Children's moderate-to-vigorous physical activity on weekdays versus weekend days: a multi-country analysis.

PURPOSE: The Structured Days Hypothesis (SDH) posits that children's behaviors associated with obesity - such as physical activity - are more favorable on days that contain more 'structure' (i.e., a pre-planned, segmented, and adult-supervised environment) such as school weekdays, compared to days with less structure, such as weekend days. The purpose of this study was to compare children's moderate-to-vigorous physical activity (MVPA) levels on weekdays versus weekend days using a large, multi-country, accelerometer-measured physical activity dataset. METHODS: Data were received from the International Children's Accelerometer Database (ICAD) July 2019. The ICAD inclusion criteria for a valid day of wear, only non-intervention data (e.g., baseline intervention data), children with at least 1 weekday and 1 weekend day, and ICAD studies with data collected exclusively during school months, were included for analyses. Mixed effects models accounting for the nested nature of the data (i.e., days within children) assessed MVPA minutes per day (min/day MVPA) differences between weekdays and weekend days by region/country, adjusted for age, sex, and total wear time. Separate meta-analytical models explored differences by age and country/region for sex and child weight-status. RESULTS/FINDINGS: Valid data from 15 studies representing 5794 children (61% female, 10.7 ± 2.1 yrs., 24% with overweight/obesity) and 35,263 days of valid accelerometer data from 5 distinct countries/regions were used. Boys and girls accumulated 12.6 min/day (95% CI: 9.0, 16.2) and 9.4 min/day (95% CI: 7.2, 11.6) more MVPA on weekdays versus weekend days, respectively. Children from mainland Europe had the largest differences (17.1 min/day more MVPA on weekdays versus weekend days, 95% CI: 15.3, 19.0) compared to the other countries/regions. Children who were classified as overweight/obese or normal weight/underweight accumulated 9.5 min/day (95% CI: 6.9, 12.2) and 10.9 min/day (95% CI: 8.3, 13.5) of additional MVPA on weekdays versus weekend days, respectively. CONCLUSIONS: Children from multiple countries/regions accumulated significantly more MVPA on weekdays versus weekend days during school months. This finding aligns with the SDH and warrants future intervention studies to prioritize less-structured days, such as weekend days, and to consider providing opportunities for all children to access additional opportunities to be active.

Exploring the importance of diversified physical activities in early childhood for later motor competence and physical activity level: a seven-year longitudinal study.

BACKGROUND: Research indicates that childhood motor competence (MC) can predict physical activity (PA) levels later in life and it has been argued that frequently engaging in a wide diversity of physical activities will eventually improve children's MC. However, no longitudinal or experimental studies have confirmed this theoretical rationale. The aims of this study are to explore the longitudinal associations between diversified physical activities at age six and later MC and PA (time spent in moderate-to-vigorous PA) (age nine and 13). Furthermore, we explore to what extent the longitudinal association between diversified physical activity and PA is mediated by MC. METHODS: Longitudinal data from the Copenhagen School Intervention Study were used for this analysis, where 704 participated (69% response rate). Diversified physical activity (self-reported), MC (The Körperkoordinationstest für Kinder battery of postural stability and locomotor skills) and PA (accelerometer) were assessed in the children at age six, age nine and age 13. A total of 654 participated in at least two of the measures and, therefore, were included in the analysis. Two structural equation models were constructed, with diversified physical activity at age six and MC and PA at age nine as predictors of PA and MC at age 13. RESULTS: The data from both models demonstrated good model fit. Diversified physical activity at 6 years of age was significantly associated with physical activity and MC at age 13, when adjusting for sex, age, intervention, weight, height, and previous levels of PA and MC. Diversified physical activity at age six was also positively associated with PA and MC at age nine, which were, in turn, positively related to PA at age 13 but to a lesser degree than diversified PA at age six. The association between diversified physical activity at age six and PA at age 13 was not mediated by MC at age nine. CONCLUSIONS: The results of this study indicate that diversified physical activity at age six is important for the development of MC and PA in adolescence. Increasing the diversity of children's daily physical activities, not only the amount and intensity, seems important for future PA behavior and thereby health promotion in a life course perspective.

