Physical activity and cardiovascular risk factors in children: meta-analysis of randomized clinical trials

Physical activity and sedentary behavior thresholds for identifying childhood hypertension and its phenotypes: The Healthy Growth Study

Hypertension phenotypes may represent differential pathophysiologic mechanisms and clinical impact, yet they have been poorly investigated. The study aimed to examine the associations of physical activity and sedentary behavior with hypertension phenotypes in a large group of Greek children and to identify thresholds regarding risk of hypertension. This was a cross-sectional study with a regionally representative sample of 2473 schoolchildren aged 9-13 years, with full data on physical activity and sedentary behavior indices, as well as arterial blood pressure measurements, physical examination, and anthropometry. Hypertensive children of both sexes had lower levels of physical activity (steps/d). Hypertensive girls had lower moderate-to-vigorous physical activity (MVPA), whereas hypertensive boys with isolated systolic hypertension (ISH) had more screen time than their normotensive counterparts. Increased levels of physical activity was associated with 33%-54% lower risk of all hypertension phenotypes in both sexes, whereas increased MVPA was associated with 41%-65% lower risk of all phenotypes in girls and with ISH and systolic and diastolic hypertension (SDH) in boys. In boys, higher sedentary time was associated with 11%-13% higher risk for SDH and ISH. Cutoff points of 12,378 steps/d, 47.3 min/d of MVPA, and 2.9 h/d of sedentary behavior were determined for identifying children at increased risk of hypertension. Physical activity is inversely associated with all hypertension phenotypes, whereas sedentary behavior is positively associated with ISH and SDH in boys. More studies should confirm the hypertension-specific cutoff values identified to be used in future prevention programs for childhood hypertension.

The 2017 Dutch Physical Activity Guidelines

Background

The objective of this study was to derive evidence-based physical activity guidelines for the general Dutch population.

Methods

Two systematic reviews were conducted of English language meta-analyses in PubMed summarizing separately randomized controlled trials and prospective cohort studies on the relation between physical activity and sedentary behaviour on the one hand and the risk of all-cause mortality and incidence of 15 major chronic diseases and conditions on the other hand. Other outcome measures were risk factors for cardiovascular disease and type 2 diabetes, physical functioning, and fitness. On the basis of these reviews, an expert committee derived physical activity guidelines. In deriving the guidelines, the committee first selected only experimental and observational prospective findings with a strong level of evidence and then integrated both lines of evidence.

Results

The evidence found for beneficial effects on a large number of the outcome measures was sufficiently strong to draw up guidelines to increase physical activity and reduce sedentary behaviour, respectively. At the same time, the current evidence did not provide a sufficient basis for quantifying how much physical activity is minimally needed to achieve beneficial health effects, or at what amount sedentary behaviour becomes detrimental. A general tenet was that at every level of current activity, further increases in physical activity provide additional health benefits, with relatively larger effects among those who are currently not active or active only at light intensity. Three specific guidelines on (1) moderate- and vigorous-intensity physical activity, (2) bone- and muscle-strengthening activities, and (3) sedentary behaviour were formulated separately for adults and children.

Conclusions

There is an unabated need for evidence-based physical activity guidelines that can guide public health policies. Research in which physical activity is measured both objectively (quantity) and subjectively (type and quality) is needed to provide better estimates of the type and actual amount of physical activity required for health.

Electronic supplementary material

The online version of this article (10.1186/s12966-018-0661-9) contains supplementary material, which is available to authorized users.

"FIFA 11 for Health" for Europe in the Faroe Islands: Effects on health markers and physical fitness in 10- to 12-year-old schoolchildren

