High Sedentary Behavior Research Articles

Association between resting heart rate and cardiovascular risk factors in adolescents.

Our study demonstrated that while RHR was associated with cardiovascular risk factors in both sexes, the clustering of risk factors amplified the elevation of RHR in a gender-dependent fashion. • Resting heart rate is a marker of cardiovascular disease and mortality in adults and associated with risk factor such as higher levels of blood pressure, triglycerides, glucose, and obesity in children and adolescents. • The data from the current study suggest that the risk factor clustering is associated with elevated resting heart rate in adolescents and that the clustering of risk factors amplifies the elevation of resting heart rate in a gender-dependent fashion.

Patterns of physical activity and sedentary behaviour in the general population in France: cluster analysis with personal and socioeconomic correlates.

Few studies have focused on relating physical activity (PA) and sedentary behaviour (SB) to identify homogeneous groups. This study aimed to identify patterns of PA and SB in France general population and their correlates. A sample of 3294 (mean age 44 ± 17 years) from the general population in France was included. PA and SB were assessed by the World Health Organization Global Physical Activity Questionnaire. Cluster analysis was used to identify PA and SB patterns, with polytomous logistic regression to identify their correlates. Five clusters were identified: (i) 'low total PA, active-transportation and low SB' (41%), (ii) 'low total PA and moderate SB' (22%), (iii) 'low total PA, leisure-time PA and high SB' (15%), (iv) 'high total PA, moderate occupational PA and moderate SB' (17%) and (v) 'high total PA, vigorous occupational PA and low SB' (5%). Occupational PA substantially contributed to total PA which depended on socioeconomic status (SES): low total PA and high SB in higher SES and high total PA and low SB in lower SES. Based on PA and SB, French adults were clustered into groups with socioeconomic differences emphasizing that adapted interventions may be more beneficial for health.

Clustering of lifestyle behaviours and relation to body composition in European children. The IDEFICS study.

Dietary patterns, physical activity (PA) and sedentary behaviours are some of the main behavioural determinants of obesity; their combined influence in children has been addressed in a limited number of studies. Children (16,228) aged 2-9 years old from eight European countries participated in the baseline survey of the IDEFICS study. A subsample of 11,674 children (50.8% males) were included in the present study. Children's food and beverage consumption (fruit and vegetables (F&V) and sugar-sweetened beverages (SSBs)), PA and sedentary behaviours were assessed via parental questionnaires. Sex-specific cluster analysis was applied to identify behavioural clusters. Analysis of covariance and logistic regression were applied to examine the association between behavioural clusters and body composition indicators (BCIs). Six behavioural clusters were identified (C1-C6) both in boys and girls. In both sexes, clusters characterised by high level of PA (C1 and C3) included a large proportion of older children, whereas clusters characterised by low SSB consumption (C5 and C6) included a large proportion of younger children. Significant associations between derived clusters and BCI were observed only in boys; those boys in the cluster with the highest time spent in sedentary activities and low PA had increased odds of having a body mass index z-score (odds ratio (OR)=1.33; 95% confidence interval (CI)=(1.01, 1.74)) and a waist circumference z-score (OR=1.41; 95%CI=(1.06, 1.86)) greater than one. Clusters characterised by high sedentary behaviour, low F&V and SSB consumption and low PA turned out to be the most obesogenic factors in this sample of European children.