Metabolic risk associated with liver enzymes, uric acid, and hemoglobin in adolescents.

BACKGROUND: The associations of renal, hepatic, and hematologic markers with metabolic risk (MR) have already been shown in adolescents. However, it is still controversial which marker best predicts metabolic changes in youth. The aim of this study was to verify the association of MR with alanine aminotransferase (ALT), aspartate aminotransferase (AST), uric acid, and hemoglobin (Hb) in adolescents. METHODS: We evaluated 1713 Brazilian adolescents aged 10 to 17 years. MR was calculated using a continuous metabolic risk score, including the sum of Z-scores of waist circumference, systolic blood pressure, fasting glucose, high-density lipoproteins, triglycerides, and cardiorespiratory fitness. Cutoff points were set for MR prediction for five metabolic components (ALT, AST, AST/ALT ratio, uric acid, and Hb). RESULTS: MR was strongly associated with increased uric acid (odds ratio [OR]: 2.50; 95% confidence interval [CI]: 1.74-3.59), ALT (OR: 2.64; 95% CI: 1.63-4.27), and AST levels (OR: 2.53; 95% CI: 1.24-5.18). Uric acid was shown to be the best predictor for MR (sensitivity: 55.79%; specificity: 61.35%; area under the curve: 0.616). CONCLUSION: Elevated hepatic, renal, and hematological markers were associated with MR in adolescents, especially ALT, AST, and uric acid levels. IMPACT: Elevated hepatic, renal, and hematological markers were associated with metabolic risk in adolescents, especially ALT, AST, and uric acid levels. It is still controversial which marker best predicts metabolic changes in adolescents. In addition, association of Hb with metabolic risk is under-studied in this population. It is important to further investigate the relationship between elevated Hb and hepatic markers, since there are key aspects not addressed yet. Our results highlight the importance of creating public health policies aimed to child and adolescent population, to prevention of metabolic disorders from an early age.

Tracking of total sedentary time and sedentary patterns in youth: a pooled analysis using the International Children's Accelerometry Database (ICAD).

BACKGROUND: To gain more understanding of the potential health effects of sedentary time, knowledge is required about the accumulation and longitudinal development of young people's sedentary time. This study examined tracking of young peoples' total and prolonged sedentary time as well as their day-to-day variation using the International Children's Accelerometry Database. METHODS: Longitudinal accelerometer data of 5991 children (aged 4-17y) was used from eight studies in five countries. Children were included if they provided valid (≥8 h/day) accelerometer data on ≥4 days, including ≥1 weekend day, at both baseline and follow-up (average follow-up: 2.7y; range 0.7-8.2). Tracking of total and prolonged (i.e. ≥10-min bouts) sedentary time was examined using multilevel modelling to adjust for clustering of observations, with baseline levels of sedentary time as predictor and follow-up levels as outcome. Standardized regression coefficients were interpreted as tracking coefficients (low: < 0.3; moderate: 0.3-0.6; high: > 0.6). RESULTS: Average total sedentary time at study level ranged from 246 to 387 min/day at baseline and increased annually by 21.4 min/day (95% confidence interval [19.6-23.0]) on average. This increase consisted almost entirely of prolonged sedentary time (20.9 min/day [19.2-22.7]). Total (standardized regression coefficient (B) = 0.48 [0.45-0.50]) and prolonged sedentary time (B = 0.43 [0.41-0.45]) tracked moderately. Tracking of day-to-day variation in total (B = 0.04 [0.02-0.07]) and prolonged (B = 0.07 [0.04-0.09]) sedentary time was low. CONCLUSION: Young people with high levels of sedentary time are likely to remain among the people with highest sedentary time as they grow older. Day-to-day variation in total and prolonged sedentary time, however, was rather variable over time.

