Repositioning of the global epicentre of non-optimal cholesterol

High blood cholesterol is typically considered a feature of wealthy western countries1,2. However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world3 and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health4,5. However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular risk-changed from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.

National trends in total cholesterol obscure heterogeneous changes in HDL and non-HDL cholesterol and total-to-HDL cholesterol ratio: a pooled analysis of 458 population-based studies in Asian and Western countries

BACKGROUND

Although high-density lipoprotein (HDL) and non-HDL cholesterol have opposite associations with coronary heart disease, multi-country reports of lipid trends only use total cholesterol (TC). Our aim was to compare trends in total, HDL and non-HDL cholesterol and the total-to-HDL cholesterol ratio in Asian and Western countries.

METHODS

We pooled 458 population-based studies with 82.1 million participants in 23 Asian and Western countries. We estimated changes in mean total, HDL and non-HDL cholesterol and mean total-to-HDL cholesterol ratio by country, sex and age group.

RESULTS

Since ∼1980, mean TC increased in Asian countries. In Japan and South Korea, the TC rise was due to rising HDL cholesterol, which increased by up to 0.17 mmol/L per decade in Japanese women; in China, it was due to rising non-HDL cholesterol. TC declined in Western countries, except in Polish men. The decline was largest in Finland and Norway, at ∼0.4 mmol/L per decade. The decline in TC in most Western countries was the net effect of an increase in HDL cholesterol and a decline in non-HDL cholesterol, with the HDL cholesterol increase largest in New Zealand and Switzerland. Mean total-to-HDL cholesterol ratio declined in Japan, South Korea and most Western countries, by as much as ∼0.7 per decade in Swiss men (equivalent to ∼26% decline in coronary heart disease risk per decade). The ratio increased in China.

CONCLUSIONS

HDL cholesterol has risen and the total-to-HDL cholesterol ratio has declined in many Western countries, Japan and South Korea, with only a weak correlation with changes in TC or non-HDL cholesterol.

Effects of the Active Smarter Kids (ASK) physical activity intervention on cardiometabolic risk factors in children: A cluster-randomized controlled trial

The onset of cardiometabolic diseases are recognized to occur in childhood. We aimed to investigate the effect of a school-based cluster-randomized controlled trial of physical activity (PA) on single and clustered cardiometabolic risk factors. We included 1129 fifth-grade children from 57 schools (≥seven children in each class) in Sogn and Fjordane County, Norway, randomized to 28 intervention schools and 29 control schools. The PA intervention was conducted between November 2014 and June 2015. Cardiometabolic risk factors were waist circumference (WC), systolic blood pressure (SBP), total cholesterol (TC):high-density lipoprotein (HDL)-ratio, triglycerides (TG), homeostatic model assessment (HOMA)-score, and cardiorespiratory fitness (CRF). PA was measured by accelerometry. No significant intervention effects were found for single or clustered cardiometabolic risk factors. However, in children with the less favorable baseline values, beneficial effects were found for SBP (p = 0.07 for group ∗ tertile interaction), TC:HDL ratio (p = 0.03 for group ∗ tertile interaction) and the clustered cardiometabolic risk score (p = 0.01 for group ∗ tertile interaction). Compared to boys, girls had a greater effect of the intervention on WC (p = 0.03 for group ∗ sex interaction) and CRF (p < 0.001 for group ∗ sex interaction). The majority of the children had high PA levels, thus limited potential for change, and we found no effects of the PA intervention on cardiometabolic risk in the total sample. However, the intervention had a significantly enhanced effect on fatness and fitness of girls compared to boys. Furthermore, the data suggest that children with the least favorable cardiometabolic risk profile and therefore most in need of change can benefit from school-based PA interventions. Trial registration number: Clinicaltrials.gov ID no.: NCT02132494.

Associations between accelerometry measured physical activity and sedentary time and the metabolic syndrome: A meta-analysis of more than 6000 children and adolescents

BACKGROUND

Metabolic syndrome is increasingly prevalent in the pediatric population. To prevent an early onset, knowledge about its association with modifiable lifestyle factors is needed.

