Daily physical activity,cardiorespiratory fitness,nutritional status,endothelial function,and autonomic modulation in school-age adolescents: A principal component analysis

PurposeThis study evaluated the association between cardiorespiratory fitness, abdominal obesity, blood pressure, endothelial function, and autonomic modulation in school-age adolescents exhibiting different levels of habitual physical activity and nutritional status, through a multivariate statistical approach.Methods101 adolescents aged 15–18 years (54 females) underwent assessments of daily physical activity, body mass index, cardiorespiratory fitness, reactive hyperemia, and heart rate variability. Based on BMI adjusted for age and sex (z-BMI), 21 adolescents were classified as ‘overweight’ (9 girls), and 9 as ‘obese’ (4 girls). The common variation between those variables was assessed through Principal Component Analysis (PCA).ResultsMain axis of common variation of outcomes analyzed defined four principal components (PCs) accounting for 69.7% of overall variance, related to ‘abdominal obesity and blood pressure’ (PC1; eigenvalue = 2.76), ‘cardiorespiratory fitness, endothelial function, and autonomic modulation’ (PC2, eigenvalue = 1.98), ‘cardiorespiratory fitness’ (PC3, eigenvalue = 1.21), and ‘sedentary behavior’ (PC4, eigenvalue = 1.02). Girls reported longer screen time and sedentary behavior than boys. Notwithstanding, in both sexes poorer cardiorespiratory fitness corresponded to lower reactive hyperemia and vagal modulation, irrespective of the nutritional status. Overall, adolescents classified as ‘obese’ and ‘sedentary’ exhibited poorer CRF concomitantly to autonomic and endothelial dysfunctions.ConclusionIn school-age adolescents, endothelial and autonomic dysfunctions related to poor cardiorespiratory fitness, irrespective of the nutritional status and physical activity level. However, endothelial and autonomic dysfunctions were more prevalent among adolescents combining poor cardiorespiratory fitness, reduced levels of daily physical activity, and overweight/obesity.     

Are eating habits associated with physical fitness in primary school children?

ObjectiveChildren's eating habits have mainly been related to anthropometric characteristics but less is known about their association with physical fitness.Methods278 French school children (131 boys and 147 girls) filled in eating habit questionnaires and completed anthropometric measurement (weight, height, skinfolds) and physical fitness tests. The 20-m Shuttle run test and the Squat Jump test were used to assess aerobic fitness and anaerobic (lower limb muscle power) fitness respectively.ResultsBreakfast consumption was associated with both aerobic fitness (p < 0.05) and lower limb muscle power (p < 0.01) while snacking was negatively related to Squat Jump performances (p < 0.05). There was no association between physical fitness and either the type of the consumed-beverages or TV watching during diner and lunch meals. Cumulated unhealthy eating habits was negatively associated with CRF stages and lower limb muscle power performances (p < 0.05).ConclusionFrench primary school children physical fitness is associated with their eating habits and decreases with the number of unhealthy eating behaviors cumulated.     

Weight status and weight-related behaviors of children commencing school

ObjectiveTo describe the weight status and weight-related behaviors of children commencing school.MethodsThis study is a representative cross-sectional survey of Australian children in their first year of schooling (n = 1141) in 2010. Height and weight were measured, and parents reported their child's diet, physical activity and screen-time.Results18.7% of children were overweight/obese. Compared with non-overweight/obese peers, overweight/obese boys were 1.73 times (95% CI 1.08, 2.79) as likely to exceed recommended screen time and 2.07 times (95% CI 1.11, 3.87) as likely to eat dinner three or more times/week in front of the TV. Overweight/obese girls were twice as likely to have a TV in their bedroom (OR 2.00, 95% CI 1.12, 3.59) and usually be rewarded with sweets for good behavior (OR 1.96, 95% CI 1.09, 3.51) and were 1.65 times as likely to be inactive (95% CI 1.08, 2.55).ConclusionWe showed that many children begin school with established weight-related behaviors that occur in the home environment. The inclusion of parents and the home environment in intervention strategies will be important to support changes to reduce childhood obesity. The weight status and weight-related behaviors of children entering school may potentially be a general indicator of the overall effectiveness of obesity prevention interventions among preschool-aged children.     