We evaluated effects of the school-based intervention "FIFA 11 for Health" for Europe on health and fitness profile in 10- to 12-year-old Faroese schoolchildren. 392 fifth-grade children were randomized into a control group (CG: n = 100, 11.1 ± 0.3 years, 149.0 ± 6.7 cm, 42.4 ± 10.2 kg) and an intervention group (IG: n = 292, 11.1 ± 0.3 years, 150.6 ± 6.9 cm, 44.2 ± 9.4 kg). IG underwent an 11-week intervention in which 2 weekly sessions of 45 minutes were included in the school curriculum focusing on health aspects, football skills, and 3v3 small-sided games. CG continued with their regular activities. Body composition, blood pressure, and resting heart rate, as well as Yo-Yo intermittent recovery children's test (YYIR1C) performance, horizontal jumping ability and postural balance were assessed pre and post intervention. Systolic blood pressure decreased more (-2.8 ± 9.9 vs 2.9 ± 8.4 mm Hg, P < .05) in IG than in CG. Lean body mass (1.0 ± 1.7 vs 0.7 ± 1.6 kg), postural balance (0.3 ± 3.9 vs -1.2 ± 5.9 seconds) and horizontal jump performance (5 ± 9 vs -5 ± 10 cm) increased more (P < .05) in IG than in CG. YYIR1C performance improved in CG (17%, 625 ± 423 to 730 ± 565 m) and IG (18%, 689 ± 412 vs 813 ± 391 m), but without between-group differences. A within-group decrease from 23.1 ± 8.4 to 22.5 ± 8.3% (P < .05) was observed in body fat percentage in IG only. In conclusion, the "FIFA 11 for Health" for Europe program had beneficial effects on SBP, body composition, jump performance and postural balance in 10- to 12-year-old Faroese schoolchildren, supporting the notion that school-based football interventions can facilitate health of children in a small-scale society and serve as an early step in the prevention of non-communicable diseases.

Effects of Before-School Physical Activity on Obesity Prevention and Wellness

INTRODUCTION

The effects of Build Our Kids Success-a 12-week, 1-hour before-school physical activity program-on BMI and social-emotional wellness among kindergarten to eighth grade students was examined.

STUDY DESIGN

This was a nonrandomized trial.

SETTING/PARTICIPANTS

Participants were from 24 schools in Massachusetts; there were 707 children from kindergarten to eighth grade.

INTERVENTION

Children registered for Build Our Kids Success in 2015-2016 participated in a 2 days/week or 3 days/week program. Nonparticipating children served as controls.

MAIN OUTCOME MEASURES

At baseline and 12 weeks, study staff measured children's heights/weights; children aged ≥8 years completed surveys. Main outcomes were 12-week change in BMI z-score, odds of a lower BMI category at follow-up, and child report of social-emotional wellness. Analyses were completed in March-June 2017.

RESULTS

Follow-up BMI was obtained from 67% of children and self-reported surveys from 72% of age-eligible children. Children in the 3 days/week group had improvements in BMI z-score (-0.22, 95% CI= -0.31, -0.14) and this mean change was significantly different than the comparison group (-0.17 difference, 95% CI= -0.27, -0.07). Children in the 3 days/week group also had higher odds of being in a lower BMI category at follow-up (OR=1.35, 95% CI=1.12, 1.62); significantly different than the comparison group (p<0.01). Children in the 2 days/week program had no significant changes in BMI outcomes. Children in the 3 days/week group demonstrated improvement in their student engagement scores (0.79 units, p=0.05) and had nonsignificant improvements in reported peer relationships, affect, and life satisfaction versus comparison. The 2 days/week group had significant improvements in positive affect and vitality/energy versus comparison.

CONCLUSIONS

A 3 days/week before-school physical activity program resulted in improved BMI and prevented increases in child obesity. Both Build Our Kids Success groups had improved social-emotional wellness versus controls.

TRIAL REGISTRATION

This study is registered at www.clinicaltrials.gov NCT03190135.

Physically Active Lessons Improve Lesson Activity and On-Task Behavior: A Cluster-Randomized Controlled Trial of the "Virtual Traveller" Intervention

BACKGROUND

Physically active lessons have not often been assessed with randomized controlled trials.

AIMS

Evaluate the effects of the "Virtual Traveller" (VT) intervention delivered using classroom interactive whiteboards on physical activity, on-task behavior, and student engagement.

METHODS

Participants were 219 children aged 8 to 9 years from 10 schools in Greater London, assessed in a cluster-randomized controlled trial between March 2015 and May 2016. For 6 weeks, intervention children received 10-minute VT sessions three times a week during math and English lessons (VT group: n = 113). Children in control schools received regular teaching (COM group: n = 106). Outcomes were school-day, weekend-day, and lesson-time sedentary behavior (SB), light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA), and on-task behavior and student engagement, assessed at baseline (T0), 2 weeks (T1), and 4 weeks (T2) during the VT intervention and 1 week (T3) and 3 months (T4) postintervention using multilevel modeling.

RESULTS

VT pupils engaged in significantly more school-day MVPA at T1 only, with no other significant differences between groups in overall school-day or weekend-day activity. VT pupils engaged in significantly less SB and more MVPA during lesson time than COM pupils. More on-task behavior was shown in VT pupils than COM pupils but there was no difference in student engagement.