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.

Exposure to perfluoroalkylated substances (PFAS) in relation to fitness, physical activity, and adipokine levels in childhood: The european youth heart study.

BACKGROUND: perfluoroalkylated substances (PFAS) are highly persistent chemicals that are able to alter the human metabolism - potentially via disruption of cell signaling pathways mediated by adipokines. Both adiponectin and leptin are influenced by and exert influence on energy storage and energy expenditure, wherefore associations between PFAS and adipokines may be mediated by fitness and fat mass. OBJECTIVES: the aim of this cross-sectional study was to investigate the association between childhood exposure to PFAS and adipokines (adiponectin and leptin), while considering associations between PFAS and children's level of fitness, physical activity and fat mass to elucidate potential mediation by fitness, physical activity and fat mass. METHODS: 9-year old children from Danish public schools were recruited in the European Youth Heart Study in 1997. For this study only children with valid measures on PFAS (PFOS, PFOA, PFNA, PFDA and PFHxS), adipokines (adiponectin and leptin), fitness, fat mass and co-variates (parity and maternal income) were included (N = 242). Multiple linear regression models with and without conditioning and causal mediation analysis were applied. RESULTS: this study found inverse associations between PFOA, PFDA and PFHxS and leptin. PFOA was positively associated with adiponectin, whereas PFHxS was inversely associated with adiponectin in boys. Latter association seemed to be mediated by fat mass. Associations with leptin showed indirect effects of fitness and fat mass but were unable to demonstrate significant mediation. Neither PFOS nor PFNA were associated with the outcome. DISCUSSION: these results may indicate a favorable leptin profile with increasing PFAS, although the results could be driven by residual negative confounding from socio-economic factors and mediation by fitness and fat mass.

Correction to: Physical activity intensity, bout-duration, and cardiometabolic risk markers in children and adolescents.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Effects of physical activity interventions on cognitive and academic performance in children and adolescents: a novel combination of a systematic review and recommendations from an expert panel.

OBJECTIVE: To summarise the current evidence on the effects of physical activity (PA) interventions on cognitive and academic performance in children, and formulate research priorities and recommendations. DESIGN: Systematic review (following PRISMA guidelines) with a methodological quality assessment and an international expert panel. We based the evaluation of the consistency of the scientific evidence on the findings reported in studies rated as of high methodological quality. DATA SOURCES: PubMed, PsycINFO, Cochrane Central, Web of Science, ERIC, and SPORTDiscus. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: PA-intervention studies in children with at least one cognitive or academic performance assessment. RESULTS: Eleven (19%) of 58 included intervention studies received a high-quality rating for methodological quality: four assessed effects of PA interventions on cognitive performance, six assessed effects on academic performance, and one on both. All high-quality studies contrasted the effects of additional/adapted PA activities with regular curriculum activities. For cognitive performance 10 of 21 (48%) constructs analysed showed statistically significant beneficial intervention effects of PA, while for academic performance, 15 of 25 (60%) analyses found a significant beneficial effect of PA. Across all five studies assessing PA effects on mathematics, beneficial effects were reported in six out of seven (86%) outcomes. Experts put forward 46 research questions. The most pressing research priority cluster concerned the causality of the relationship between PA and cognitive/academic performance. The remaining clusters pertained to PA characteristics, moderators and mechanisms governing the 'PA-performance' relationship and miscellaneous topics. CONCLUSION: There is currently inconclusive evidence for the beneficial effects of PA interventions on cognitive and overall academic performance in children. We conclude that there is strong evidence for beneficial effects of PA on maths performance.The expert panel confirmed that more 'high-quality' research is warranted. By prioritising the most important research questions and formulating recommendations we aim to guide researchers in generating high-quality evidence. Our recommendations focus on adequate control groups and sample size, the use of valid and reliable measurement instruments for physical activity and cognitive performance, measurement of compliance and data analysis. PROSPERO REGISTRATION NUMBER: CRD42017082505.