OBJECTIVES

To estimate the prevalence of the metabolic syndrome and examine its cross-sectional associations with physical activity and sedentary time.

METHODS

Participants were 6009 children and adolescents from 8 studies of the International Children's Accelerometry Database. Physical activity and sedentary time were measured by accelerometer. Metabolic syndrome was defined based on International Diabetes Federation criteria. Logistic regression models adjusted for sex, age and monitor wear time were used to examine the associations between physical activity, sedentary time and the metabolic syndrome in each study and effect estimates were combined using random-effects meta-analysis.

RESULTS

The overall prevalence of the metabolic syndrome was 2.9%. In crude models, a 10 min increase in moderate-to-vigorous intensity physical activity and vigorous-intensity physical activity were inversely associated with the metabolic syndrome [OR 0.88, 95% CI 0.82-0.94, OR 0.80, 95% CI 0.70-0.92]. One hour increase in sedentary time was positively associated with the metabolic syndrome [OR 1.28, 95% CI 1.13-1.45]. After adjustment for sedentary time, the association between moderate-to-vigorous-intensity physical activity and the metabolic syndrome remained significant [OR 0.91, 95% CI 0.84-0.99]. Sedentary time was not associated with the metabolic syndrome after adjustment for moderate-to-vigorous intensity physical activity [OR 1.14 95% CI 0.96-1.36].

CONCLUSIONS

Physical activity of at least moderate intensity but not sedentary time is independently associated with the metabolic syndrome.

Dose-response associations between accelerometry measured physical activity and sedentary time and all cause mortality: systematic review and harmonised meta-analysis

OBJECTIVE

To examine the dose-response associations between accelerometer assessed total physical activity, different intensities of physical activity, and sedentary time and all cause mortality.

DESIGN

Systematic review and harmonised meta-analysis.

DATA SOURCES

PubMed, PsycINFO, Embase, Web of Science, Sport Discus from inception to 31 July 2018.

ELIGIBILITY CRITERIA

Prospective cohort studies assessing physical activity and sedentary time by accelerometry and associations with all cause mortality and reported effect estimates as hazard ratios, odds ratios, or relative risks with 95% confidence intervals.

DATA EXTRACTION AND ANALYSIS

Guidelines for meta-analyses and systematic reviews for observational studies and PRISMA guidelines were followed. Two authors independently screened the titles and abstracts. One author performed a full text review and another extracted the data. Two authors independently assessed the risk of bias. Individual level participant data were harmonised and analysed at study level. Data on physical activity were categorised by quarters at study level, and study specific associations with all cause mortality were analysed using Cox proportional hazards regression analyses. Study specific results were summarised using random effects meta-analysis.

MAIN OUTCOME MEASURE

All cause mortality.

RESULTS

39 studies were retrieved for full text review; 10 were eligible for inclusion, three were excluded owing to harmonisation challenges (eg, wrist placement of the accelerometer), and one study did not participate. Two additional studies with unpublished mortality data were also included. Thus, individual level data from eight studies (n=36 383; mean age 62.6 years; 72.8% women), with median follow-up of 5.8 years (range 3.0-14.5 years) and 2149 (5.9%) deaths were analysed. Any physical activity, regardless of intensity, was associated with lower risk of mortality, with a non-linear dose-response. Hazards ratios for mortality were 1.00 (referent) in the first quarter (least active), 0.48 (95% confidence interval 0.43 to 0.54) in the second quarter, 0.34 (0.26 to 0.45) in the third quarter, and 0.27 (0.23 to 0.32) in the fourth quarter (most active). Corresponding hazards ratios for light physical activity were 1.00, 0.60 (0.54 to 0.68), 0.44 (0.38 to 0.51), and 0.38 (0.28 to 0.51), and for moderate-to-vigorous physical activity were 1.00, 0.64 (0.55 to 0.74), 0.55 (0.40 to 0.74), and 0.52 (0.43 to 0.61). For sedentary time, hazards ratios were 1.00 (referent; least sedentary), 1.28 (1.09 to 1.51), 1.71 (1.36 to 2.15), and 2.63 (1.94 to 3.56).