DISCUSSION

VT reduced sedentary behavior and increased physical activity during lesson time but not across overall school or weekend days. VT improved on-task behavior but had no effect on student engagement.

CONCLUSION

Physical activity can be integrated into teaching using interactive whiteboards with no detriment to educational outcomes.

Active Learning Increases Children's Physical Activity across Demographic Subgroups

Purpose

Given the need to find more opportunities for physical activity within the elementary school day, this study was designed to asses the impact of I-CAN!, active lessons on: 1) student physical activity (PA) outcomes via accelerometry; and 2) socioeconomic status (SES), race, sex, body mass index (BMI), or fitness as moderators of this impact.

Methods

Participants were 2,493 fourth grade students (45.9% male, 45.8% white, 21.7% low SES) from 28 central Texas elementary schools randomly assigned to intervention (n=19) or control (n=9). Multilevel regression models evaluated the effect of I-CAN! on PA and effect sizes were calculated. The moderating effects of SES, race, sex, BMI, and fitness were examined in separate models.

Results

Students in treatment schools took significantly more steps than those in control schools (β = 125.267, SE = 41.327, p = .002, d = .44). I-CAN! had a significant effect on MVPA with treatment schools realizing 80% (β = 0.796, SE =0.251, p = .001; d = .38) more MVPA than the control schools. There were no significant school-level differences on sedentary behavior (β = -0.177, SE = 0.824, p = .83). SES, race, sex, BMI, and fitness level did not moderate the impact of active learning on step count and MVPA.

Conclusion

Active learning increases PA within elementary students, and does so consistently across demographic sub-groups. This is important as these sub-groups represent harder to reach populations for PA interventions. While these lessons may not be enough to help children reach daily recommendations of PA, they can supplement other opportunities for PA. This speaks to the potential of schools to adopt policy change to require active learning.

Exercise and adiposity in overweight and obese children and adolescents: protocol for a systematic review and network meta-analysis of randomised trials

INTRODUCTION

Overweight and obesity is a worldwide public health problem among children and adolescents. However, the magnitude of effect, as well as hierarchy of exercise interventions (aerobic, strength training or both), on selected measures of adiposity is not well established despite numerous trials on this issue. The primary purposes of this study are to use the network meta-analytical approach to determine the effects and hierarchy of exercise interventions on selected measures of adiposity in overweight and obese children and adolescents.

METHODS AND ANALYSIS

Randomised exercise intervention trials >4 weeks, available in any language up to 31 August 2017 and which include direct and/or indirect evidence, will be included. Studies will be located by searching seven electronic databases, cross-referencing and expert review. Dual selection and abstraction of data will occur. The primary outcomes will be changes in body mass index (in kg/m²), fat mass and percent body fat. Risk of bias will be assessed using the Cochrane Risk of Bias assessment instrument while confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation instrument for network meta-analysis. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of exercise treatments (aerobic, strength or both).

ETHICS AND DISSEMINATION

This study does not require ethics approval. Findings will be presented at a professional conference and published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD 42017073103 .

A longitudinal study of the associations of children's body mass index and physical activity with blood pressure

Childhood blood pressure is a marker of cardiovascular disease risk in later life. We examined how body mass index (BMI) and physical activity, and changes in these, are associated with blood pressure in primary school-aged children. Data are from 1223 children aged 9 years (Year 4) in Bristol, UK, 685 of whom had been assessed at 6 years (Year 1). Child height and weight were measured, and children wore accelerometers for five days, from which average counts per minute, and moderate-to-vigorous-intensity physical activity and sedentary minutes per day were derived. At age 9 years, blood pressure was measured. Multiple imputation of missing data and adjusted linear regression models were used to examine associations. Child BMI at 9 years was cross-sectionally associated with higher systolic (SBP) and diastolic (DBP) blood pressure (mean difference [95% CI]: 1.10 [0.34, 1.87] mmHg and 0.86 [0.13, 1.60] mmHg, respectively, per SD of BMI). Prospective associations of BMI at age 6 with blood pressure at age 9 were consistent with these cross-sectional associations. However, change in BMI between 6 and 9 years was not strongly associated with subsequent SBP or DBP (0.68 [-0.61, 1.98] mmHg and 1.23 [-0.09, 2.54] mmHg, respectively). There was little evidence that physical activity or sedentary time were associated with blood pressure in either cross-sectional or prospective analyses. Greater childhood BMI is associated with higher blood pressure, and this association persists over several years. Prevention of excessive bodyweight from early childhood may be important in stemming the development of cardiovascular risk.