Physical activity intensity, bout-duration, and cardiometabolic risk markers in children and adolescents.

OBJECTIVES: To determine the role of physical activity intensity and bout-duration in modulating associations between physical activity and cardiometabolic risk markers. METHODS: A cross-sectional study using the International Children's Accelerometry Database (ICAD) including 38,306 observations (in 29,734 individuals aged 4-18 years). Accelerometry data was summarized as time accumulated in 16 combinations of intensity thresholds (≥500 to ≥3000 counts/min) and bout-durations (≥1 to ≥10 min). Outcomes were body mass index (BMI, kg/m2), waist circumference, biochemical markers, blood pressure, and a composite score of these metabolic markers. A second composite score excluded the adiposity component. Linear mixed models were applied to elucidate the associations and expressed per 10 min difference in daily activity above the intensity/bout-duration combination. Estimates (and variance) from each of the 16 combinations of intensity and bout-duration examined in the linear mixed models were analyzed in meta-regression to investigate trends in the association. RESULTS: Each 10 min positive difference in physical activity was significantly and inversely associated with the risk factors irrespective of the combination of intensity and bout-duration. In meta-regression, each 1000 counts/min increase in intensity threshold was associated with a -0.027 (95% CI: -0.039 to -0.014) standard deviations lower composite risk score, and a -0.064 (95% CI: -0.09 to -0.038) kg/m2 lower BMI. Conversely, meta-regression suggested bout-duration was not significantly associated with effect-sizes (per 1 min increase in bout-duration: -0.002 (95% CI: -0.005 to 0.0005) standard deviations for the composite risk score, and -0.005 (95% CI: -0.012 to 0.002) kg/m2 for BMI). CONCLUSIONS: Time spent at higher intensity physical activity was the main determinant of variation in cardiometabolic risk factors, not bout-duration. Greater magnitude of associations was consistently observed with higher intensities. These results suggest that, in children and adolescents, physical activity, preferably at higher intensities, of any bout-duration should be promoted.

Testing physical function in children undergoing intense cancer treatment-a RESPECT feasibility study.

BACKGROUND: The physical function of children with cancer is reduced during treatment, which can compromise the quality of life and increase the risk of chronic medical conditions. The study, "REhabilitation, including Social and Physical activity and Education in Children and Teenagers with cancer" (Clinicaltrials.gov: NCT01772862) examines the efficacy of multimodal rehabilitation strategies introduced at cancer diagnosis. This article addresses the feasibility of and obstacles to testing physical function in children with cancer. METHODS: The intervention group comprised 46 males and 29 females aged 6-18 years (mean ± SD: 11.3 ± 3.1 years) diagnosed with cancer from January 2013 to April 2016. Testing at diagnosis and after 3 months included timed-up-and-go, sit-to-stand, flamingo balance, handgrip strength, and the bicycle ergometer cardiopulmonary exercise test (CPET). RESULTS: Of the 75 children, 92% completed a minimum of one test; two children declined testing and four were later included. Completion was low for CPET (38/150, 25%) but was high for handgrip strength (122/150, 81%). Tumor location, treatment-related side effects, and proximity to chemotherapy administration were primary obstacles for testing physical function. Children with extracranial solid tumors and central nervous system tumors completed significantly fewer tests than those with leukemia and lymphoma. Children with leukemia demonstrated reduced lower extremity function, that is, 24% reduction at 3 months testing in timed-up-and-go (P = 0.005) and sit-to-stand (P = 0.002), in contrast with no reductions observed in the other diagnostic groups. CONCLUSION: Children with cancer are generally motivated to participate in physical function tests. Future studies should address diagnosis specific obstacles and design testing modalities that facilitate physical function tests in this target group.