CONCLUSION

Higher levels of total physical activity, at any intensity, and less time spent sedentary, are associated with substantially reduced risk for premature mortality, with evidence of a non-linear dose-response pattern in middle aged and older adults.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018091808.

Cardiometabolic risk factor levels in Norwegian children compared to international reference values: The ASK study

OBJECTIVE

To investigate cardiometabolic risk factor levels in a group of Norwegian 10-year-old children compared to international values and examine the association between cardiorespiratory fitness (CRF) and the reference-standardized clustered risk score.

METHODS

913 children (49% girls) were included from the Active Smarter Kids (ASK) study. Body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC) to HDL-C ratio, triglyceride (TG), glucose, insulin, homeostatic model assessment (HOMA) score and CRF, were standardized according to international age-and sex-specific reference values.

RESULTS

The Norwegian children had significantly more favorable WC, DBP, glucose, HDL-C and CRF levels compared to the international reference values, but similar or less favorable levels of other cardiometabolic risk factors. CRF was the variable that differed the most from the international values (mean (95% CI) 1.20 (1.16 to 1.24) SD). The clustered risk score (excluding CRF) was higher in the Norwegian children, but decreased to below international levels when including CRF (mean (95% CI) - 0.08 (- 0.12 to -0.05) SD). CRF had a significant inverse association with the clustered risk score (excluding CRF) (β - 0.37 SD, 95% CI -0.43 to -0.31).

CONCLUSIONS

Norwegian children have substantially higher CRF levels than international standards, and including CRF in clustered risk scores reduces overall risk in Norwegian children below that of international levels. CRF is associated with improved cardiometabolic health in children.

Physical activity preferences of 10-year-old children and identified activities with positive and negative associations to cardiorespiratory fitness

AIM

This study investigated children's physical activity (PA) preferences, as these can aid the design of school-based interventions.

METHODS

Data were collected in 2014 as a part of the Active Smarter Kids study and 1026 students (52% boys) from 57 Norwegian primary schools completed a questionnaire about their favourite physical activities at a mean age of 10.2 ± 0.3 years. We identified five patterns of PA and studied whether gender, cardiorespiratory fitness and abdominal adiposity were associated with these patterns.

RESULTS

Soccer and slalom skiing were the favourite activities, and the most pronounced gender differences were for activities favoured by girls, which included dancing, gymnastics, exercising to music and jumping rope (p < 0.001). When the five component patterns were analysed using linear mixed-effect models, this showed a strong female preference for dancing, gymnastics, exercising to music and climbing. Cardiovascular fitness was negatively associated with frisbee, dodgeball, baseball and floorball, and positively associated with team handball, volleyball and basketball and with slalom skiing and cross-country skiing. It was interesting that the children's preferences were not related to their abdominal adiposity.

CONCLUSION

The results showed different gender-based PA preferences and positive and negative associations with cardiovascular fitness, but no relationship with abdominal adiposity.

Do Obese Children Achieve Maximal Heart Rate during Treadmill Running?

Objective: Maximal heart rate (HR) is commonly defined as the highest HR obtained during a progressive exercise test to exhaustion. Maximal HR is considered one of the criteria to assess maximum exertion in exercise tests, and is broadly used when prescribing exercise intensity. The aim of the present study was to compare peak HR measurements during maximal treadmill running and active play in obese children and adolescents. Design: Comparison of peak heart rate during active play vs. maximal treadmill running in 39 (7–17 years old, 18 males) obese children and adolescents. Methods: Heart rate was recorded during intensive active play sessions, as well as during a progressive running test on a treadmill until exhaustion. HR, respiratory exchange ratio (RER), and oxygen uptake were continuously measured during the test. The criteria for having reached maximal effort was a subjective assessment by the technician that the participants had reached his or her maximal effort, and a RER above 1.00 or reporting perceived exertion (RPE) above 17 using the Borg-RPE_6–20-Scale. Results: Thirty-four children had a RER ≥1.00, and 37 reported a RPE ≥ 17. Thirty-two children fulfilled both criteria. During active play, peak HR was significantly (p < 0.0001) increased (4%) (mean and 95% confidence intervals; 204 (201, 207) beats/min), compared to during maximal treadmill running (196 (194, 199) beats/min), respectively. Conclusion: The results of the present study indicate that peak heart rate measurements during progressive running to exhaustion in obese children and adolescents cannot necessarily be determined as maximal heart rate.