Overweight and obesity in Eastern Morocco: Prevalence and associated risk factors among high school students

BackgroundOverweight and obesity in children and adolescents have become a major public health problem affecting most countries worldwide. The purpose of the study was to assess the prevalence and risk factors of overweight and obesity among public high school students in Eastern Morocco.MethodsA cross-sectional survey was conducted between February and May 2014 among a sample of 2271 students (1086 girls and 1185 boys). References from the International Obesity Task Force (IOTF) were used to determine the prevalence of overweight and obesity.ResultsThe prevalence of overweight and obesity reached 12.2% (14.2% in girls vs 10.4% in boys, P < 0.01) and 3.0% (3.1% in girls vs 2.8% in boys), respectively. Risk factors associated with overweight and obesity were urban residence (OR = 1.76; [1.18–2.63]; P < 0.01), father's income ≥ 5000 MAD (OR = 1.32; [1.02–1.70]; P < 0.05), father's overweight (including obesity) (OR = 1.87; [1.38–2.54]; P < 0.001) and female sex (OR = 1.31; [1.02–1.68]; P < 0.05).ConclusionThe prevalence of overweight/obesity has reached an alarming rate among high school students in the Eastern region of Morocco. The findings of the present study suggest an urgent need to set up a strategy to prevent and combat this epidemic.     

Impact of diagnosis of overweight and obesity on weight management among hospitalized patients

BackgroundObesity is a growing epidemic associated with a 30% increase in general mortality. Despite this, diagnosis and treatment is still deficient. A large number of patients with overweight and obesity enter hospitals daily; therefore, the hospital setting could be used as a scenario for intervention in this population.ObjectivesTo determine the frequency of diagnosis and treatment of overweight/obesity in hospitalized patients and to identify the factors involved in the probability of offering a diagnosis and treatment.MethodsCross-sectional data from 316 patients aged 18 years and over admitted in the Department of Internal Medicine during 2016–2017 period. Logistic regression was used to estimate the relationship between the possible predictors and the diagnosis of overweight and/or obesity and the development of a treatment.ResultsOnly 10.8% of the population was diagnosed (overweight 2.6%, obesity 18.8%). Patients with a BMI >40 kg/m² had a greater probability of being diagnosed (OR = 1.87; 95% CI, 2.2–19.4; p = 0.001). Only 4.4% of the population received treatment (overweight 3.2%, obesity 5.6%) and the only factor that increased the probability of receiving treatment was having been diagnosed with overweight/obesity in the medical record (OR = 2.28; 95% CI, 2.31–41.94; p = 0.002).DiscussionDespite the high prevalence of overweight and obesity among hospitalized patients, there is no adequate diagnosis and treatment. Future research should be directed at strategies that increase medical recognition of overweight/obesity as well as identifying the long-term benefits of diagnosing overweight/obesity for the reduction and control of body weight.     

Association between habitual school travel and muscular fitness in youth

ObjectiveTo determine whether active school travel is associated with muscular fitness, which is an emerging marker of youth health.MethodsHandgrip strength, vertical jump and vertical jump peak power were measured in n = 6829 English schoolchildren (53% males, age 12.9 ± 1.2 years) between 2007 and 2011. Participants were grouped according to self-reported habitual school travel modality.ResultsCyclists had greater handgrip strength than passive travelers. Vertical jump height was greater in walkers and cyclists compared with passive travelers. Jump peak power was also higher in walkers than in the passive travel group. Compared with passive travelers, cyclists had a higher (age, sex and BMI-adjusted) likelihood of good handgrip strength (OR 1.42, 95%CI;1.14–1.76) and walkers were more likely to have good measures for vertical jump peak power (OR 1.14, 95%CI;1.00–1.29). Cyclists' likelihood of having good handgrip strength remained significantly higher when adjusted for physical activity (OR 1.29, 95%CI;1.08–1.46).ConclusionMuscular fitness differs according to school travel habits. Cycling is independently associated with better handgrip strength perhaps due to the physical demands of the activity. Better muscular fitness may provide another health-related reason to encourage active school travel.     