Differential Item Functioning Analysis Of The Physical Activity Enjoyment Scale

BACKGROUND: Enjoyment is a commonly reported motivation for engaging in physical activity and may be a key mediator of exercise promoting interventions for teens. Given the burden of physical inactivity in the US, identification of correlates and potential targets of intervention to promote activity are needed. The Physical Activity Enjoyment Scale (PACES) represents a promising tool to evaluate patterns of physical activity and sedentary behavior among teens. Continued validation for use with multi-ethnic teens is needed, particularly among Hispanic teens who may be characterized by risk factors associated with lower engagement in physical activity and higher sedentary behavior. METHOD: A school-based sample of 9th Grade Hispanic (N = 1605; mean age = 14.6 years, SD = .41) and Non-Hispanic White (N = 544; mean age = 14.6 years, SD = .39) students completed in-classroom self-report measures of physical activity (PA), sedentary behavior (SED), and the PACES. Full Information Maximum likelihood confirmatory factor analysis and item response models (IRM) of the Positive and Negative PACES subscales assessed construct validity and Differential Item Functioning (DIF) of the 14-item PACES among Latino and Non-Latino adolescents. RESULTS: Non-parametric IRM suggested modifications to the response format for negatively worded subscale of the PACES. A two-factor model reflecting both positive and negative subscales provided better fit than a unidimensional model (X2= 4755.0, p<0.001). Loadings on primary factors ranged from 0.87-0.94 for positive and 0.78-0.96 for negative experiences subscales. Internal consistency estimates were 0.95 and 0.90 for positive and negative scales, respectively. DIF analyses supported measurement invariance and construct validity of both subscales across Hispanic and Non-Hispanic White respondents. PACES-Positive and PACES-Negative maintained significant correlations with levels of physical activity (r=0.38 & r=-0.31, respectively) and moderate to vigorous physical activity (r=0.31 & r=-0.19, respectively). CONCLUSIONS: We found support for the construct validity, concurrent validity and consistency of measurement of the 14-item PACES provides for use in comparing positive and negative experiences of exercise among both Non-Hispanic White and Hispanic teens.

Maternal undernutrition and cardiometabolic disease: a Latin American perspective.

The current epidemic of obesity and cardiometabolic diseases in developing countries is described as being driven by socioeconomic inequalities. These populations have a greater vulnerability to cardiometabolic diseases due to the discrepancy between the maternal undernutrition and its consequence, low-birth weight progeny, and the subsequent modern lifestyles which are associated with socioeconomic and environmental changes that modify dietary habits, discourage physical activity and encourage sedentary behaviors. Maternal undernutrition can generate epigenetic modifications, with potential long-term consequences. Throughout life, people are faced with the challenge of adapting to changes in their environment, such as excessive intake of high energy density foods and sedentary behavior. However, a mismatch between conditions experienced during fetal programming and current environmental conditions will make adaptation difficult for them, and will increase their susceptibility to obesity and cardiovascular diseases. It is important to conduct research in the Latin American context, in order to define the best strategies to prevent the epidemic of cardiometabolic diseases in the region.

The Effects of Sedentary Behavior on Metabolic Syndrome Independent of Physical Activity and Cardiorespiratory Fitness

Background: To date, no longitudinal studies have examined the influence of sedentary behavior on metabolic syndrome development while accounting for cardiorespiratory fitness. Purpose and Methods: This prospective study examined the relationship between sedentary behavior and incident metabolic syndrome while considering the effects of physical activity and cardiorespiratory fitness on the association among 930 men enrolled in the Aerobics Center Longitudinal Study. Results: A total of 124 men developed metabolic syndrome during 8974 person-years of exposure. After adjusting for covariates, men with middle and high sedentary behavior had 65% and 76% higher risks of developing metabolic syndrome, respectively, than men with low sedentary behavior (linear trend P = .011). This association remained significant after additional adjustment for activity status and cardiorespiratory fitness. Cardiorespiratory fitness and physical activity were also inversely associated with metabolic syndrome, even after adjustment for sedentary behavior. Conclusions: The findings highlight the importance of reducing sedentary behavior, increasing physical activity, and improving cardiorespiratory fitness for preventing metabolic syndrome.

The effects of sedentary behavior on metabolic syndrome independent of physical activity and cardiorespiratory fitness.