Waist circumference thresholds and cardiorespiratory fitness

PURPOSE

This study's purpose was to examine whether established risk categories of waist circumference (WC)-normal, high risk, and very high health risk-reflected significant differences in cardiorespiratory fitness (CRF) and physical activity (PA) level.

METHODS

CRF was directly measured as maximal oxygen uptake during a progressive graded treadmill test to exhaustion in 722 individuals (349 women) aged 20-85 years. WC was measured between the lower rib and the iliac crest. Objectively measured PA was assessed using an accelerometer.

RESULTS

Men in the normal risk group (WC < 94 cm) had a 31% higher CRF and 43% higher level of moderate-to-vigorous PA than men in the very high risk group (with a WC > 102 cm). Corresponding numbers for women within normal (WC < 80 cm) and very high risk group (WC > 88 cm) were 25% and 18% (p < 0.05). There was a high negative correlation between CRF and WC in men (r = -0.68), and a moderate correlation for women (r = -0.49; p < 0.001). For each cm increase in WC, CRF was reduced by 0.48 and 0.27 mL/kg/min in men and women, respectively (p < 0.001).

CONCLUSION

The recommended WC thresholds for abdominal obesity reflected significant differences in CRF for both men and women, and could serve as a useful instrument for estimating health-related differences in CRF.

The prospective association between objectively measured sedentary time, moderate-to-vigorous physical activity and cardiometabolic risk factors in youth: a systematic review and meta-analysis

Sedentary time and moderate-to-vigorous physical activity (MVPA) may be uniquely related to cardiometabolic health. Excessive sedentary time is suggested as an independent cardiometabolic risk factor, while MVPA is favourably associated with cardiometabolic health. This systematic review and meta-analysis summarizes the evidence on a prospective relationship between objectively measured sedentary time, MVPA and cardiometabolic health indicators in youth. PubMed, Embase, CINAHL, PhyscINFO and SPORTDiscus were systematically searched from January 2000 until April 2018. Studies were included if sedentary time and physical activity were measured objectively and examined associations with body mass index, waist circumference, triglycerides, high-density lipoprotein, insulin, blood pressure or the clustering of these cardiometabolic risk factors. We identified 30 studies, of which 21 were of high quality. No evidence was found for an association between sedentary time and cardiometabolic outcomes. The association between MVPA and individual cardiometabolic risk factors was inconsistent. The meta-analysis for prospective studies found a small but significant effect size between MVPA at baseline and clustered cardiometabolic risk at follow-up (ES -0.014 [95% CI, -0.024 to -0.004]). We conclude that there is no prospective association between sedentary time and cardiometabolic health, while MVPA is beneficially associated with cardiometabolic health in youth.

Effects of a physical activity intervention on schoolchildren's health-related quality of life: The active smarter kids (ASK) cluster-randomized controlled trial

We investigated whether a seven-month (November 2014 to June 2015), school-based cluster-randomized controlled physical activity intervention improved health-related quality of life (HRQoL) in 10-year old children. The participants (N = 1229) from 57 elementary schools in Sogn og Fjordane County, Norway, were cluster-randomized by school either to the intervention (I) or control (C) group. The planned intervention in the 28 I-schools was 300 min of physical activity per week, compared to 135 min in the 29C-schools. HRQoL was assessed by self-report, using the Kidscreen-27 questionnaire. Objectively measured physical activity did not differ between the I–schools and C-schools during the intervention. No effect of the intervention was found for HRQoL: Physical well-being (P = 0.789), Psychological well-being (P = 0.682), Autonomy & parents (P = 0.662), Social support & peers (P = 0.828) and School environment (P = 0.074). In conclusion, the ASK school-based physical activity intervention showed no significant effect on HRQoL.