Influence of the social environment on children's school travel

ObjectivesTo analyze the association between parental perceptions of the social environment and walking and biking to school among 10–14-year-olds.MethodsSurveys were conducted with 432 parents of 10–14-year-olds in the San Francisco Bay Area during 2006 and 2007; the final sample size was 357. The social environment was measured with a 3-item scale assessing child-centered social control. Unadjusted and adjusted differences in rates of active travel to school were compared between families reporting high levels of social control in their neighborhood and those reporting low or neutral levels of social control. Adjusted differences were computed by matching respondents on child and household characteristics and distance to school.ResultsOf children whose parents reported high levels of social control, 37% walked or biked to school, compared with 24% of children whose parents reported low or neutral levels. The adjusted difference between the two groups was 10 percentage points (p = 0.04). The association was strongest for girls and non-Hispanic whites.ConclusionsHigher levels of parent-perceived child-centered social control are associated with more walking and biking to school. Increasing physical activity through active travel to school may require intervention programs to address the social environment.     

Associations between inhibitory control and body weight in German primary school children

Deficits in inhibitory control are supposed to be a risk factor for overweight but literature concerning childhood and beyond the clinical setting is scarce. The objective of this study was to investigate the role of inhibitory control in regards to body weight in a large non-clinical sample of primary school children. Baseline data of 498 children (1st and 2nd grade; 7.0 ± 0.6 years; 49.8% boys) participating in a school-based intervention study in Germany were used. Children performed a Go-Nogo-task to assess inhibitory control. Height and weight were collected and converted to BMI percentiles based on national standards. Relevant influencing factors (sociodemographic data, health characteristics of parents, children's health behaviour) were assessed via parental questionnaire. Inhibitory control was significantly associated with body weight and contributed to the statistical prediction of body weight above and beyond parent education, migration background, parent weight, TV consumption and breakfast habits. Moreover, obese children displayed significantly lower inhibitory control compared to non-overweight and overweight children. The findings suggest that deficits in inhibitory control constitute a risk factor for paediatric obesity.     

A longitudinal study of the distance that young people walk to school

Walking or cycling to school has been associated with important health benefits. Distance between home and school is the main correlate of active commuting to school, but how far children walk to school and how this changes as children age is unknown. Mode of commuting and objectively-assessed distance to school were measured at 3 time points: aged 9/10 years, 10/11 years and 13/14 years. Data were analysed using ROC-curve analyses. With age, children walked further to school; the threshold distance that best discriminated walkers from passive commuters was 1421 m in 10-year-olds, 1627 m in 11-year-olds and 3046 m in 14-year-olds. Future interventions should consider the distance that young people actually walk.     

Association between unmet dental needs and school absenteeism because of illness or injury among U.S. school children and adolescents aged 6–17 years, 2011–2012

BackgroundWe assessed the prevalence of dental disease among U.S. children and adolescents aged 6–17 years, as well as the impact of unmet dental needs on school absenteeism because of illness/injury within the past 12 months.MethodsData were from the 2011/2012 National Survey of Children's Health (n = 65,680). Unmet dental need was defined as lack of access to appropriate and timely preventive or therapeutic dental healthcare when needed within the past 12 months. The impact of unmet dental needs on school absenteeism was measured using a multivariate generalized linear model with Poisson probability distribution (p < 0.05).ResultsWithin the past 12 months, 21.8% (10.8 million) of all U.S. children and adolescents aged 6–17 years had “a toothache, decayed teeth, or unfilled cavities.” Of all U.S. children and adolescents aged 6–17 years, 15.8% (7.8 million) reported any unmet dental need (i.e., preventive and/or therapeutic dental need) within the past 12 months. The mean number of days of school absence because of illness/injury was higher among students with an unmet therapeutic dental need in the presence of a dental condition compared to those reporting no unmet dental need (β = 0.25; p < 0.001).ConclusionsEnhanced and sustained efforts are needed to increase access to dental services among underserved U.S. children and adolescents.     