Attainment of '5-2-1-0' obesity recommendations in preschool-aged children

Obesity prevention guidelines recommend children eat ≥ 5 servings of fruits and vegetables, view ≤ 2 h of screen time, participate in 1 h of physical activity, and consume 0 sugar-sweetened beverages daily, commonly known as '5-2-1-0'. We sought to determine: the extent to which preschool-aged children attending child care meet these guidelines, predictors of attainment, and associations of attainment with weight status. We analyzed in 2016, 24-hour dietary, physical activity, and screen time data collected in 2009-10 from 398 preschool-aged children in 30 child-care centers in Cincinnati, OH. Dietary intake, screen time and body-mass index (BMI) were obtained by research staff during child care and from parents when at home. Accelerometers measured physical activity. Mixed-effects models and generalized estimating equations were used to determine associations between '5-2-1-0' recommendations, demographic variables, and BMI z-scores. Average child age was 4.3 ± 0.7 years; 26% had a BMI ≥ 85th percentile. Seventeen percent of children with complete dietary data (n = 307) consumed ≥ 5 servings of fruits and vegetables and 50% consumed 0 sugar-sweetened beverages. < 1% with complete physical activity data (n = 386) met the activity recommendation; 81% of children (n = 379) had ≤ 2 h of screen time. Only 1 child met all of the '5-2-1-0' recommendations. There were no consistent demographic predictors of attaining individual recommendations. An additional hour of screen time was associated with a 0.11 (SD 0.06) increase in BMI z-score. Our data suggests there is ample room to increase fruit and vegetable intake and physical activity in preschool-aged children.

Factors That Influence Blood Pressure in 3- to 5-Year-Old Children: A Pilot Study

While incident elevations in blood pressure (BP) are apparent in preschool years, factors influencing BP in this population have received little attention. The purposes of this pilot study were to determine the feasibility of collecting data from preschoolers and their mothers and to determine effect sizes of relationships between BP and sex, race, birth status, body mass index (BMI), waist circumference (WC), geographic location, serum C-reactive protein (CRP), and salivary cortisol (morning, afternoon). A hypothesis-generating correlational design was used; 56 children, aged 3–5 years, were enrolled from six rural and urban Head Start programs in a southeastern state. On Day 1 of data collection, mothers completed demographic questionnaires and children had blood drawn by finger stick. On Day 2, children gave saliva samples for cortisol, were measured for height by stadiometer, weight by digital scales, and WC by tape measure and had their BP measured by Dinamap. Incident elevations in BP were found in 30% of children (17/56), the majority of which were of systolic BP; 65% of those with elevations were of normal weight. Data collection was feasible with few problems. Small-to-medium effect sizes were noted for BP status (normal, prehypertensive, and hypertensive) and cortisol p.m. and birth status (parent-reported prematurity or term); small effect sizes were seen for BP status and BMI, race, sex, and geographic location. CRP and cortisol had medium- and small-to-medium effect sizes, respectively, with diastolic blood pressure. Studies with larger, more diverse samples need to be conducted to test hypotheses posited from these estimated effect sizes.

The effects of a low-dose physical activity intervention on physical activity and body mass index in severely obese adolescents

Background While severe obesity in childhood poses the greatest long-term health risks, access to treatment is a common barrier. The present pilot study examined the effect of a 7-week low-dose physical activity (PA) intervention on PA and body mass index (BMI) in severe obese adolescents delivered via telephone and mail. Methods Adolescents (n = 64) receiving care from a pediatric obesity medical clinic were randomized to a control (n = 30) or intervention (n = 34) group. Height and weight were measured and BMI z-scores were calculated. PA was assessed by a pedometer. All measurements were completed pre- and post-intervention. The intervention group received weekly newsletters and telephone calls discussing various PA topics based on motivational interviewing for 7 weeks. The control group received no contact. A series of 2 × 2 (group by time) repeated measures analysis of covariances (ANCOVAs) adjusting for length of time between visits were performed to examine the effect of the intervention on PA and BMI z-scores. Results The majority of adolescents were severely obese (77%, BMI: > 99th percentile). Intention-to-treat analysis revealed intervention effects were not observed for either pedometer steps or BMI z-score (p > 0.05). Among those with complete data, adolescents who successfully changed their BMI z-score had larger BMI z-score changes than those who did not change their BMI z-score (p = 0.0001). This improvement was due to something other than PA as the change in BMI z-score was similar among those who did and did not successfully increase PA levels (p > 0.05). Conclusions More intensive, comprehensive, and longer-term treatment is needed in this high risk population.

