human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Asthma is a severe problem among inner city children , and recent evidence suggests that both allergen exposure and lifestyle can impact the disease early in childhood . This study was design ed to investigate the association between physical activity and wheezing among a population of inner city children enrolling in Head Start . The parents of children aged 3 - 5 years responded to a question naire ( N = 144 ) to determine the presence and severity of wheezing and asthma .  Information was also gathered regarding home environment , food frequency , and presence of other allergic diseases . Serum was obtained to measure total IgE and specific IgE levels to common allergens . Height and weight for body mass index were recorded . Lastly , motion sensor wristwatches ( Actiwatch ) were worn continuously by a subset of these children ( n = 54 ) for 6 or 7 days . Physical activity measured with the motion sensor was decreased among children with a history of wheezing . The significant differences involved those measures of activity relating to prolonged or sustained physical activity . The correlates of asthma associated with decreased levels of physical activity included : 1 ) a history of wheezing in the last 12 months , 2 ) the diagnosis of asthma , and 3 ) presentation to the emergency room in the last 12 months for wheezing or asthma . In a preschool-age population , decreased physical activity was observed among children with a history of asthma or wheezing . Decreased physical activity could contribute to persistence of asthma or put children at higher risk for obesity and other chronic diseases Background Little is known about preschool-aged children ’s levels of  physical activity ( PA ) over the course of the day . Using time-stamped data , we describe the levels and patterns of PA in a population -based sample of four-year-old British children . Methods Within the Southampton Women ’s Survey the PA levels of 593 4-year-old children ( 51 % female ) were measured using ( Actiheart ) accelerometry for up to 7 days . Three outcome measures : minutes spent sedentary ( < 20 cpm ) ; in light ( LPA : ≥20 – 399 cpm ) and in moderate-to-vigorous activity ( MVPA : ≥400 cpm ) were derived . Average daily activity levels were calculated and then segmented across the day ( morning , afternoon and evening ) . MVPA was log-transformed . Two-level r and om intercept models were used to analyse associations between activity level and temporal and demographic factors . Results Children were active for 67 % ( mean 568.5 SD 79.5 minutes ) of their daily registered time on average , with 88 % of active time spent in LPA . All children met current UK guidelines of 180 minutes of daily activity . There were no differences in children ’s average daily levels of sedentary activity and LPA by temporal and demographic factors : differences did emerge when activity was segmented across the day . Sex differences were largest in the morning , with girls being more sedentary , spending fewer minutes in LPA and 18 % less time in MVPA than boys . Children were more sedentary and less active ( LPA and MVPA ) in the morning if they attended childcare full-time compared to part-time , and on weekend mornings compared to weekdays . The reverse was true for weekend afternoons and evenings . Children with more educated mothers were less active in the evenings . Children were less sedentary and did more MVPA on summer evenings compared to winter evenings . Conclusions Preschool-aged children meet current physical activity guidelines , but with the majority of their active time spent in LPA , investigation of the importance of activity intensity in younger children is needed . Activity levels over the day differed by demographic and temporal factors , highlighting the need to consider temporality in future interventions . Increasing girls ’ morning activity and providing opportunities for daytime activity in winter months may be worthwhile Background : The aim of this study was to examine in detail levels and patterns of physical activity in preschool children and the effects of gender and BMI on this activity . Methods : Two hundred and fifty-three children aged 5 y participating in the Copenhagen Prospect i ve Studies on Asthma in Childhood wore an accelerometer day and night over a 4-wk period . The main outcome measure was level of physical activity using the raw data . A secondary measure was time spent in moderate to vigorous physical activity ( MVPA ) . A Fourier series analysis was applied to study in detail patterns over time . Results : Activity profiles throughout the year were unique for each sex , with boys being overall more active than girls except for winter months . Preschool children also showed distinct patterns of physical activity during weekdays as compared with weekends and were most active during weekdays . Preschool children in the highest tertile of BMI had a flat yearly activity profile and tended to be less active as compared with those in the lowest tertile . Conclusion : Preschool children showed significant gender differences in physical activity , with distinct patterns throughout the year as well as between weekdays and