Galectin-3 levels relate in children to total body fat, abdominal fat, body fat distribution, and cardiac size.

Galectin-3 has recently been proposed as a novel biomarker for cardiovascular disease in adults. The purpose of this investigation was to assess relationships between galectin-3 levels and total body fat, abdominal fat, body fat distribution, aerobic fitness, blood pressure, left ventricular mass, left atrial size, and increase in body fat over a 2-year period in a population-based sample of children. Our study included 170 children aged 8-11 years. Total fat mass and abdominal fat were measured by dual-energy x-ray absorptiometry (DXA). Body fat distribution was expressed as abdominal fat/total fat mass. Maximal oxygen uptake was assessed by indirect calorimetry during a maximal exercise test and scaled to body mass. Systolic and diastolic blood pressure and pulse pressure were measured. Left atrial size, left ventricular mass, and relative wall thickness were measured by echocardiography. Frozen serum samples were analyzed for galectin-3 by the Proximity Extension Assay technique. A follow-up DXA scan was performed in 152 children 2 years after the baseline exam. Partial correlations, with adjustment for sex and age, between galectin-3 versus body fat measurements indicated weak to moderate relationships. Moreover, left atrial size, left ventricular mass, and relative wall thickness and pulse pressure were also correlated with galectin-3. Neither systolic blood pressure nor maximal oxygen uptake was correlated with galectin-3. There was also a correlation between galectin-3 and increase in total body fat over 2 years, while no such correlations were found for the other fat measurements. CONCLUSION: More body fat and abdominal fat, more abdominal body fat distribution, more left ventricular mass, and increased left atrial size were all associated with higher levels of galectin-3. Increase in total body fat over 2 years was also associated with higher levels of galectin-3. What is Known: • Galectin-3 has been linked to obesity and been proposed to be a novel biomarker for cardiovascular disease in adults. • Information on this subject in children is very scarce. What is New: • The present study demonstrates a relationship between galectin-3 levels and total body fat, abdominal fat, body fat distribution, cardiac size and geometry, and increase in total body fat over 2 years in young children.

School-based study found that physical activity and aerobic fitness predicted increases in total body fat and abdominal fat at a mean age of 9.8 years.

AIM: We assessed whether baseline measurements of physical activity, aerobic fitness, body fat and abdominal fat were predictors of changes in body fat measurements over a two-year period. METHODS: The study comprised of 204 children aged 9.8 ± 0.6 years with a normal body mass distribution, who recruited from four schools in middle-class areas of Malmö, Sweden, from 2001 to 2004. Peak oxygen uptake and physical activity were measured at baseline. Body fat was measured by dual-energy X-ray absorptiometry at baseline and two years later. RESULTS: Physical activity, aerobic fitness and total body fat or abdominal fat were predictors of change in total body fat or abdominal fat over a period of two years. Changes in the percentage of body fat were not related to any of the baseline measurements. CONCLUSION: Our two-year follow-up of children with a mean age of 9.8 years at baseline showed that physical activity, aerobic fitness and body fat or abdominal fat predicted changes in total body fat or abdominal fat, but not the percentage of body fat.

Effect of Low- Versus High-Intensity Exercise Training on Biomarkers of Inflammation and Endothelial Dysfunction in Adolescents With Obesity: A 6-Month Randomized Exercise Intervention Study.