Exercise and BMI z-score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta-Analysis of Randomized Trials

AIM

Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents.

METHODS

Randomized exercise intervention trials ≥ 4 weeks were included. Studies were retrieved by searching six electronic databases, cross-referencing and expert review. Dual selection and abstraction occurred. Risk of bias and confidence in cumulative evidence were assessed. Network meta-analysis was performed using multivariate random-effects meta-regression models while surface under the cumulative ranking curves were used to calculate a hierarchy of exercise treatments. The number needed to treat (NNT) and percentile improvement (U₃ ) were also calculated.

RESULTS

Thirty-four studies representing 2,239 participants were included. Median exercise occurred 3 times per week, 50 minutes per session over a 12-week period. Statistically significant reductions in BMI z-score were found for aerobic exercise and combined aerobic and strength exercise, but not strength training alone (M±SD, 95% CI: aerobic, -0.10, -0.15 to -0.05; aerobic and strength, -0.11, -0.19 to -0.03; strength, 0.04, -0.07 to 0.15). Combined aerobic and strength training was ranked best, followed by aerobic exercise and strength training. The NNT was 2 for both aerobic exercise and combined aerobic exercise and strength training. Percentile improvements were 28.8% for aerobic exercise and 31.5% for combined aerobic exercise and strength training. Confidence in effect estimates was ranked as low for aerobic exercise and very low for combined aerobic and strength training as well as strength training.

CONCLUSIONS

Aerobic exercise and combined aerobic exercise and strength training are associated with reductions in BMI z-score.

Treatment of Pediatric Obesity: An Umbrella Systematic Review

OBJECTIVE

Multiple interventions are available to reduce excess body weight in children. We appraised the quality of evidence supporting each intervention and assessed the effectiveness on different obesity-related outcomes.

METHODS

We conducted a systematic search for systematic reviews of randomized controlled trials evaluating pediatric obesity interventions applied for ≥6 months. We assessed the quality of evidence for each intervention using GRADE (Grading of Recommendation, Assessment, Development, and Evaluation) approach.

RESULTS

From 16 systematic reviews, we identified 133 eligible randomized controlled trials. Physical activity interventions reduced systolic blood pressure and fasting glucose (low to moderate quality of evidence). Dietary interventions with low-carbohydrate diets had a similar effect to low-fat diets in terms of body mass index (BMI) reduction (moderate quality of evidence). Educational interventions reduced waist circumference, BMI, and diastolic blood pressure (low quality of evidence). Pharmacological interventions reduced BMI (metformin, sibutramine, orlistat) and waist circumference (sibutramine, orlistat) and increased high-density lipoprotein cholesterol (sibutramine) but also raised systolic and diastolic blood pressure (sibutramine). Surgical interventions (laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass, sleeve gastrectomy) resulted in the largest BMI reduction (moderate quality of evidence). Combined interventions consisting of dietary modification, physical activity, behavioral therapy, and education significantly reduced systolic and diastolic blood pressure, BMI, and triglycerides. Combined parent-child interventions and parent-only interventions had similar effects on BMI (low quality of evidence).

CONCLUSIONS

Several childhood obesity interventions are effective in improving metabolic and anthropometric measures. A comprehensive multicomponent intervention, however, appears to have the best overall outcomes.

Pediatric Obesity-Assessment, Treatment, and Prevention: An Endocrine Society Clinical Practice Guideline

COSPONSORING ASSOCIATIONS

The European Society of Endocrinology and the Pediatric Endocrine Society. This guideline was funded by the Endocrine Society.

OBJECTIVE

To formulate clinical practice guidelines for the assessment, treatment, and prevention of pediatric obesity.

PARTICIPANTS

The participants include an Endocrine Society-appointed Task Force of 6 experts, a methodologist, and a medical writer.

EVIDENCE

This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The Task Force commissioned 2 systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

One group meeting, several conference calls, and e-mail communications enabled consensus. Endocrine Society committees and members and co-sponsoring organizations reviewed and commented on preliminary drafts of this guideline.