weekends . A high BMI tended to be associated with lower levels of physical activity OBJECTIVE : To identify correlates of objective ly measured moderate and vigorous physical activity ( MVPA ) in children during preschool attendance . METHODS : This cross-sectional study included data from 426 apparently healthy Danish children ( 49.5 % boys ) , 5 to 6 years of age enrolled in 42 r and omly selected preschools . The percentage of time spent in MVPA ( ≥574 counts/15 second ) during preschool attendance was measured using ActiGraph accelerometers over 4.3 preschool days in May and June in 2009 . Thirty-seven potential correlates across the child , preschool staff , and preschool environment domains were tested for associations with MVPA . RESULTS : The final multivariate model identified 9 significant correlates of MVPA . Preterm birth , vegetation on the playground , and rainy days were negatively associated with MVPA , whereas child motor coordination , location of preschool building on the playground , gender ( boys ) , percentage afternoon hours , and size of indoor area per child were positively associated with MVPA . The direction of the significant association with the parental mean education level was unclear . CONCLUSIONS : We identified a number of new modifiable correlates  of MVPA  during preschool attendance . The positive association with size of indoor area per child and location of the preschool building on the playground seem important correlates to be targeted in future studies Early childhood is a critical time for promoting physical activity . Few studies have investigated the effect of interventions in this population . The aim of this study was to investigate the effect of a school-based active play intervention on preschool children 's sedentary time and physical activity .  Preschool children were recruited from r and omly selected preschools . Schools were r and omly assigned to an intervention or comparison group . One teacher per intervention school received training from active play professionals in the delivery of a 6-week active play programme . Comparison schools continued their usual practice . Children wore a  uni-axial accelerometer  for 7 days at baseline , immediately after and at 6-month post-intervention . No significant intervention effects were observed for sedentary time or physical activity . However , sex and hours spent at school were significant predictors of physical activity . Children who spent fewer hours ( half-day children ) at school were significantly more active than their full-day counterparts . Physical activity during the intervention classes was high even though neither daily physical activity nor sedentary time changed . Notably children who spent more time at preschool were less active suggesting that preschool was not as conducive to physical activity engagement as other environments Background Low levels of physical activity are characteristic in preschoolers . To effectively promote physical activity , it is necessary to underst and factors that influence young children 's physical activity . The present study aim ed to investigate how physical activity levels are influenced by environmental factors during recess in preschool . Methods Preschool playground observations and pedometry during recess were carried out in 39 r and omly selected preschools ( 415 boys and 368 girls ; 5.3 ± 0.4 years old ) . In order to examine the contribution of playground variables to physical activity levels , taking adjustment for clustering of subjects within preschools into account , multilevel analyses were conducted . Results During recess boys took significantly more steps per minute than girls ( 65 ± 36 versus 54 ± 28 steps/min ) . In both genders higher step counts per minute were significantly associated with less children per m2 and with shorter recess times . Only in boys a hard playground surface was a borderline significant predictor for higher physical activity levels . In girls higher step counts were associated with the presence of less supervising teachers . Playground markings , access to toys , the number of playing or aim ing equipment pieces and the presence of vegetation or height differences were not significant physical activity predictors in both genders . Conclusion In preschool children physical activity during outdoor play is associated with modifiable playground factors . Further study is recommended to evaluate if the provision of more play space , the promotion of continued activity by supervisors and the modification of playground characteristics can increase physical activity levels in preschoolers Background Early childhood provides a window of opportunity for the promotion of physical activity . Given the limited effectiveness of interventions to date , new approaches are needed . Socio-ecological models suggest that involving parents as intervention targets may be effective in fostering healthier lifestyles in children . This study describes the effectiveness of a family-focused ‘ Active Play ’ intervention in decreasing sedentary time and increasing total physical activity in preschool children . MethodS eventy-seven families were recruited from 8 r and omly selected SureStart children ’s centres in the