) than each of the other EMA activities. Acceleration counts and steps were lower when sitting was reported than when no sitting was reported by EMA. Our study showed that EMA-reported physical activity and sedentary time was significantly associated with accelerometer-derived data. Therefore, EMA can be considered to assess shift workers' movement-related behaviours with accelerometers to provide rich contextual data.

Trajectories of Physical Activity and Chronic Conditions Among Mid-Aged Women.

INTRODUCTION: Women's physical activity levels vary throughout adulthood. However, the associations between trajectories of physical activity and health outcomes have been little studied. The aim of this study was to examine the associations of physical activity trajectories with incident diabetes, hypertension, obesity, depression, and physical disability in mid-aged women. METHODS: Data were from the 1946-51 cohort of the Australian Longitudinal Study on Women's Health (n=11,611). Mailed surveys at 3-year intervals from 1998 (age 47-52) to 2019 (age 68-73) were used to collect data on physical activity and each outcome. The analyses were conducted in 2023/24. Physical activity trajectories from age 47-61 (2-4 time-points) were identified using group-based trajectory modeling. Cox regression models with time-varying covariates were used to examine the associations of physical activity trajectories with adverse health outcomes onset from ages 56-73 (2-5 time-points). RESULTS: Trajectories of physical activity were labeled as Low (59.7% of participants), Declining (5.9%), Increasing (26.3%), and High (8.1%). The median of 9-year overall physical activity (MET.minutes/week) was 450 in the Low, 1324 in the Declining, 1399 in the Increasing, and 2323 in the High group. Compared with the Low group, the risks of diabetes, obesity and physical disability were lower in the Increasing and High groups, and the risk of depression was lower in the High group. Conversely, the risk of obesity was higher in the Declining group. CONCLUSIONS: Targeting mid-aged women with declining physical activity for prevention programs could enhance health in later life.

Physical activity volume, frequency, and intensity: Associations with hypertension and obesity over 21 years in Australian women.

BACKGROUND: Optimal patterns of accrual of recommended levels of physical activity (PA) for prevention of hypertension and obesity are not known. The overall aim of this study was to investigate whether different patterns of accumulation of PA are differentially associated with hypertension and obesity in Australian women over 21 years. Specifically, we investigated whether, for the same weekly volume of PA, the number of sessions (frequency) and vigorousness of PA (intensity) were associated with a reduction in the occurrence of hypertension and obesity in women. METHODS: Data from the 1973-1978 and 1946-1951 cohorts of the Australian Longitudinal Study on Women's Health were analyzed (n = 20,588; 12%-16% with a Bachelor's or higher degree). Self-reported PA, hypertension, height, and weight were collected using mail surveys every 3 years from 1998/2000 to 2019/2021. Generalized Estimating Equation models with a 3-year lag model were used to investigate the association of PA volume (metabolic equivalent min/week) (none; 33-499; 500-999; ≥1000, weekly frequency (none; 1-2 times; 3-4 times; 5-7 times; ≥8 times), and the proportion of vigorous PA to total volume of PA (none; 0%; 1%-33%; 34%-66%; 67%-100%) with odds of hypertension and obesity from 2000 to 2021. RESULTS: The cumulative incidence of hypertension was 6% in the 1973-1978 and 23% in the 1946-1951 cohort; 27% of women in the 1973-1978; and 15% in the 1946-1951 cohort developed obesity over the period. Overall, a higher volume of PA was associated with reduced odds of hypertension and obesity. When the volume of PA was considered, the odds of hypertension did not vary according to the frequency or intensity of PA. However, increased proportion of vigorous PA to the total volume of PA was associated with a small additional reduction in the risk of obesity. CONCLUSION: PA volume appears to be more important than the pattern of accumulation for the prevention of hypertension and obesity. Incorporating more sessions, particularly of vigorous-intensity PA, may provide extra benefits for the prevention of obesity.

Physical activity across midlife and health-related quality of life in Australian women: A target trial emulation using a longitudinal cohort.