CONCLUSION

Pediatric obesity remains an ongoing serious international health concern affecting ∼17% of US children and adolescents, threatening their adult health and longevity. Pediatric obesity has its basis in genetic susceptibilities influenced by a permissive environment starting in utero and extending through childhood and adolescence. Endocrine etiologies for obesity are rare and usually are accompanied by attenuated growth patterns. Pediatric comorbidities are common and long-term health complications often result; screening for comorbidities of obesity should be applied in a hierarchal, logical manner for early identification before more serious complications result. Genetic screening for rare syndromes is indicated only in the presence of specific historical or physical features. The psychological toll of pediatric obesity on the individual and family necessitates screening for mental health issues and counseling as indicated. The prevention of pediatric obesity by promoting healthful diet, activity, and environment should be a primary goal, as achieving effective, long-lasting results with lifestyle modification once obesity occurs is difficult. Although some behavioral and pharmacotherapy studies report modest success, additional research into accessible and effective methods for preventing and treating pediatric obesity is needed. The use of weight loss medications during childhood and adolescence should be restricted to clinical trials. Increasing evidence demonstrates the effectiveness of bariatric surgery in the most seriously affected mature teenagers who have failed lifestyle modification, but the use of surgery requires experienced teams with resources for long-term follow-up. Adolescents undergoing lifestyle therapy, medication regimens, or bariatric surgery for obesity will need cohesive planning to help them effectively transition to adult care, with continued necessary monitoring, support, and intervention. Transition programs for obesity are an uncharted area requiring further research for efficacy. Despite a significant increase in research on pediatric obesity since the initial publication of these guidelines 8 years ago, further study is needed of the genetic and biological factors that increase the risk of weight gain and influence the response to therapeutic interventions. Also needed are more studies to better understand the genetic and biological factors that cause an obese individual to manifest one comorbidity vs another or to be free of comorbidities. Furthermore, continued investigation into the most effective methods of preventing and treating obesity and into methods for changing environmental and economic factors that will lead to worldwide cultural changes in diet and activity should be priorities. Particular attention to determining ways to effect systemic changes in food environments and total daily mobility, as well as methods for sustaining healthy body mass index changes, is of importance.

Accelerometer-determined physical activity and the cardiovascular response to mental stress in children

OBJECTIVES

Cardiovascular reactivity has been associated with future hypertension and cardiovascular mortality. Higher physical activity (PA) has been associated with lower cardiovascular reactivity in adults, but little data is available in children. The purpose of this study was to examine the relationship between PA and cardiovascular reactivity to mental stress in children.

DESIGN

Cross-sectional study.

METHODS

This study sample included children from the Oswego Lead Study (n=79, 46% female, 9-11 years old). Impedance cardiography was performed while children participated in a stress response protocol. Children were also asked to wear Actigraph accelerometers on their wrists for 3 days to measure intensity and duration of PA and sedentary time.

RESULTS

In multivariable models, moderate to vigorous (MV) PA was associated with lower body mass index (BMI) percentile and lower total peripheral resistance (TPR) response to stress (beta=-0.025, p=0.02; beta=-0.009, p=0.05). After additional adjustment for BMI, MVPA was also associated with lower diastolic blood pressure response to stress (beta=-0.01, p=0.03). Total PA and sedentary time were not associated with BMI or cardiovascular responses to stress.

CONCLUSIONS

A modest, inverse relation of PA to vascular reactivity to mental stress was observed in children. These data provide confirmatory evidence that the promotion of PA recommendations for children are important for cardiovascular health.

Protocol for the 'Virtual Traveller' cluster-randomised controlled trial: a behaviour change intervention to increase physical activity in primary-school Maths and English lessons

INTRODUCTION

Physical activity (PA) has been shown to be an important factor for health and educational outcomes in children. However, a large proportion of children's school day is spent in sedentary lesson-time. There is emerging evidence about the effectiveness of physically active lessons: integrating physical movements and educational content in the classroom. 'Virtual Traveller' is a novel 6-week intervention of 10-min sessions performed 3 days per week, using classroom interactive whiteboards to integrate movement into primary-school Maths and English teaching. The primary aim of this project is to evaluate the effect of the Virtual Traveller intervention on children's PA, on-task behaviour and student engagement.

METHODS AND ANALYSIS

This study will be a cluster-randomised controlled trial with a waiting-list control group. Ten year 4 (aged 8-9 years) classes across 10 primary schools will be randomised by class to either the 6-week Virtual Traveller intervention or the waiting-list control group. Data will be collected 5 times: at baseline, at weeks 2 and 4 of the intervention, and 1 week and 3 months postintervention. At baseline, anthropometric measures, 4-day objective PA monitoring (including 2 weekend days; Actigraph accelerometer), PA and on-task behaviour observations and student engagement questionnaires will be performed. All but anthropometric measures will be repeated at all other data collection points. Changes in overall PA levels and levels during different time-periods (eg, lesson-time) will be examined. Changes in on-task behaviour and student engagement between intervention groups will also be examined. Multilevel regression modelling will be used to analyse the data. Process evaluation will be carried out during the intervention period.