To date, no longitudinal studies have examined the influence of sedentary behavior on metabolic syndrome development while accounting for cardiorespiratory fitness. This prospective study examined the relationship between sedentary behavior and incident metabolic syndrome while considering the effects of physical activity and cardiorespiratory fitness on the association among 930 men enrolled in the Aerobics Center Longitudinal Study. A total of 124 men developed metabolic syndrome during 8974 person-years of exposure. After adjusting for covariates, men with middle and high sedentary behavior had 65% and 76% higher risks of developing metabolic syndrome, respectively, than men with low sedentary behavior (linear trend P = .011). This association remained significant after additional adjustment for activity status and cardiorespiratory fitness. Cardiorespiratory fitness and physical activity were also inversely associated with metabolic syndrome, even after adjustment for sedentary behavior. The findings highlight the importance of reducing sedentary behavior, increasing physical activity, and improving cardiorespiratory fitness for preventing metabolic syndrome.

Mobility disability and the pattern of accelerometer-derived sedentary and physical activity behaviors in people with multiple sclerosis

ObjectiveLow physical activity and high sedentary behavior levels are major concerns in persons with multiple sclerosis (MS) and these differ depending on the level of mobility disability. However, the manner in which daily activity is accumulated is currently unknown in this population. MethodsA secondary analysis was performed on a combined data set of persons with MS from two previous investigations of physical activity and symptomatic or quality of life outcomes in the United States over a two year period (2007–2009). Mobility disability status was determined using the Patient Determined Disease Steps (PDDS) while activity behavior was objectively monitored using an ActiGraph accelerometer for 7days. ResultsPersons with MS who have mobility disability were involved in sedentary behavior, light and moderate intensity activity for 65%, 34% and 1% of the day, respectively compared to 60%, 37%, and 3%, respectively in those without mobility disability (p<0.05). Breaks in sedentary time did not differ by mobility disability status. Compared to those without mobility disability, the average number of sedentary bouts longer than 30min was greater in those with mobility disability (p=0.016). ConclusionPersons with MS with mobility disability are less active, engage in more sedentary behavior and accumulate prolonged sedentary bouts.

The association between sedentary behaviour, moderate–vigorous physical activity and frailty in NHANES cohorts

Objectives(1) To examine how sedentary behaviour and moderate–vigorous (MVPA) are each experienced during the day across different levels of frailty; (2) estimate and compare the extent to which high levels of sedentary behaviour and low levels of MVPA are associated with increased frailty and self-reported health, disability and healthcare utilization. MethodsCommunity dwelling adults aged 50+ from the National Health and Nutrition Examination Survey (2003–2004; 2005–2006). Frailty was measured with the frailty index and physical activity was measured using ActiGraph accelerometers. ResultsOn average, people engaged in about 8.5h of sedentary behaviour each day. The most frail individuals were more sedentary and less likely to meet weekly MVPA guidelines (9.57h/day; 8.3%) than non-frail individuals (8.18h/day; 1.1%; p<0.001). Frail individuals failed to demonstrate the patterns of the healthier individuals—higher levels of sedentary behaviour on Sundays and in the evenings and decreasing MVPA throughout the week. High sedentary behaviour and low MVPA were independently associated with higher levels of frailty, poor self-reported health, high ADL disability and higher healthcare usage. ConclusionsMany people over the age of 50, and most of those who are frail, were highly sedentary with very few meeting the recommended weekly levels of MVPA. Sedentary behaviour and MVPA were independently associated with frailty and adverse health outcomes in middle to older aged adults. Future research should focus on a longitudinal study to determine the temporal relationship between sedentary behaviour and frailty.

Association between adolescents' physical activity and sedentary behaviors with change in BMI and risk of type 2 diabetes.