North West of Engl and . Centres were r and omly assigned to either an intervention ( n = 4 ) or a comparison group ( n = 4 ) . Parents and children in the intervention group received a 10-week active play programme delivered by trained active play professionals ; this included an activity and educational component . Families in the comparison group were asked to maintain their usual routine . Each participating parent and child wore a  uni-axial accelerometer  for 7 days at baseline and post-test . Week and weekend day sedentary time and total physical activity adjusted for child- and home- level covariates were analysed using multilevel analyses . Results Significant intervention effects were observed for sedentary time and physical activity for both week and weekend days . Children in the intervention group engaged in 1.5 % and 4.3 % less sedentary time during week and weekend days , respectively and 4.5 % and 13.1 % more physical activity during week and weekend days , respectively than children in the comparison group . Parent ’s participation in sport and their physical activity levels , child ’s sex , availability of media in the home and attendance at organised activities were significant predictors of sedentary time and physical activity in this age group . Conclusion A 10-week family focused active play intervention produced positive changes in sedentary time and total physical activity levels in preschool children . Specific covariates were identified as having a significant effect on the outcome measures . Moreover , children whose parents were active engaged in less sedentary time and more physical activity suggesting that parent ’s activity habits are mediators of physical activity engagement in this age group OBJECTIVE To report dietary intake and physical activity among preschool-aged children living in rural American Indian communities before participation in a family-based healthy lifestyle intervention  and to compare data to current age-specific recommendations . SUBJECTS/ DESIGN One hundred thirty-five preschool-aged children , living in rural American Indian communities , provided diet and physical activity data before participating in a 2-year r and omized healthy lifestyle intervention .  Three 24-hour dietary recalls assessed nutrient and food and added sugar intake , which were compared to the National Academy of Science 's Dietary Reference Intakes , the US Department of Agriculture 's MyPyramid , and American Heart Association recommendations . Time watching television and moderate plus vigorous activity was compared to MyPyramid and American Academy of Pediatrics recommendations . STATISTICAL ANALYSIS Nutrient , food group , added sugar intake , and time watching television and in moderate or vigorous activity  were compared to recommendations by computing the percent of recommendations met . Nonparametric tests identified differences in diet and physical activity among age groups and normal and overweight children ( body mass index < 85th and > or = 85th percentile ) . RESULTS Average nutrient intakes met recommendations whereas food group intakes did not . Mean fruit and vegetable intakes for 2- to 3-year-olds were 0.36 c/day fruit and 0.45 c/day vegetables and , for 4- to 5-year-olds , 0.33 c/day fruit and 0.48 c/day vegetables . Both age groups reported consuming more than 50 g added sugar , exceeding the recommendation of 16 g. Overweight vs normal weight children reported significantly more sweetened beverage intake ( 8.0+/-0.10 vs 5.28+/-0.08 oz/day , P<0.01 ) . On average , all children reported watching television 2.0 hours/day and significant differences were observed for total television viewing and nonviewing time between overweight and normal weight children ( 8.52+/-0.6 vs 6.54+/-0.6 hours/day , P<0.01 ) . All children engaged in < 20 minutes/day of moderate or vigorous activity . CONCLUSIONS Overall , children in this sample did not meet MyPyramid recommendations for fruits or vegetables and exceed added sugar intake recommendations . Television viewing time and time when the television was on in the home was highly prevalent along with low levels of moderate or vigorous activity . The Healthy Children Strong Families intervention we studied has potential for improving nutrition and physical activity among preschool-aged children living in rural American Indian communities Alarm about the increasing prevalence of childhood obesity has focussed attention on individual lifestyle behaviours that may contribute to unhealthy weight . More distal predictors such as maternal employment may also be implicated since working mothers have less time to supervise children 's daily activities . The research reported here used two waves of data from the Longitudinal Study of Australian Children to investigate whether  mothers ' hours in paid work  shape young children 's  television viewing , snacking and physical activity , and through those lifestyle behaviours , children 's weight at ages 4 - 5 years and 6 - 7 years . At both ages , children 's lifestyle behaviours were interrelated and associated with weight status . Cross 
    Output:
    
agent
PA correlates/determinants were relatively consistent between objective and subjective PA measures .