ETHICS AND DISSEMINATION

The results of this study will be disseminated through peer-review publications and conference presentations. Ethical approval was obtained through the University College London Research Ethics Committee (reference number: 3500-004).

'FIFA 11 for Health' for Europe. II: effect on health markers and physical fitness in Danish schoolchildren aged 10-12 years

Objectives

To evaluate whether a modified ‘FIFA 11 for Health’ programme for non-communicable diseases had effects on body composition, blood pressure and physical fitness of Danish schoolchildren aged 10–12 years.

Design

A cluster-randomised controlled study with 7 intervention and 2 control schools.

Participants

546 Danish 5th grade municipal schoolchildren allocated to an intervention group (IG; n=402: 11.1±0.4 (±SD) years, 150.1±7.0 cm, 41.3±8.4 kg) and a control group (CG; n=144: 11.0±0.5 years, 151.2±7.8 cm, 41.3±9.0 kg).

Intervention

As part of the physical education (PE) curriculum, IG carried out 2 weekly 45 min ‘FIFA 11 for Health’ sessions focusing on health issues, football skills and 3v3 games. CG continued regular school PE activities. Measurements of body composition, blood pressure at rest, Yo-Yo intermittent recovery level 1 children's test (YYIR1C), balance, jump and sprint performance were performed before and after the 11-week study period.

Results

During the 11-week study period, systolic blood pressure (−3.5 vs 0.9 mm Hg), mean arterial blood pressure (−1.9 vs 0.4 mm Hg), body mass index (−0.02 vs 0.13 kg/m²) and body fat percentage (−0.83% vs −0.04%) decreased more (p<0.05) in IG than in CG. Within-group improvements (p<0.05) were observed in IG for 20 m sprint (4.09±0.29 to 4.06±0.28 s) and YYIR1C performance (852±464 to 896±517 m), but these changes were not significantly different from CG, and balance or jump performance remained unchanged in both groups.

Conclusions

The modified ‘FIFA 11 for Health’ programme has beneficial effects on body composition and blood pressure for Danish schoolchildren aged 10–12 years, thereby providing evidence that this football-based health education programme can directly impact participants' cardiovascular health profile.

Exercise and BMI z-score in overweight and obese children and adolescents: protocol for a systematic review and network meta-analysis of randomised trials

INTRODUCTION

While overweight and obesity in children and adolescents is a major global health problem, the effects of exercise on overweight and obesity in children and adolescents are not well established despite numerous studies on this topic. The purpose of this study is to use the network meta-analytic approach to determine the effects of exercise (aerobic, strength training or both) on body mass index (BMI) z-score in overweight and obese children and adolescents.

METHODS AND ANALYSIS

Randomised exercise intervention trials >4 weeks, published in any language between 1 January 1990 and 31 September 2015, and which include direct and/or indirect evidence, will be included. Studies will be retrieved by searching 6 electronic databases, cross-referencing and expert review. Dual abstraction of data will occur. The primary outcome will be changes in BMI z-score while the secondary outcome will be changes in body weight in kilograms (kg). Risk of bias will be assessed using the Cochrane risk of bias assessment instrument while confidence in the cumulative evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) instrument for network meta-analysis. Network meta-analysis will be performed using multivariate random-effects meta-regression models. The surface under the cumulative ranking curve will be used to provide a hierarchy of exercise treatments (aerobic, strength training or both).

DISSEMINATION

The results of this study will be presented at a professional conference and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

CRD42015026377.

Elevated Urinary T Helper 1 Chemokine Levels in Newly Diagnosed Hypertensive Obese Children

OBJECTIVE

Increasing evidence suggests that T helper (Th) cells play a significant role in the pathogenesis of hypertension. The aim of this study was to evaluate the effect of obesity and anti-hypertensive treatment on urinary Th1 chemokines.

METHODS

The study groups consisted of three types of patients: hypertensive obese, healthy, and non-hypertensive obese. Pre-treatment and post-treatment samples of the hypertensive obese group and one sample from the other two groups were evaluated for urinary chemokine: regulated on activation, normal T cell expressed and secreted (RANTES), interferon-gamma-inducible protein 10 (IP10), and monokine induced by interferon-gamma (MIG). In the hypertensive obese group, urine microalbumin: creatinine ratio was examined before and after treatment. We recommended lifestyle changes to all patients. Captopril was started in those who could not be controlled with lifestyle changes and those who had stage 2 hypertension.