Reference values for cardiometabolic risk scores in children and adolescents: Suggesting a common standard

BACKGROUND AND AIMS

International reference values for cardiometabolic risk variables, to allow for standardization of continuous risk scores in children, are not currently available. The aim of this study was to provide international age- and gender-specific reference values for cardiometabolic risk factors in children and adolescents.

METHODS

Cohorts of children sampled from different parts of Europe (North, South, Mid and Eastern) and from the United States were pooled. In total, 22,479 observations (48.7% European vs. 51.3% American), 11,234 from girls and 11,245 from boys, aged 6-18 years were included in the study. Linear mixed-model regression analysis was used to analyze the associations between age and each cardiometabolic risk factor.

RESULTS

Reference values for 14 of the most commonly used cardiometabolic risk variables in clustered risk scores were calculated and presented by age and gender: systolic blood pressure (SBP), diastolic blood pressure (DBP), waist circumference (WC), body mass index (BMI), sum of 4 skinfolds (sum4skin), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), TC:HDL-C ratio, glucose, insulin, homeostatic model assessment-score (HOMA-score), and cardiorespiratory fitness (CRF).

CONCLUSIONS

This study suggests a common standard to define cardiometabolic risk in children. Adapting this approach makes single risk factors and clustered cardiometabolic disease risk scores comparable to the reference material itself and comparable to cardiometabolic risk values in studies using the same strategy. This unified approach therefore increases the prospect to estimate and compare prevalence and trends of cardiometabolic risk in children when using continuous cardiometabolic risk scores.

Sedentary Time and Physical Activity Surveillance Through Accelerometer Pooling in Four European Countries

Objective

The objective of this study was to pool, harmonise and re-analyse national accelerometer data from adults in four European countries in order to describe population levels of sedentary time and physical inactivity.

Methods

Five cross-sectional studies were included from England, Portugal, Norway and Sweden. ActiGraph accelerometer count data were centrally processed using the same algorithms. Multivariable logistic regression analyses were conducted to study the associations of sedentary time and physical inactivity with sex, age, weight status and educational level, in both the pooled sample and the separate study samples.

Results

Data from 9509 participants were used. On average, participants were sedentary for 530 min/day, and accumulated 36 min/day of moderate to vigorous intensity physical activity. Twenty-three percent accumulated more than 10 h of sedentary time/day, and 72% did not meet the physical activity recommendations. Nine percent of all participants were classified as high sedentary and low active. Participants from Norway showed the highest levels of sedentary time, while participants from England were the least physically active. Age and weight status were positively associated with sedentary time and not meeting the physical activity recommendations. Men and higher-educated people were more likely to be highly sedentary, while women and lower-educated people were more likely to be inactive.

Conclusions

We found high levels of sedentary time and physical inactivity in four European countries. Older people and obese people were most likely to display these behaviours and thus deserve special attention in interventions and policy planning. In order to monitor these behaviours, accelerometer-based cross-European surveillance is recommended.

Electronic supplementary material

The online version of this article (doi:10.1007/s40279-016-0658-y) contains supplementary material, which is available to authorized users.

Cross-sectional and prospective associations between sleep, screen time, active school travel, sports/exercise participation and physical activity in children and adolescents

BACKGROUND

The aim of this study was to investigate how sleep, screen time, active school travel and sport and/or exercise participation associates with moderate-to-vigorous physical activity (MVPA) in nationally representative samples of Norwegian 9- and 15-y-olds, and whether these four behaviors at age nine predict change in MVPA from age nine to 15 years.

METHOD

We pooled cross-sectional accelerometer and questionnaire data from 9- (n = 2366) and 15-y-olds (n = 1554) that participated in the first (2005/06) and second (2011/12) wave of the Physical Activity among Norwegian Children Study to investigate cross-sectional associations. To investigate prospective associations, we used data from a sub-sample that participated in both waves (at age nine and 15 years, n = 517).