BACKGROUND: There is little long-term causal evidence on the effect of physical activity on health-related quality of life. This study aimed to examine the associations between longitudinal patterns of physical activity over 15 years and health-related quality of life in both the physical and mental health domains, in a cohort of middle-aged Australian women. METHODS AND FINDINGS: We used data collected at 3-year intervals (1998 to 2019) from 11,336 participants in the Australian Longitudinal Study on Women's Health (ALSWH) (1946 to 1951 birth cohort). Primary outcomes were the physical (PCS) and mental health component summary (MCS) scores (range from 0 to 100; higher scores indicate higher perceived physical/mental health) from the SF-36 in 2019 (when women aged 68 to 73 years). Using target trial emulation to imitate a randomized controlled trial (RCT), we tested 2 interventions: (1) meeting the World Health Organization (WHO) physical activity guidelines consistently throughout the 15-year "exposure period" (2001 to 2016; when women aged 50-55 to 65-70 years; physical activity assessed every 3 years); and (2) not meeting the guidelines at the beginning of the exposure period but starting to first meet the guidelines at age 55, 60, or 65; against the control of not meeting the guidelines throughout the exposure period. Analysis controlled for confounding using marginal structural models which were adjusted for sociodemographic and health variables and conditions. Consistent adherence to guidelines during the exposure period (PCS: 46.93 [99.5% confidence interval [CI]: 46.32, 47.54]) and first starting to meet the guidelines at age 55 (PCS: 46.96 [99.5% CI: 45.53, 48.40]) were associated with three-point higher PCS (mean score difference: 3.0 [99.5% CI: 1.8, 4.1] and 3.0 [99.5% CI:1.2, 4.8]) than consistent non-adherence (PCS: 43.90 [99.5% CI: 42.79, 45.01]). We found a similar pattern for most SF-36 subscales but no significant effects of the interventions on MCS. The main limitations of the study were that it may not account for all underlying health conditions and/or other unmeasured or insufficiently measured confounders, the use of self-reported physical activity and that findings may not be generalizable to all mid-age women. CONCLUSIONS: Results from the emulated RCT suggest women should be active throughout mid-age, ideally increasing activity levels to meet the guidelines by age 55, to gain the most benefits for physical health in later life.

Association of 'Tortoise' and 'Hare' movement behavior patterns with cardiometabolic health, body composition, and functional fitness in older adults.

We investigated the association of movement behavior patterns with cardiometabolic health, body composition, and functional fitness in older adults. A total of 242 older adults participated of this cross-sectional study. Sedentary time, light physical activity (LPA) and moderate-vigorous physical activity (MVPA), steps/day, and step cadence were assessed by accelerometry. The movement behavior patterns were derived by principal component analysis. Cardiometabolic health was defined by a metabolic syndrome score (cMetS). Body composition was determined by appendicular lean mass/body mass index (ALM/BMI). Functional fitness was assessed by a composite z-score from the Senior Fitness Test battery. Two patterns were identified: 'Tortoise' (low sedentary time, high LPA and steps/day) and 'Hare' (high MVPA, steps/day, and step cadence). 'Tortoise' and 'Hare' were associated with better cMetS. 'Hare' was positively associated with ALM/BMI and Functional Fitness. While 'Tortoise' and 'Hare' were associated with better cMetS, only 'Hare' was associated with better ALM/BMI and functional fitness.

Relationship of device measured physical activity type and posture with cardiometabolic health markers: pooled dose-response associations from the Prospective Physical Activity, Sitting and Sleep Consortium.