This study aims at identifying the association between physical activity (PA) and sedentary behavior (SB) patterns during adolescents on the future increase in BMI and risk of diabetes during young adulthood. A total of 3,717 participants aged 11 to 21 at baseline who completed Waves I (1994–1995), II (1996), III (2001–2002), and IV (2008) surveys of the National Longitudinal Study of Adolescent Health (Add Health) were analyzed. Physical activity and sedentary behavior patterns were assessed using an interviewer-administered questionnaire at Waves I, II, and III. A participant was classified as having diabetes at Wave IV according to WHO guidelines. The k-means cluster analysis was used to identify the number of PA and SB patterns assessed using interviewer-administered questionnaire. The k-means cluster analysis identified three clusters; 575 (15.5%), 2,140 (57.6%), and 1,002 (27.0%) participants belonged to the low PA high SB (LPAHSB), the LPALSB, and the HPALSB cluster respectively. Relative to the LPALSB cluster, the HPALSB cluster had lower increase in BMI from Wave III to Wave IV (P = 0.03), whereas the difference between LPAHSB cluster and LPALSB cluster was not significant (P = 0.09). The odds of developing diabetes at Wave IV was significant for the LPAHSB cluster (OR = 1.69, 95% CI = 1.04, 2.75) but not significant for the HPALSB cluster (OR = 0.87, 95% CI = 0.52, 1.47) relative to the LPALSB cluster. To conclude, PA but not SB during adolescence predicted change in BMI during young adulthood. SB but not PA during adolescence predicted type 2 diabetes during young adulthood.

Lifestyle practices and obesity in Malaysian adolescents.

Aim: To determine the influence of physical activity (PA) and sedentary behavior (SB) on obesity profiles of 454 Malaysian adolescents aged 12 to 19. Methods: Validated PA and SB questionnaires were used and body composition assessed using anthropometry and dual-energy X-ray absorptiometry (DXA). Results: Gender-specific multivariate analyses showed boys with high levels of total PA and moderate-to-vigorous physical activity (MVPA) exhibited significantly lower levels of total body fat, percent body fat and android fat mass compared with low PA and MVPA groups, after adjusting for potential confounders. Girls with high SB levels showed significantly higher BMI, waist circumference and DXA-derived body fat indices than those at lower SB level. Multiple logistic analyses indicated that boys with low levels of total PA and MVPA had significantly greater obesity risk, 3.0 (OR 3.0; 95% CI, 1.1–8.1; p < 0.05) and 3.8-fold (OR 3.8; 95% CI, 1.4–10.1; p < 0.01), respectively, than more active boys. Only in girls with high SB level was there a significantly increased risk of obesity, 2.9 times higher than girls at low SP levels (OR 2.8; 95% CI, 1.0–7.5; p < 0.05). Conclusions: The present findings indicate that higher PA duration and intensity reduced body fat and obesity risk while high screen-based sedentary behaviors significantly adversely influenced body fat mass, particularly amongst girls when the PA level was low.

An inactive lifestyle and low physical fitness are associated with functional somatic symptoms in adolescents. The TRAILS study

ObjectiveAn inactive lifestyle has been associated with functional somatic symptoms (FSS), but findings are contradictory. Moreover, mediating factors in this relationship are unclear. We examined whether low physical activity was related to FSS in adolescents, and whether this association was mediated by low physical fitness. MethodsThis study was part of the Dutch longitudinal cohort study TRAILS, in which 1816 adolescents (mean age 16.3years, SD 0.7) participated during the third (T3) and 1881 (mean age 19.1years, SD 0.6) during the fourth (T4) assessment waves. Adolescents' exercise and sedentary behavior levels and the number of FSS were assessed by questionnaires at T3 and T4. Physical fitness (VO2Max) was determined for 687 adolescents by a shuttle run test at T3. The association between physical activity and FSS was examined with bootstrapped linear regression analyses, adjusted for smoking and gender. In addition, bootstrapped mediation analyses were performed. ResultsA lack of exercise (b=0.05, bootstrap 95%-CI: 0.01 to 0.09) and high sedentary behavior (b=0.10, bootstrap 95%-CI: 0.06 to 0.14) at T3 were positively associated with FSS at T3. Since no longitudinal effects were found, shared associations were tested instead of mediation. The associations between a lack of exercise and FSS, and sedentary behavior and FSS were shared with physical fitness (b=0.01, bootstrap 95%-CI: 0.010.02. and b=0.03, bootstrap 95%-CI: 0.010.05). ConclusionAn inactive lifestyle is associated with increased FSS in adolescents. Only part of this association is shared with low physical fitness.