RESULTS

Cross-sectional analyses indicated a modest, inverse association between screen time and MVPA among 9- (- 2.2 min/d (95% CI: -3.1, - 1.3)) and 15-y-olds (- 1.7 min/d (95% CI: -2.7, - 0.8)). Compared to their peers with 0-5 min/d of active travel to school, 9- and 15-y-olds with ≥16 min/d accumulated 7.2 (95% CI: 4.0, 10.4) and 9.0 (95% CI: 3.8, 14.1) more min/d of MVPA, respectively. Nine-y-old boys and 15-y-olds reporting ≥8 h/week of sports and/or exercise participation accumulated 14.7 (95% CI: 8.2, 21.3) and 17.9 (95% CI: 14.0, 21.8) more min/d of MVPA, respectively, than those reporting ≤2 h/week. We found no cross-sectional association between sleep duration and MVPA in either age group. None of the four behaviors predicted change in MVPA from age nine to 15 years (p ≥ 0.102).

CONCLUSION

Active travel to school and sport/exercise participation may be important targets for future interventions aimed at increasing MVPA in children and adolescents. However, future studies are needed to determine causality.

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: a pooled analysis of 1018 population-based measurement studies with 88.6 million participants

BACKGROUND

Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure.

METHODS

We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probit-transformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure.

RESULTS

In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the high-income Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association.

CONCLUSIONS

Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups.

Gender-specific effects of physical activity on children's academic performance: The Active Smarter Kids cluster randomized controlled trial

Active learning combines academic content with physical activity (PA) to increase child PA and academic performance, but the impact of active learning is mixed. It may be that this is a moderated relationship in which active learning is beneficial for only some children. This paper examine the impact of baseline academic performance and gender as moderators for the effects of active learning on children's academic performance. In the ASK-study, 1129 fifth-graders from 57 Norwegian elementary schools were randomized by school to intervention or control in a physical activity intervention between November 2014 and June 2015. Academic performance in numeracy, reading, and English was measured and a composite score was calculated. Children were split into low, middle and high academic performing tertiles. 3-way-interactions for group (intervention, control)∗gender (boys, girls)∗academic performance (tertiles) were investigated using mixed model regression. There was a significant, 3-way-interaction (p=0.044). Both boys (ES=0.11) and girls (ES=0.18) in the low performing tertile had a similar beneficial trend. In contrast, middle (ES=0.03) and high performing boys (ES=0.09) responded with small beneficial trends, while middle (ES=-0.11) and high performing girls (ES=-0.06) responded with negative trends. ASK was associated with a significant increase in academic performance for low performing children. It is likely that active learning benefited children most in need of adapted education but it may have a null or negative effect for those girls who are already performing well in the sedentary classroom. Differences in gendered responses are discussed as a possible explanation for these results.

TRIAL REGISTRATION

Clinicaltrials.gov registry, trial registration number: NCT02132494.

The effect of a two-year school-based daily physical activity intervention on a clustered CVD risk factor score-The Sogndal school-intervention study

To evaluate changes in clustered cardiovascular disease (CVD) risk factors in 9-year-old children following a 2-year school-based physical activity intervention. In total, 259 children (age 9.3 ± 0.3 years) were invited, of whom 256 participated. The intervention group (63 boys, 62 girls) carried out 60-minute teacher-controlled daily physical activity over two school years. The control group (62 boys, 69 girls) had the curriculum-defined amount of physical education (45 minutes twice each week). Of these, 67% (171 total, 91 intervention) successfully completed both baseline and post-intervention of six CVD risk factors: systolic blood pressure (SBP), triglyceride (TG), total cholesterol-to-high-density lipoprotein cholesterol ratio (TC:HDL ratio), waist circumference (WC), the homeostasis model assessment for insulin resistance (HOMA), and peak oxygen uptake (VO_2peak ). All variables were standardized by sex prior to constructing a cluster score (sum of z scores for all variables). The effect of the intervention on the cluster score was analyzed using linear multiple regression. The cluster score improved after the intervention (ES = .29). Furthermore, the analyses showed significant effects in favor of the intervention group for systolic blood pressure (ES = .35), total cholesterol-to-HDL-c ratio (ES = .23), triglyceride (ES = .40), and VO_2peak (ES = .57). A teacher-led school-based physical activity intervention that is sufficiently long and includes a substantial amount of daily physical activity can beneficially modify children's clustered CVD risk profile.