AIMS/HYPOTHESIS: The aim of this study was to examine the dose-response associations of device-measured physical activity types and postures (sitting and standing time) with cardiometabolic health. METHODS: We conducted an individual participant harmonised meta-analysis of 12,095 adults (mean ± SD age 54.5±9.6 years; female participants 54.8%) from six cohorts with thigh-worn accelerometry data from the Prospective Physical Activity, Sitting and Sleep (ProPASS) Consortium. Associations of daily walking, stair climbing, running, standing and sitting time with a composite cardiometabolic health score (based on standardised z scores) and individual cardiometabolic markers (BMI, waist circumference, triglycerides, HDL-cholesterol, HbA1c and total cholesterol) were examined cross-sectionally using generalised linear modelling and cubic splines. RESULTS: We observed more favourable composite cardiometabolic health (i.e. z score <0) with approximately 64 min/day walking (z score [95% CI] -0.14 [-0.25, -0.02]) and 5 min/day stair climbing (-0.14 [-0.24, -0.03]). We observed an equivalent magnitude of association at 2.6 h/day standing. Any amount of running was associated with better composite cardiometabolic health. We did not observe an upper limit to the magnitude of the dose-response associations for any activity type or standing. There was an inverse dose-response association between sitting time and composite cardiometabolic health that became markedly less favourable when daily durations exceeded 12.1 h/day. Associations for sitting time were no longer significant after excluding participants with prevalent CVD or medication use. The dose-response pattern was generally consistent between activity and posture types and individual cardiometabolic health markers. CONCLUSIONS/INTERPRETATION: In this first activity type-specific analysis of device-based physical activity, ~64 min/day of walking and ~5.0 min/day of stair climbing were associated with a favourable cardiometabolic risk profile. The deleterious associations of sitting time were fully attenuated after exclusion of participants with prevalent CVD and medication use. Our findings on cardiometabolic health and durations of different activities of daily living and posture may guide future interventions involving lifestyle modification.

Maternal physical activity and sitting time and its association with placental morphology and blood flow during gestation: Findings from the Queensland Family Cohort study.

OBJECTIVES: Antenatal exercise is associated with placental morphological alterations, however research in this area is limited. Given the emphasis on the beneficial effects of antenatal exercise, it is important to understand its effect on placental function and the relationship to foetal development. The aim of this study was to investigate the association between physical activity, sitting time, and placental outcomes measured during gestation. DESIGN: Prospective cohort study. METHODS: Pregnant women in the Queensland Family Cohort study self-reported physical activity at 24 and 36 weeks of gestation (n = 203) and were categorised into physical activity volume groups of nil-low (0-<500 metabolic equivalent of task·minutes/week), moderate (500-<1000 metabolic equivalent of task·minutes/week), or high-volume activity (≥1000 metabolic equivalent of task·minutes/week). Participants reported average daily sitting time, whereby excessive sitting time was considered as ≥8h/day. Placental stiffness, thickness, and uteroplacental blood flow resistance were measured by ultrasound imaging at each timepoint. RESULTS: Physical activity volume was not associated with changes to placental morphometrics or uteroplacental blood flow resistance at 24 or 36 weeks of gestation. Excessive sitting time at 36 weeks was associated with greater placental stiffness (p = 0.046), and a lower umbilical artery pulsatility index (p = 0.001). CONCLUSIONS: Placental tissue stiffness and umbilical artery resistance were altered in late gestation with higher maternal sitting time but not with physical activity volume. Overall, excessive sitting time may be a risk for suboptimal placental function and could be an important focus for antenatal care.

Pain exacerbation following physical activity in adults with diabetic neuropathy: Ecological momentary assessment of foot symptoms.

BACKGROUND AND OBJECTIVES: People with diabetic peripheral neuropathy (DPN) report fluctuating foot symptoms. This study used ecological momentary assessment to: (1) compare foot symptoms between days, time points and periods with/without preceding physical activity or pain medication; and (2) determine relationships between symptoms and endogenous pain modulation. METHOD: Ten low-active Australian adults with probable DPN underwent temporal summation of pain (TSP) and conditioned pain modulation (CPM) then completed mobile phone surveys five times daily for seven days, where they recorded the intensity of six foot symptoms and whether they performed physical activity or consumed pain medication in the preceding three hours.  RESULTS: All foot symptoms except numbness were greater in periods following physical activity, whereas periods following pain medication showed greater shooting pain. TSP showed very large correlations with sensitivity to touch, burning pain, shooting pain and prickling/tingling.  DISCUSSION: General practitioners should be aware that physical activity might exacerbate symptoms of DPN when encouraging their patients to be active.

Trajectories of physical activity from mid to older age in women: 21 years of data from the Australian Longitudinal Study on Women's Health.