A small number of demographic/biological and social/cultural factors were associated with PA .
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Asthma is a severe problem among inner city children , and recent evidence suggests that both allergen exposure and lifestyle can impact the disease early in childhood . This study was design ed to investigate the association between physical activity and wheezing among a population of inner city children enrolling in Head Start . The parents of children aged 3 - 5 years responded to a question naire ( N = 144 ) to determine the presence and severity of wheezing and asthma .  Information was also gathered regarding home environment , food frequency , and presence of other allergic diseases . Serum was obtained to measure total IgE and specific IgE levels to common allergens . Height and weight for body mass index were recorded . Lastly , motion sensor wristwatches ( Actiwatch ) were worn continuously by a subset of these children ( n = 54 ) for 6 or 7 days . Physical activity measured with the motion sensor was decreased among children with a history of wheezing . The significant differences involved those measures of activity relating to prolonged or sustained physical activity . The correlates of asthma associated with decreased levels of physical activity included : 1 ) a history of wheezing in the last 12 months , 2 ) the diagnosis of asthma , and 3 ) presentation to the emergency room in the last 12 months for wheezing or asthma . In a preschool-age population , decreased physical activity was observed among children with a history of asthma or wheezing . Decreased physical activity could contribute to persistence of asthma or put children at higher risk for obesity and other chronic diseases Background Little is known about preschool-aged children ’s levels of  physical activity ( PA ) over the course of the day . Using time-stamped data , we describe the levels and patterns of PA in a population -based sample of four-year-old British children . Methods Within the Southampton Women ’s Survey the PA levels of 593 4-year-old children ( 51 % female ) were measured using ( Actiheart ) accelerometry for up to 7 days . Three outcome measures : minutes spent sedentary ( < 20 cpm ) ; in light ( LPA : ≥20 – 399 cpm ) and in moderate-to-vigorous activity ( MVPA : ≥400 cpm ) were derived . Average daily activity levels were calculated and then segmented across the day ( morning , afternoon and evening ) . MVPA was log-transformed . Two-level r and om intercept models were used to analyse associations between activity level and temporal and demographic factors . Results Children were active for 67 % ( mean 568.5 SD 79.5 minutes ) of their daily registered time on average , with 88 % of active time spent in LPA . All children met current UK guidelines of 180 minutes of daily activity . There were no differences in children ’s average daily levels of sedentary activity and LPA by temporal and demographic factors : differences did emerge when activity was segmented across the day . Sex differences were largest in the morning , with girls being more sedentary , spending fewer minutes in LPA and 18 % less time in MVPA than boys . Children were more sedentary and less active ( LPA and MVPA ) in the morning if they attended childcare full-time compared to part-time , and on weekend mornings compared to weekdays . The reverse was true for weekend afternoons and evenings . Children with more educated mothers were less active in the evenings . Children were less sedentary and did more MVPA on summer evenings compared to winter evenings . Conclusions Preschool-aged children meet current physical activity guidelines , but with the majority of their active time spent in LPA , investigation of the importance of activity intensity in younger children is needed . Activity levels over the day differed by demographic and temporal factors , highlighting the need to consider temporality in future interventions . Increasing girls ’ morning activity and providing opportunities for daytime activity in winter months may be worthwhile Background : The aim of this study was to examine in detail levels and patterns of physical activity in preschool children and the effects of gender and BMI on this activity . Methods : Two hundred and fifty-three children aged 5 y participating in the Copenhagen Prospect i ve Studies on Asthma in Childhood wore an accelerometer day and night over a 4-wk period . The main outcome measure was level of physical activity using the raw data . A secondary measure was time spent in moderate to vigorous physical activity ( MVPA ) . A Fourier series analysis was applied to study in detail patterns over time . Results : Activity profiles throughout the year were unique for each sex , with boys being overall more active than girls except for winter months . Preschool children also showed distinct patterns of physical activity during weekdays as compared with weekends and were most active during weekdays . Preschool children in the highest tertile of BMI had a flat yearly activity profile and tended to be less active as compared with those in the lowest tertile . Conclusion : Preschool children showed significant gender differences in