Associations of Vigorous-Intensity Physical Activity with Biomarkers in Youth

INTRODUCTION

Physical activity (PA) conveys known cardiometabolic benefits to youth, but the contribution of vigorous-intensity PA (VPA) to these benefits is unknown. Therefore, we sought to determine (a) the associations between VPA and cardiometabolic biomarkers independent of moderate-intensity PA (MPA) and time sedentary and (b) the accelerometer cut point that best represents the threshold for health-promoting VPA in youth.

METHODS

Data from the International Children's Accelerometry Database (ICAD) were analyzed in 2015. The relationship between cardiometabolic biomarkers and four categories of VPA estimated via three sets of cut points were examined using isotemporal substitution quantile regression modeling at the 10th, 25th, 50th, 75th, and 90th percentile of the distribution of each biomarker, separately. Age, sex, accelerometer wear time, sedentary time, and MPA were controlled for while allowing substitution for light-intensity PA. Data from 11,588 youth (4-18 yr) from 11 ICAD studies (collected 1998-2009) were analyzed.

RESULTS

Only 32 of 360 significant associations were observed. Significant, negative relationships were observed for VPA with waist circumference and insulin. Replacing light-intensity PA with VPA (corresponding to at the 25th to 90th percentiles of VPA) was associated with 0.67 (-1.33 to -0.01; P = 0.048) to 7.30 cm (-11.01 to -3.58; P < 0.001) lower waist circumference using Evenson and ICAD cut points (i.e., higher counts per minute). VPA levels were associated with 12.60 (-21.28 to -3.92; P = 0.004) to 27.03 pmol·L (-45.03 to -9.03; P = 0.003) lower insulin levels at the 75th to 90th percentiles using Evenson and ICAD cut points when substituted for light PA.

CONCLUSIONS

Substituting light PA with VPA was inversely associated with waist circumference and insulin. However, VPA was inconsistently related to the remaining biomarkers after controlling for time sedentary and MPA.

Moderate-to-vigorous physical activity, but not sedentary time, predicts changes in cardiometabolic risk factors in 10-y-old children: the Active Smarter Kids Study

Background: Cross-sectional data have suggested an inverse relation between physical activity and cardiometabolic risk factors that is independent of sedentary time. However, little is known about which subcomponent of physical activity may predict cardiometabolic risk factors in youths.Objective: We examined the independent prospective associations between objectively measured sedentary time and subcomponents of physical activity with individual and clustered cardiometabolic risk factors in healthy children aged 10 y.Design: We included 700 children (49.1% males; 50.9% females) in which sedentary time and physical activity were measured with the use of accelerometry. Systolic blood pressure, waist circumference (WC), and fasting blood sample (total cholesterol, high-density lipoprotein cholesterol, triglycerides, glucose, fasting insulin) were measured with the use of standard clinical methods and analyzed individually and as a clustered cardiometabolic risk score standardized by age and sex (z score). Exposure and outcome variables were measured at baseline and at follow-up 7 mo later.Results: Sedentary time was not associated with any of the individual cardiometabolic risk factors or clustered cardiometabolic risk in prospective analyses. Moderate physical activity at baseline predicted lower concentrations of triglycerides (P = 0.021) and homeostatic model assessment for insulin resistance (P = 0.027) at follow-up independent of sex, socioeconomic status, Tanner stage, monitor wear time, or WC. Moderate-to-vigorous physical activity (P = 0.043) and vigorous physical activity (P = 0.028) predicted clustered cardiometabolic risk at follow-up, but these associations were attenuated after adjusting for WC.Conclusions: Physical activity, but not sedentary time, is prospectively associated with cardiometabolic risk in healthy children. Public health strategies aimed at improving children's cardiometabolic profile should strive for increasing physical activity of at least moderate intensity rather than reducing sedentary time. This trial was registered at clinicaltrials.gov as NCT02132494.