PURPOSE: To investigate the effects of a low- versus high-intensity aerobic training on biomarkers of inflammation and endothelial dysfunction in adolescents with obesity. METHODS: Sixty-two adolescents with obesity [age = 15 (14) y, body mass index = 34.87 (4.22) kg·m-2] were randomized to receive either a high-intensity training (HIT, n = 31) or a low-intensity training (LIT, n = 31) for 24 weeks. All participants also received nutritional, psychological, and clinical counseling. Leptin, total and subtype leukocyte counts, tumor necrosis factor-alpha, interleukin-6, myeloperoxidase, soluble intercellular adhesion molecule-1, and soluble vascular cell adhesion molecule-1 were obtained at baseline and after 24 weeks. RESULTS: HIT reduced neutrophils [from 4.4 (1.9) to 3.6 (1.3) µL-1 × 103; P = .01] and monocytes [from 7.2 (2.5) to 5.2 (1.8) µL-1 × 102; P < .01], but LIT increased neutrophils [from 4.5 (1.7) to 5.2 (3.3) µL-1 × 103; P = .01]. Although tumor necrosis factor-alpha increased in LIT [from 13.3 (7.5) to 17.7 (10.8) pg·mL-1; P = .01], it decreased in HIT [from 12.4 (7.5) to 11.3 (6.2) pg·mL-1; P = .01]. No changes in leukocyte counts, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and homeostasis assessment model for insulin resistance were observed. CONCLUSIONS: Both HIT and LIT improved the inflammatory profile. The study, however, indicated that the number of biomarkers and the magnitude of changes were higher in the HIT compared with LIT.

Effects of physical activity on schoolchildren's academic performance: The Active Smarter Kids (ASK) cluster-randomized controlled trial.

OBJECTIVE: To investigate the effect of a seven-month, school-based cluster-randomized controlled trial on academic performance in 10-year-old children. METHODS: In total, 1129 fifth-grade children from 57 elementary schools in Sogn og Fjordane County, Norway, were cluster-randomized by school either to the intervention group or to the control group. The children in the 28 intervention schools participated in a physical activity intervention between November 2014 and June 2015 consisting of three components: 1) 90min/week of physically active educational lessons mainly carried out in the school playground; 2) 5min/day of physical activity breaks during classroom lessons; 3) 10min/day physical activity homework. Academic performance in numeracy, reading and English was measured using standardized Norwegian national tests. Physical activity was measured objectively by accelerometry. RESULTS: We found no effect of the intervention on academic performance in primary analyses (standardized difference 0.01-0.06, p>0.358). Subgroup analyses, however, revealed a favorable intervention effect for those who performed the poorest at baseline (lowest tertile) for numeracy (p=0.005 for the subgroup∗group interaction), compared to controls (standardized difference 0.62, 95% CI 0.19-1.07). CONCLUSIONS: This large, rigorously conducted cluster RCT in 10-year-old children supports the notion that there is still inadequate evidence to conclude that increased physical activity in school enhances academic achievement in all children. Still, combining physical activity and learning seems a viable model to stimulate learning in those academically weakest schoolchildren.

Cardiorespiratory fitness cut points to avoid cardiovascular disease risk in children and adolescents; what level of fitness should raise a red flag? A systematic review and meta-analysis.

BACKGROUND: Poor cardiorespiratory fitness is associated with cardiovascular disease risk factors. AIM: To perform a systematic review and meta-analysis of the relationship between poor cardiorespiratory fitness and cardiovascular disease risk in children and adolescents. METHODS: Systematic literature search (1980 to 11 April 2015) for studies that determined a cardiorespiratory fitness cut point that predicted cardiovascular disease risk in children and adolescents. RESULTS: We identified 7 studies that included 9280 children and adolescents (49% girls) aged 8-19 years from 14 countries. Cardiovascular disease risk was already present in boys (6-39%) and girls (6-86%). Boys with low fitness (<41.8 mL/kg/min) had a 5.7 times greater likelihood of having cardiovascular disease risk (95% CI 4.8 to 6.7). The comparable diagnostic OR for girls with low fitness (<34.6 mL/kg/min) was 3.6 (95% CI 3.0 to 4.3). The 95% confidence region of cardiorespiratory fitness associated with low cardiovascular disease risk ranges, 41.8-47.0 mL/kg/min in boys (eg, stages 6-8 for a boy aged 15 years) and 34.6-39.5 mL/kg/min in girls (eg, stages 3-5 for a girl aged 15 years). The cardiorespiratory fitness cut point to avoid cardiovascular disease risk ranged 41.8 mL/kg/min in boys and was 34.6 mL/kg/min in girls. SUMMARY: Fitness levels below 42 and 35 mL/kg/min for boys and girls, respectively, should raise a red flag. These translate to 6 and 3 stages on the shuttle run test for a boy and a girl, both aged 15 years, respectively. These cut points identify children and adolescents who may benefit from primary and secondary cardiovascular prevention programming.