physical activity , with distinct patterns throughout the year as well as between weekdays and weekends . A high BMI tended to be associated with lower levels of physical activity OBJECTIVE : To identify correlates of objective ly measured moderate and vigorous physical activity ( MVPA ) in children during preschool attendance . METHODS : This cross-sectional study included data from 426 apparently healthy Danish children ( 49.5 % boys ) , 5 to 6 years of age enrolled in 42 r and omly selected preschools . The percentage of time spent in MVPA ( ≥574 counts/15 second ) during preschool attendance was measured using ActiGraph accelerometers over 4.3 preschool days in May and June in 2009 . Thirty-seven potential correlates across the child , preschool staff , and preschool environment domains were tested for associations with MVPA . RESULTS : The final multivariate model identified 9 significant correlates of MVPA . Preterm birth , vegetation on the playground , and rainy days were negatively associated with MVPA , whereas child motor coordination , location of preschool building on the playground , gender ( boys ) , percentage afternoon hours , and size of indoor area per child were positively associated with MVPA . The direction of the significant association with the parental mean education level was unclear . CONCLUSIONS : We identified a number of new modifiable correlates  of MVPA  during preschool attendance . The positive association with size of indoor area per child and location of the preschool building on the playground seem important correlates to be targeted in future studies Early childhood is a critical time for promoting physical activity . Few studies have investigated the effect of interventions in this population . The aim of this study was to investigate the effect of a school-based active play intervention on preschool children 's sedentary time and physical activity .  Preschool children were recruited from r and omly selected preschools . Schools were r and omly assigned to an intervention or comparison group . One teacher per intervention school received training from active play professionals in the delivery of a 6-week active play programme . Comparison schools continued their usual practice . Children wore a  uni-axial accelerometer  for 7 days at baseline , immediately after and at 6-month post-intervention . No significant intervention effects were observed for sedentary time or physical activity . However , sex and hours spent at school were significant predictors of physical activity . Children who spent fewer hours ( half-day children ) at school were significantly more active than their full-day counterparts . Physical activity during the intervention classes was high even though neither daily physical activity nor sedentary time changed . Notably children who spent more time at preschool were less active suggesting that preschool was not as conducive to physical activity engagement as other environments Background Low levels of physical activity are characteristic in preschoolers . To effectively promote physical activity , it is necessary to underst and factors that influence young children 's physical activity . The present study aim ed to investigate how physical activity levels are influenced by environmental factors during recess in preschool . Methods Preschool playground observations and pedometry during recess were carried out in 39 r and omly selected preschools ( 415 boys and 368 girls ; 5.3 ± 0.4 years old ) . In order to examine the contribution of playground variables to physical activity levels , taking adjustment for clustering of subjects within preschools into account , multilevel analyses were conducted . Results During recess boys took significantly more steps per minute than girls ( 65 ± 36 versus 54 ± 28 steps/min ) . In both genders higher step counts per minute were significantly associated with less children per m2 and with shorter recess times . Only in boys a hard playground surface was a borderline significant predictor for higher physical activity levels . In girls higher step counts were associated with the presence of less supervising teachers . Playground markings , access to toys , the number of playing or aim ing equipment pieces and the presence of vegetation or height differences were not significant physical activity predictors in both genders . Conclusion In preschool children physical activity during outdoor play is associated with modifiable playground factors . Further study is recommended to evaluate if the provision of more play space , the promotion of continued activity by supervisors and the modification of playground characteristics can increase physical activity levels in preschoolers Background Early childhood provides a window of opportunity for the promotion of physical activity . Given the limited effectiveness of interventions to date , new approaches are needed . Socio-ecological models suggest that involving parents as intervention targets may be effective in fostering healthier lifestyles in children . This study describes the effectiveness of a family-focused ‘ Active Play ’ intervention in decreasing sedentary time and increasing total physical activity in preschool children . MethodS