Establishing school day pedometer step count cut-points using ROC curves in low-income children

Previous research has not established pedometer step count cut-points that discriminate children that meet school day physical activity recommendations using a tri-axial ActiGraph accelerometer criterion. The purpose of this study was to determine step count cut-points that associate with 30 min of school day moderate-to-vigorous physical activity (MVPA) in school-aged children. Participants included 1053 school-aged children (mean age = 8.4 ± 1.8 years) recruited from three low-income schools from the state of Utah in the U.S. Physical activity was assessed using Yamax DigiWalker CW600 pedometers and ActiGraph wGT3X-BT triaxial accelerometers that were concurrently worn during school hours. Data were collected at each school during the 2014–2015 school year. Receiver operating characteristic (ROC) curves were used to determine pedometer step count cut-points that associated with at least 30 min of MVPA during school hours. Cut-points were determined using the maximum Youden's J statistic (J max). For the total sample, the area-under-the-curve (AUC) was 0.77 (p < 0.001) with a pedometer cut-point of 5505 steps (J max = 0.46, Sensitivity = 63%, Specificity = 84%; Accuracy = 76%). Step counts showed greater diagnostic ability in girls (AUC = 0.81, p < 0.001; Cut-point = 5306 steps; Accuracy = 78.8%) compared to boys (AUC = 0.72, p < 0.01; Cut-point = 5786 steps; Accuracy = 71.4%). Pedometer step counts showed good diagnostic ability in girls and fair diagnostic ability in boys for discriminating children that met at least 30 min of MVPA during school hours.     

Twenty-four hour dietary recalls by fourth-grade children were not influenced by observations of school meals

ObjectiveTo investigate whether school-meal observations influenced children's 24-hour dietary recalls.Study Design and SettingOver three school years, 555 randomly selected fourth-grade children were interviewed to obtain a 24-hour dietary recall; before being interviewed, 374 children were observed eating two school meals (breakfast, lunch), and 181 children were not observed. Within observation-status groups (observed, unobserved), children were randomized within sex to one of six combinations from two target periods (prior 24 hours, previous day) crossed with three interview times (morning, afternoon, evening).ResultsFor each of the five variables (interview length, meals/snacks, meal components, items, kilocalories), naïve and adjusted equivalence tests rejected that observation-status groups were different, indicating that school-meal observations did not influence children's 24-hour dietary recalls. There was a target-period effect on length (P < 0.0001) (longer for prior-24-hour recalls), a school year effect on length (P = 0.0002) (longer for third year), and a target period–interview time interaction on items (P = 0.0110) and kilocalories (P = 0.0047) (both smaller for previous-day recalls in the afternoon than prior-24-hour recalls in the afternoon and previous-day recalls in the evening), indicating that variables were sufficiently sensitive and psychometrically reliable.ConclusionConclusions about 24-hour dietary recalls by fourth-grade children observed eating school meals in validation studies are generalizable to 24-hour dietary recalls by comparable but unobserved children in nonvalidation studies.     

Objectively assessed physical activity,fitness and subjective wellbeing

BackgroundThe existing evidence for a cross-sectional association between physical activity and subjective wellbeing is inconsistent, mainly because of the reliance on self reported physical activity, which might have conceptual overlap with subjective health.PurposeTo examine associations of objectively assessed physical activity and cardiorespiratory fitness with subjective wellbeing.MethodsA sub-sample of participants (921 men and women, mean age 44.6 ± 15.0 yrs, 46.4% men) from the 2008 Health Survey for England completed objective measures of physical activity (Actigraph) and an 8 min sub-maximal step test to estimate levels of cardiorespiratory fitness. The General Health Questionnaire and self-rated health was used as indicators of subjective wellbeing.ResultsThe recorded levels of moderate to vigorous physical activity (MVPA) were higher in participants reporting very good health (adjusted mean difference = 6.7, 95% CI, 1.1–12.4 min/d, p = 0.019) compared with participants reporting fair–poor health after adjustment for various confounders and fitness level. Neither physical fitness, objectively assessed sedentary time or light activity was related to self-rated health. There was also no association between objectively measured physical activity and fitness with psychological health, despite a robust association with self reported MVPA in the overall sample.ConclusionsObjectively assessed MVPA is independently associated with self-rated health. Self reported, but not objectively assessed MVPA, was associated with psychological health. The null findings with regards to psychological health might partly reflect selection biases associated with the healthy nature of this sub-sample of participants.     