Physical activity: From epidemiological evidence to individualized patient management

BackgroundPhysical activity (PA), physical fitness (PF), and even a few sedentary behaviors (SB) are strongly and independently linked to improved survival rate. However, key questions remain: what are the physiological interrelationships between SB, PA, and PF? How should we differently emphasize promoting PA, increasing PF with exercise, and decreasing SB among other prevention measures? What are the interrelationships of both PA and SB levels with drug treatment efficacy? MethodsTo address these questions we developed an integrated patient-centric model combining physiology with epidemiological evidence to characterize the individual risk attached to PA level, PF, and SB. Epidemiological data were collected by extensive literature review. ResultsNine meta-analyses, 198 cohort studies (3.8million people), and 13 controlled trials were reviewed.1.A high level of SB induces chronic stress and increases the risk of both chronic disease and mortality.2.Vigorous PA increases PF and physiological reserve, thereby improving survival rate. This effect is not mediated by improved traditional risk factors.The risk for most individuals is a mix of high SB, low to mild PA, and low to mild PF.This model can improve the individualized prescription of PA modalities. Furthermore, the benefit of treatments such as statins or beta-blockers can be cancelled out if a decrease in PA or an increase in SB is induced by drug related side effects. ConclusionsTo improve patient management both types of therapeutic interventions and dose should be carefully chosen for each individual in order to maintain/increase PA level while decreasing SB.

Associations of sedentary behavior and physical activity with psychological distress: a cross-sectional study from Singapore.

BackgroundEmerging evidence suggests the adverse association between sedentary behaviour (SB) with physical and mental health, but few studies have investigated the relationship between volume of physical activity and psychological distress. The present study examined the independent and interactive associations of daily SB and weekly level of moderate to vigorous physical activity (MVPA) with psychological distress in a multi-ethnic Asian population.MethodsDe-identified data of 4,337 adults (18–79 years old) on sedentary behaviors, physical activity patterns, psychological distresses, and other relevant variables were obtained from the Singapore Ministry of Health’s 2010 National Health Survey. Psychological distress was assessed using General Health Questionnaire-12 (GHQ-12), whereas total daily SB and total weekly volume (MET/minutes) of MVPA were estimated using the Global Physical Activity Questionnaire version 2 (GPAQ v2). Multivariate logistic regression analyses were carried out to estimate the odds ratios (95% confidence intervals) of the independent and interactive relationships of SB and MVPA with prevalence of psychological distress.ResultsThe category of high SB was positively associated with increased odds (OR = 1.29, 1.04-1.59) for psychological distress, whereas the category of active was inversely associated with lower odds (OR = 0.73, 0.62-0.86) for psychological distress. Multivariate analyses for psychological distress by combined daily SB and weekly MVPA levels showed inverse associations between middle SB and active categories (OR = 0.58, 0.45 - 0.74) along with low SB and active categories (OR = 0.61, 0.47-0.80).ConclusionsThe present population-based cross-sectional study indicated that in the multi-ethnic Asian society of Singapore, a high level of SB was independently associated with psychological distress and meeting the recommended guidelines for physical activity along with ≤ 5 h/day of SB was associated with the lowest odds of psychological distress.