BACKGROUND: Women's physical activity varies across the adult lifespan. However, changes in physical activity among mid-aged women are not well understood. We analysed 21 years of data from women born in 1946-51 to identify: (1) trajectories of physical activity in the transition from mid- to old-age and (2) determinants of different physical activity trajectories. METHODS: Data were from the 1946-51 cohort of the Australian Longitudinal Study on Women's Health (N = 10,371). Surveys were mailed at three-year intervals from 1998 (age 47-52) to 2019 (age 68-73) to collect data on physical activity, sociodemographic factors (country of birth, area of residence, educational attainment, marital status, income management, paid work hours, living with children age < 18, providing care), health indicators (menopause status, BMI, physical and mental health, chronic conditions), and health behaviours (smoking, alcohol status). Group-based trajectory modelling was used to identify trajectories of physical activity. Multinomial logistic regression models were used to examine the determinants of physical activity trajectories. RESULTS: Five trajectories were identified: Low-stable (13.3% of participants), Moderate-stable (50.4%), Moderate-increasing (22.2%), High-declining (7.7%), and High-stable (6.6%). Sociodemographic characteristics (area of residence, education, income management, living with children, and providing care) were determinants of physical activity trajectories, but the strongest factors were BMI, physical and mental health. Women who were overweight/obese and had poor physical and mental health were less likely to be in the High-stable group than in any other group. Changes in these variables (increasing BMI, and declining physical and mental health) and in marital status (getting married) were positively associated with being in trajectories other than the High-stable group. CONCLUSIONS: Although most women maintained physical activity at or above current guidelines, very low physical activity levels in the Low-stable group, and declining levels in the High-declining group are concerning. The data suggest that physical activity promotion strategies could be targeted to these groups, which are characterised by socioeconomic disadvantage, high (and increasing) BMI, and poor (and worsening) physical and mental health. Removing barriers to physical activity in these women, and increasing opportunities for activity, may reduce chronic disease risk in older age.

Associations Between Intersecting Sociodemographic Characteristics and Device-Measured Physical Activity Among Children and Adolescents Living in the United States.

BACKGROUND: Despite robust evidence demonstrating sociodemographic characteristics may underly some of the disparities in physical activity observed among children and adolescents, the often-overlooked nexus of potential interactions between these characteristics warrants further exploration. This study explored the intersectionality of gender, race/ethnicity, parental education, and household income in relation to device-measured physical activity volume and intensity in a nationally representative sample of US children and adolescents. METHODS: Cross-sectional data from 3 cycles of the US National Health and Nutrition Survey (2011-2012; 2012 National Youth Fitness Survey; and 2013-2014) were used. A total of 6116 participants (49% female) between 3 and 17 years of age wore an accelerometer on their nondominant wrist for 7 days. Monitor-independent movement summary units were used to represent physical activity volume and intensity. A Social Jeopardy Index was created to represent increasing levels of intersecting social disadvantages based on combinations of gender, race/ethnicity, parental education, and household income-to-poverty ratio tertiles. Generalized linear regression models were computed. RESULTS: The results showed social disadvantages become increasingly evident among children and adolescents during the most intense 60 minutes of daily physical activity (B = -48.69 [9.94] SE, P < .001), but disparities in total volume were not observed (B = 34.01 [44.96] SE, P = .45). CONCLUSIONS: Findings suggest that patterns of physical activity behavior may differ based on intersecting sociodemographic characteristics-more socially disadvantaged children and adolescents appear to accumulate activity at lighter intensities. Collecting contextual information about device-measured physical activity represents an important next step for gaining insight into these sociodemographic differences.

Cross-sectional and prospective associations between screen time and childhood neurodevelopment in two Brazilian cohorts born 11 years apart.