RESULTS

Twenty-four hypertensive obese (mean age 13.1), 27 healthy (mean age 11.2) and 22 non-hypertensive obese (mean age 11.5) children were investigated. The pre-treatment urine albumin: creatinine ratio was positively correlated with pre-treatment MIG levels (r=0.41, p<0.05). RANTES was significantly higher in the pre-treatment hypertensive and non-hypertensive obese group than in the controls. The urinary IP10 and MIG levels were higher in the pre-treatment hypertensive obese group than in the non-hypertensive obese. Comparison of the pre- and post-treatment values indicated significant decreases in RANTES, IP10, and MIG levels in the hypertensive obese group (p<0.05).

CONCLUSION

Th1 cells could be activated in obese hypertensive children before the onset of clinical indicators of target organ damage. Urinary RANTES seemed to be affected by both hypertension and obesity, and urinary IP10 and MIG seemed to be affected predominantly by hypertension.

Exercise intervention and cardiovascular risk factors in obese children. Comparison between obese youngsters taking part in a physical activity school-based programme with and without individualised diet counselling: the ACORDA project

AIM

To determine the effects of a school-based exercise intervention programme on cardiovascular risk factors, including body fat (BF), metabolic profile and physical activity (PA) in children with and without individualised dietary counselling approach (IDC and WIDC).

SUBJECTS AND METHODS

Forty-six overweight children from 6-16 years old (25 girls, 54.3%; age = 10.3 ± 2.8) of six schools took part in an 8-month interdisciplinary, school-based intervention programme. All children were engaged in PA classes, but only one group was exposed to individualised counselling. Blood pressure (BP), lipids and lipoproteins, accelerometer-based PA, percentage of body fat (%BF) and trunk fat (%TF) measures were taken before and after intervention. General Linear Model (Repeated Measures ANOVA) adjusted for age, maturation and height change was used to analyse the longitudinal effect of individualised counselling between two evaluations in each group.

RESULTS

Favourable changes were observed for %BF, %TF, systolic BP and total cholesterol in the IDC group. Subjects WIDC only increased light and moderate-vigorous PA. In IDC, significant effects for time * group interactions were found for systolic BP, total cholesterol and LDL-cholesterol, indicating that counselling might add favourable changes in these markers, beyond those explained by PA and growth.

CONCLUSION

School-based interventions can contribute to counteracting obesity in youth, particularly when individualised dietary counselling is provided. Therefore, the link between schools and professional counselling should be strengthened to ensure consolidated changes towards healthy behaviours.

"Couch-potatoeism" and childhood obesity: The inverse causality hypothesis

The bulk of cross-sectional studies suggests that lower levels of physical activity are associated with childhood obesity. Although this has led to the general understanding that "couch-potatoes" are fat on account of their inactive lifestyles, cross-sectional studies do not imply causality. On the contrary, the contribution of physical activity to obesity during childhood is currently unclear, and lately, studies have suggested that "couch-potatoeism" could be the result of obesity rather than its cause. Coupled with evidence suggesting that interventions have had little effect on children's physical activity levels as well as on obesity, this inverse causality challenges the role of physical activity in childhood obesity prevention strategies.

Physically active lessons as physical activity and educational interventions: a systematic review of methods and results

OBJECTIVE

Physically active lessons aim to increase children's physical activity whilst maintaining academic time. This systematic review aimed to investigate the methods used in such interventions and their effects on physical activity and educational outcomes.

METHODS

In March 2014; PubMed, Web of Science, PsycINFO and ERIC electronic databases were searched. Inclusion criteria were: 1. Classroom lessons containing both PA and educational elements; 2. intervention studies featuring a control group or within-subjects baseline measurement period; 3. any age-group; and 4. English language. Studies assessing physically active lessons within complex interventions were excluded. Data were extracted onto a standardised form. Risk of bias was assessed using the Effective Public Health Practice Project (EPHPP) tool.

RESULTS

Eleven studies were identified: five examined physical activity outcomes only, three examined educational outcomes only and three examined both physical activity and educational outcomes. All studies found improved physical activity following physically active lessons: either in the whole intervention group or in specific demographics. Educational outcomes either significantly improved or were no different compared to inactive teaching. Studies ranged from low to high risk of bias.

CONCLUSIONS

Encouraging evidence of improved physical activity and educational outcomes following physically active lessons is provided. However, too few studies exist to draw firm conclusions. Future high-quality studies with longer intervention periods are warranted.