Risk factors for overweight and obesity in French adolescents: Physical activity,sedentary behavior and parental characteristics

ObjectiveWe determined the prevalence by age and sex and associated factors of overweight and obesity in French adolescents.MethodsWe conducted a cross-sectional study of 2385 adolescents aged 11–18 y (1213 boys and 1172 girls) from middle and high schools in the Aquitaine region (southwest France) in 2004–2005. Weight and height were measured, and adolescents filled in a questionnaire about their characteristics and those of their parents. Overweight and obesity were defined according to the age- and sex-specific body mass index cutoff points of the International Obesity Task force.ResultsPrevalence of overweight (obesity included) was greater in boys and younger children. The odds ratio (OR) for an adolescent being overweight increased with parents' being overweight (at least one parent overweight, OR 1.97, 1.48–2.62, P < 0.0001), low paternal socioeconomic status (OR 1.78, 1.22–2.60, P < 0.01) and sedentary behavior (22 h/wk, OR 1.33, 1.02–1.74, P < 0.05), and decreased with physical activity of parents (at least one parent active, OR 0.67, 0.51–0.89, P = 0.01).ConclusionOur data support the hypothesis that parental overweight and low socioeconomic status and adolescents' sedentary behavior are strong risk factors for adolescent overweight and obesity, and that parents active lifestyle is associated with a lower risk of overweight in their adolescents.     

Sustained Active Transportation is associated with a favorable body mass index trajectory across the early school years: Findings from the Quebec Longitudinal Study of Child Development birth cohort

ObjectiveTo determine the extent to which active transportation (AT) to and from school is associated with changes in body mass index (BMI) from kindergarten (6-year-olds) through grade 2 (8-year-olds).MethodsThe sample included 1170 children (50.4% of baseline participants) who were part of the Quebec Longitudinal Study of Child Development (QLSCD), a birth cohort established in 1998 in Quebec, Canada. Data were collected by trained interviewers using structured interviews and measuring height and weight in the home with the person most knowledgeable about the child's health. Relative weight was operationalized as age- and sex-adjusted BMI Z-scores.ResultsGrowth curve analyses showed that using AT to and from school both when in kindergarten and in grade 1 was predictive of a lower BMI Z-score (coeff = - 0.18, SE = 0.09, p = 0.05) in grade 1. Using AT to and from school in kindergarten, grade 1, and grade 2 was predictive of a lower BMI Z-score (coeff = - 0.30, SE = 0.098, p = 0.003) in grade 2. No other covariates were predictive of relative weight across time, although having an overweight or obese mother was associated with a BMI Z-score of 0.39 (SE = 0.07, p < 0.001) across all time points.ConclusionSustained AT is associated with more healthful trajectories of BMI across the early school years.     

25-Hydroxyvitamin D and Cardiorespiratory Fitness in Prepubertal Overweight and Obese Children

Childhood obesity has become a major global health problem. Vitamin D deficiency and poor cardiorespiratory fitness are highly prevalent in children with overweight or obesity, but little is known about their relationships. In this study, we aimed to analyze the relationship between serum 25-hydroxyvitamin D (25(OH)D) and cardiorespiratory fitness parameters in prepubertal obese and overweight children. A cross-sectional design with a sample of 57 prepubertal children, aged 9–11 years, with overweight or obesity was used. The fasting concentration of 25(OH)D was analyzed with a chemiluminescent microparticle immunoassay. Fat and lean body masses were determined by using DXA. Maximal oxygen uptake (VO_2max) was measured with the maximal treadmill test. A total of 68.4% of the sample had sufficient levels of 25(OH)D. As expected, their cardiorespiratory fitness was poor compared with that of normal-weight children, but 60% of the group exceeded the median obesity-specific reference values. No differences were found between the sexes for relative VO_2max or 25(OH)D levels. Moreover, no correlations were found between 25(OH)D and body composition or cardiorespiratory parameters for sex or vitamin D groups. Vitamin D status seems not to be directly related to body composition or cardiorespiratory fitness in prepubertal overweight or obese children.     