Fatores associados ao comportamento sedentário em escolares de 9-12 anos de idade

São recentes os estudos que investigaram impactos do comportamento sedentário (CS) sobre a saúde, principalmente em crianças. O objetivo foi investigar fatores associados ao CS em escolares do município de Uberaba, MG. Trata-se de estudo epidemiológico, transversal, com amostra probabilística (n = 649). Foram coletadas e consideradas variáveis independentes: medidas antropométricas, pressão arterial, exames bioquímicos, tempo gasto em atividade física (AF). CS foi considerado variável dependente, caracterizado pelo tempo de tela (TT), e verificado fatores associados pela regressão de Poisson. Meninas apresentaram valores maiores de dobras cutâneas, triglicerídeos e HDL-c e meninos, maior concentração de glicose sanguínea, atenderam mais à recomendação de 60 min de AF/dia e maior CS. O TT &gt; 2 h/dia foi prevalente em 76,9 % da amostra. CS não foi associado a variáveis sociodemográficas, de saúde e comportamentais em crianças de 9-12 anos de idade. Mais pesquisas são necessárias para elucidar as inter-relações complexas entre TT e fatores associados.

Abstract 054: Associations of Physical Activity and Sedentary Behavior with Healthy Survival, Disease, Disability, and Death in Older Women

Background: Physical activity decreases and time spent sedentary increases with age. Evidence suggests that even modest levels of physical activity may reduce the risk of disease, disability, and death in older adults. We aimed to quantify the risk of low physical activity and high sedentary behavior on disease (defined as having cardiovascular disease, stroke, cancer, diabetes, and/or hip fracture), mobility disability, and death in women ≥85 years of age. Methods: Women from the Women’s Health Initiative Clinical Trials (CTs) and Observational Study (OS) programs born before September 1, 1925 (therefore, ≥85 years old by September 1, 2010) were categorized into mutually-exclusive groups: 1) no disease and no disability (“healthy”); 2) ≥1 disease but no disability (“diseased”); 3) mobility disabled with or without disease (“disabled”); and 4) died before age 85 years. The associations of baseline physical activity levels, in metabolic equivalent hours/week (MET-hrs/wk), for CT and OS women (n=27,998) and baseline hours/day spent sitting for OS women (n=16,889) comparing “healthy” (reference group) to the other three outcomes were evaluated using polytomous logistic regression. Odds ratios (OR) and 95% confidence intervals (CI), adjusted for race/ethnicity, education, marital status, and baseline age, hormone therapy use, smoking status, alcohol use, body mass index, and depression, were estimated. Results: Baseline age range was 68-81 years. Mean (SD) baseline physical activity level was 12 (13) MET-hrs/wk (range: 0-134). Mean (SD) baseline MET-hrs/wk for women classified as healthy, diseased, disabled, and died were 15 (14), 13 (13), 10 (12), and 11 (12), respectively (p-trend&lt;0.001). Compared to women in the highest physical activity quartile (≥17.5 MET-hrs/wk), the risk of being diseased, disabled, or of dying relative to being healthy increased in a dose-dependent manner for women in the lower three physical activity quartiles. Women in the lowest quartile (0-&lt;2.5 MET-hrs/wk) had the highest risk, with adjusted ORs (95% CIs) for being diseased, disabled, and of dying of 1.4 (1.3-1.6), 2.4 (2.1-2.7), and 2.2 (1.9-2.5), respectively. Similarly, women who spent ≥8 hours/day sitting had a higher adjusted odds (95% CI) of being disabled (1.3 (1.1-1.4)) and of dying (1.2, (1.0-1.3)), but were not at increased risk of being diseased (1.0 (0.9-1.1)), compared to women who spent ≤5 hours/day sitting. Conclusions: For older women, engaging in modest levels of physical activity and avoiding long periods of sedentary behavior may improve the chance of surviving to age 85 years without disease and mobility disability. Since physical activity and sedentary lifestyle are modifiable behaviors, these findings help inform public health strategies aimed at preventing disease and disability in older women, which may help to reduce healthcare costs and improve overall quality of life.