eventy-seven families were recruited from 8 r and omly selected SureStart children ’s centres in the North West of Engl and . Centres were r and omly assigned to either an intervention ( n = 4 ) or a comparison group ( n = 4 ) . Parents and children in the intervention group received a 10-week active play programme delivered by trained active play professionals ; this included an activity and educational component . Families in the comparison group were asked to maintain their usual routine . Each participating parent and child wore a  uni-axial accelerometer  for 7 days at baseline and post-test . Week and weekend day sedentary time and total physical activity adjusted for child- and home- level covariates were analysed using multilevel analyses . Results Significant intervention effects were observed for sedentary time and physical activity for both week and weekend days . Children in the intervention group engaged in 1.5 % and 4.3 % less sedentary time during week and weekend days , respectively and 4.5 % and 13.1 % more physical activity during week and weekend days , respectively than children in the comparison group . Parent ’s participation in sport and their physical activity levels , child ’s sex , availability of media in the home and attendance at organised activities were significant predictors of sedentary time and physical activity in this age group . Conclusion A 10-week family focused active play intervention produced positive changes in sedentary time and total physical activity levels in preschool children . Specific covariates were identified as having a significant effect on the outcome measures . Moreover , children whose parents were active engaged in less sedentary time and more physical activity suggesting that parent ’s activity habits are mediators of physical activity engagement in this age group OBJECTIVE To report dietary intake and physical activity among preschool-aged children living in rural American Indian communities before participation in a family-based healthy lifestyle intervention  and to compare data to current age-specific recommendations . SUBJECTS/ DESIGN One hundred thirty-five preschool-aged children , living in rural American Indian communities , provided diet and physical activity data before participating in a 2-year r and omized healthy lifestyle intervention .  Three 24-hour dietary recalls assessed nutrient and food and added sugar intake , which were compared to the National Academy of Science 's Dietary Reference Intakes , the US Department of Agriculture 's MyPyramid , and American Heart Association recommendations . Time watching television and moderate plus vigorous activity was compared to MyPyramid and American Academy of Pediatrics recommendations . STATISTICAL ANALYSIS Nutrient , food group , added sugar intake , and time watching television and in moderate or vigorous activity  were compared to recommendations by computing the percent of recommendations met . Nonparametric tests identified differences in diet and physical activity among age groups and normal and overweight children ( body mass index < 85th and > or = 85th percentile ) . RESULTS Average nutrient intakes met recommendations whereas food group intakes did not . Mean fruit and vegetable intakes for 2- to 3-year-olds were 0.36 c/day fruit and 0.45 c/day vegetables and , for 4- to 5-year-olds , 0.33 c/day fruit and 0.48 c/day vegetables . Both age groups reported consuming more than 50 g added sugar , exceeding the recommendation of 16 g. Overweight vs normal weight children reported significantly more sweetened beverage intake ( 8.0+/-0.10 vs 5.28+/-0.08 oz/day , P<0.01 ) . On average , all children reported watching television 2.0 hours/day and significant differences were observed for total television viewing and nonviewing time between overweight and normal weight children ( 8.52+/-0.6 vs 6.54+/-0.6 hours/day , P<0.01 ) . All children engaged in < 20 minutes/day of moderate or vigorous activity . CONCLUSIONS Overall , children in this sample did not meet MyPyramid recommendations for fruits or vegetables and exceed added sugar intake recommendations . Television viewing time and time when the television was on in the home was highly prevalent along with low levels of moderate or vigorous activity . The Healthy Children Strong Families intervention we studied has potential for improving nutrition and physical activity among preschool-aged children living in rural American Indian communities Alarm about the increasing prevalence of childhood obesity has focussed attention on individual lifestyle behaviours that may contribute to unhealthy weight . More distal predictors such as maternal employment may also be implicated since working mothers have less time to supervise children 's daily activities . The research reported here used two waves of data from the Longitudinal Study of Australian Children to investigate whether  mothers ' hours in paid work  shape young children 's  television viewing , snacking and physical activity , and through those lifestyle behaviours , children 's weight at ages 4 - 5 years and 6 - 7 years . At both ages , children 's lifestyle behaviours were interrelated and associated with weight status . Cross 
    Output:
    