Insufficient sleep among elementary and middle school students is linked with elevated soda consumption and other unhealthy dietary behaviors

ObjectiveThis study examines the extent to which insufficient sleep is associated with diet quality in students taking part in the Massachusetts Childhood Obesity Research Demonstration Project.MethodsData were collected in Fall 2012 for all 4th and 7th grade children enrolled in public schools in two Massachusetts communities. During annual body mass index (BMI) screening, students completed a survey that assessed diet, physical activity, screen time, and sleep. Of the 2456 enrolled students, 1870 (76%) had complete survey data. Generalized estimating equations were used to examine associations between sleep duration and dietary outcomes (vegetables, fruits, 100% juice, juice drinks, soda, sugar-sweetened beverages and water), accounting for clustering by school. Models were adjusted for community, grade, race/ethnicity, gender, television in the bedroom, screen time, and physical activity.ResultsIn adjusted models, students who reported sleeping < 10 hours/day consumed soda more frequently (β = 0.11, 95% CI: 0.03, 0.20) and vegetables less frequently (β = − 0.09, 95% CI: − 0.18, − 0.01) compared with students who reported ≥ 10 hours/day. No significant associations were observed between sleep duration and fruits, 100% juice, juice drinks or water.ConclusionsIn this population, insufficient sleep duration was associated with more frequent soda and less frequent vegetable consumption. Longitudinal research is needed to further examine these relationships.     

Tobacco outlet density near home and school: Associations with smoking and norms among US teens

This study examined whether living or going to school in neighborhoods with higher tobacco outlet density is associated with higher odds of cigarette smoking among teens, and with perceptions of greater smoking prevalence and peer approval. Using an Internet panel that is representative of US households, we matched data from teen-parent pairs (n = 2771, surveyed June 2011–December 2012) with environmental data about home and school neighborhoods. Density was measured as the number of tobacco outlets per square mile for a ½-mile roadway service area around each participant's home and school. Logistic regressions tested relationships between tobacco outlet density near home and schools with ever smoking. Linear regressions tested relationships between density, perceived prevalence and peer approval. Models were adjusted for teen, parent/household and neighborhood characteristics. In total, 41.0% of US teens (ages 13–16) lived within ½ mile of a tobacco outlet, and 44.4% attended school within 1000 ft of a tobacco outlet. Higher tobacco outlet density near home was associated with higher odds of ever smoking, although the relationship was small, OR = 1.01, 95% CI (1.00, 1.02). Higher tobacco outlet density near home was also associated with perceptions that more adults smoked, coef. = 0.09, 95% CI (0.01, 0.17). Higher tobacco outlet density near schools was not associated with any outcomes. Living in neighborhoods with higher tobacco outlet density may contribute to teen smoking by increasing access to tobacco products and by cultivating perceptions that smoking is more prevalent. Policy interventions to restrict tobacco outlet density should not be limited to school environments.     

The school effect on children's school time physical activity: The PEACH Project

ObjectiveThe school-setting is a potentially important environment for influencing children's physical activity. However limited research has focused on whether children's school-time physical activity is associated with the school they attend. This paper investigates the school effect on children's physical activity.MethodParticipants were 1307 pupils aged 10–11 years recruited from 23 primary schools in Bristol, UK during 2006–2008. Multilevel modelling (MLM) (MLwin 2.02) was used to asses between school differences in children's physical activity, measured using accelerometry (ActiGraph GT1M), adjusting for both individual and school variables.ResultsA significant school effect (p = 0.001) was found accounting for 14.5% of the total variance in physical activity. Boys were significantly more active than girls (p < 0.001), and the school attended accounted for a greater proportion of variance in boys' physical activity than girls' (23.4% vs. 12.2%). Seasonal variation and economic deprivation of the school neighbourhood were both significantly associated with children's school-time activity.ConclusionThis paper highlights a significant school effect on children's physical activity providing evidence that the school attended should be accounted for in future analysis and supporting the use of MLM in this field. Further investigation is required to explain the differences in physical activity found between schools.