BACKGROUND: The aim of this study was to investigate the associations between screen time from ages 2 to 4 years and child neurodevelopment at age 4. METHODS: The participants were from the 2004 (N = 3787) and 2015 (N = 3604) Pelotas (Brazil) birth cohort studies. Childhood neurodevelopment was assessed at age 4 using the Battelle Development Inventory. The time children spent on screen devices was reported by their guardians at ages 2 and 4 years. Linear regression models were used to investigate the association of: (i) time spent on television at ages 2 and 4 years; (ii) time spent on other screens at age 4; and (iii) total screen time at age 4 (television + other screens) with childhood neurodevelopment at age 4. RESULTS: Average daily screen time among children born in 2004 and those born in 2005 aged 4 years were 3.4 (SD: 2.4) and 4.4 h (SD: 2.9), respectively. Overall, few associations of very small magnitude between screen time and child neurodevelopment were observed. Television time at 2 years of age was statistically associated with lower neurodevelopment at 4 years of age in the 2015 cohort (ß = -0.30, 95%CI = -0.55; -0.05). Conversely, television time (ß = 0.17, 95%CI = 0.07, 0.26) and total screen time (ß = 0.22, 95%CI = 0.13, 0.31) at age 4 were associated with higher neurodevelopment at age 4 in the 2004 cohort. CONCLUSIONS: The findings of this study suggest that the amount of time spent on screen devices might not be associated with neurodevelopment of children under 5 years of age. The small magnitude and inconsistencies in the direction of associations did not find evidence to support the current guidelines for screen time at this age. Therefore, more studies, especially those with longitudinal data, are important to comprehend the true effect of screen time on neurodevelopment and other health outcomes.

Examination of Physical Activity, Organized Sport, and Sitting Time Among Women and Mothers From Culturally and Linguistically Diverse Backgrounds.

BACKGROUND: Little evidence is available from culturally and linguistically diverse (CALD) communities on the association between motherhood and physical activity (PA). This study aimed to examine independent and joint associations of cultural background and motherhood with meeting PA guidelines, participation in organized sports, and high sitting time (>8 h/d). METHODS: We used self-reported cross-sectional data from survey 8 of the 1973-1978 cohort of the Australian Longitudinal Study on Women's Health. PA was measured using the Active Australia Survey while organized sport and sitting time were measured using single items. CALD was defined as being born in a non-English speaking country or primarily speaking a non-English language at home. Multivariable-adjusted logistic regression analyses were used to examine independent and joint associations. RESULTS: Data from 5967 women (mean age 42.4 [SD 1.5] y, 6.9% CALD, 81.2% mothers) were analyzed. Women of CALD background had lower odds of meeting PA guidelines (odds ratio; 95% confidence interval: 0.80; 0.64-0.98) and participation in organized sports (0.68; 0.54-0.86), but no statistically significant association with sitting time (0.90; 0.72-1.14). Mothers had lower odds of meeting PA guidelines (0.75; 0.64-0.87) and high sitting time (0.42; 0.36-0.49). Compared with non-CALD women without children, mothers (irrespective of cultural background) were less likely to meet PA guidelines and have high sitting time. The association of "cultural background and motherhood" with organized sports participation was only significant for CALD mothers. CONCLUSIONS: Increased efforts and investments are needed to ensure that sports and other PA promotion interventions are culturally sensitive and engaging for CALD women and those with children.

Prepregnancy maternal BMI and trajectories of BMI-for-age in children up to four years of age: findings from the 2015 Pelotas (Brazil) birth cohort.

BACKGROUND: The aims of the study were to: (a) describe BMI-for-age trajectories in children up to four years of age; (b) evaluate the association between prepregnancy maternal BMI and the BMI-for-age trajectories. METHODS: Data from 3218 (75.3% of the original cohort) children from the Pelotas 2015 Birth Cohort were analyzed. Prepregnancy BMI (kg/m2) was measured on the perinatal interview. Z-scores of BMI-for-age were calculated for children at three months, 1, 2 and 4 years. Trajectories were identified using a semi-parametric group-based modeling approach. Multinomial logistic regression was used to test the association between prepregnancy BMI (weight excess: BMI ≥ 25 kg/m2) and BMI-for-age trajectories. RESULTS: Four trajectories of the BMI-for-age, in z-score, were identified and represent children in the "increasing", "adequate", "stabilized" and "risk for weight excess" group. A total of 196 children (7.1%) belonged to the group that was at risk of weight excess. Adjusted analyses showed that children whose mothers presented prepregnancy weight excess had 2.36 (95%CI 1.71; 3.24) times more risk of belonging to group "risk for weight excess" when compared to those children whose mothers presented underweight/normal weight before pregnancy. CONCLUSION: The risk of weight excess in children up to 4 years of age were greater in mothers who presented prepregnancy weight excess.