Patterns of weekday and weekend physical activity in youth in 2 Canadian provinces

Few Canadian children are meeting physical activity (PA) guidelines for optimal growth and health. There is little information describing the patterns of PA among Canadian youth, so it is difficult to determine where the deficits occur. The purpose of this study was to identify subgroups of youth and windows of time characterized by low PA and high sedentary behaviour. We conducted a cross-sectional study of 626 youth (aged 10-15 years) in 2 Canadian provinces. The primary exposure variables included geographic setting (rural vs. urban), sex, and days of the week (weekend days vs. weekdays). The primary outcome measures were minutes of light PA, moderate to vigorous physical activity (MVPA), and sedentary behavior, assessed with accelerometry. Compared with weekdays, MVPA was ∼30% lower on weekend days (55.8 ± 23.0 min vs. 38.7 ± 26.7 min; p < 0.001), whereas light PA was ∼15% higher. Significantly more youth achieved an average of >60 min of MVPA on weekdays than on weekend days (46% vs. 22%; p < 0.001). Sex-specific differences in MVPA were more pronounced on weekdays than on weekend days (∼13 vs ∼8 min per day; p < 0.01). Youth in rural settings achieved ∼9 fewer minutes of MVPA daily than youth in urban settings (p < 0.001). In youth 10 to 15 years of age, daily MVPA is lower and light PA is higher on weekend days than on weekdays. Girls and students living in rural areas were particularly vulnerable to low levels of MVPA.

Correlates and implications of high screen time among high and low active Irish nine-year olds

Background: Previous research has indicated that high sedentary behavior (SB) is associated with ill health including weight gain independent of physical activity (PA). The purpose of this analysis was to examine the combined influence of screen time (SB) and PA on risk of overweight/obesity (OW/Ob) in a large nationally representative cohort of 9 year old Irish school children, with particular reference to the risks of high screen time in the most active of these children. A further aim of the analysis was to examine the correlates of high screen time in this cohort.

High Screen Time Is Associated with Asthma in Overweight Manitoba Youth

Objective. Low physical activity and high sedentary behavior are associated with adverse health outcomes, including asthma. The purposes were to (1) determine if low physical activity and/or high screen time increase the risk of asthma and airway hyperresponsiveness (AHR) in youth and (2) determine if weight status modifies these associations. Methods. This is a prospective cohort study of healthy weight and overweight Canadian youth. In 2003–2005, 723 youth (8.6 ± 0.5 years; 34.0% asthma, 55.9% boys) were recruited from the 1995 Manitoba Prospective Cohort Study. In 2008–2010, 489 returned for follow-up measures (30.9% asthma, 56.6% boys). The primary exposure variables were parent-reported physical activity and screen time at 8–10 years of age. The primary outcome measures were pediatric allergist-defined asthma and AHR defined as the provocative concentration of methacholine required to induce a 20% fall in forced expiratory volume in 1 second (FEV1). Results. Low physical activity (≤2 times weekly) was not associated with asthma or AHR. However, high screen time (≥1 hour/day) was associated with a greater odds of asthma at baseline (odds ratio (OR) = 2.01, 95% confidence interval (CI) = 1.20–3.37, p < .01) and follow-up (OR = 2.11, 95% CI = 1.14–3.89, p < .02) versus low screen time. This association was more pronounced among overweight youth (baseline: OR = 3.95, 95% CI = 1.70–9.12, p < .0001; follow-up: OR = 3.22, 95% CI = 1.17–8.86, p < .02). Screen time was not associated with AHR at baseline or follow-up. Conclusions. High screen time increases the risk of asthma, particularly among overweight youth. Screen time, in addition to physical activity, should be included in clinical assessments of youth with asthma.

P2-58 Unhealthy lifestyle patterns associated with waist circumference among adolescents: a school based survey

ObjectiveTo analyse patterns of lifestyle is associated with abdominal obesity in Brazilian adolescents (14–18 years old).MethodsThis school-based survey was carried out among high school students from Maringá/PR/Brazil, (2007) selected through...