Intervention effects on dietary intake among children by maternal education level: results of the Copenhagen School Child Intervention Study (CoSCIS).

Dietary intake among Danish children, in general, does not comply with the official recommendations. The objectives of the present study were to evaluate the 3-year effect of a multi-component school-based intervention on nutrient intake in children, and to examine whether an intervention effect depended on maternal education level. A total of 307 children (intervention group: n 184; comparison group: n 123) were included in the present study. All had information on dietary intake pre- and post-intervention (mean age 6·8 and 9·5 years for intervention and comparison groups, respectively) assessed by a 7-d food record. Analyses were conducted based on the daily intake of macronutrients (energy percentage (E%)), fatty acids (E%), added sugar (E%) and dietary fibre (g/d and g/MJ). Analyses were stratified by maternal education level into three categories. Changes in nutrient intake were observed in the intervention group, mainly among children of mothers with a short education ( < 10 years). Here, intake of dietary fibre increased (ß = 2·1 g/d, 95 % CI 0·5, 3·6, P= 0·01). Intake of protein tended to increase (ß = 0·6 E%, 95 % CI -0·01, 1·2, P= 0·05), while intake of fat (ß = -1·7 E%, 95 % CI -3·8, 0·3, P= 0·09) and SFA (ß = -0·9, 95 % CI -2·0, 0·2, P= 0·10) tended to decrease. Also, a significant intervention effect was observed on the intake of SFA among children of mothers with a long education (ß = -0·8, 95 % CI -1·5, -0·03, P= 0·04). This multi-component school-based intervention resulted in changes in the dietary intake, particularly among children of mothers with a short education. As the dietary intake of this subgroup generally differs most from the recommendations, the results of the present study are particularly encouraging.

Mid-regional pro-atrial natriuretic peptide and blood pressure in adolescents: effect of gender and pubertal stage.

Little is known about blood pressure in relation to circulating natriuretic peptide concentrations and gender in generally healthy adolescents. We studied 15-year-old females and males (n = 335) from the Danish site of the European Youth Heart Study (EYHS). Blood pressure was measured using a standardized protocol, sexual maturity was assessed according to Tanner stage, and as a surrogate for atrial natriuretic peptide, we measured mid-regional pro-atrial natriuretic peptide (MR-proANP) in plasma. Compared with boys, girls had lower systolic blood pressure (SBP) (mean ± SD: 109.6 ± 9.9 mmHg vs 116.9 ± 11.4 mmHg, p < 0.0001) and higher plasma MR-proANP concentrations [median (interquartile range): 42.1 pmol/l (31.9-50.2 pmol/l) vs 36.6 pmol/l (30.6-44.9 pmol/l), p = 0.0046]. When female adolescents were further subdivided according to Tanner stage, there were no differences in blood pressure and plasma MR-proANP concentrations between post-pubertal and pubertal girls (p > 0.17). In contrast, after similar subdivision, post-pubertal boys had higher SBP (mean ± SD: 117.7 ± 11.7 mmHg vs 111.4 ± 7.9 mmHg, p = 0.029) and lower plasma MR-proANP concentrations [median (interquartile range): 36.2 pmol/l (30.6-43.1 pmol/l) vs 46.4 pmol/l (30.3-51.1 pmol/l), p = 0.043] compared with pubertal boys. Given their higher SBP, boys had lower than expected plasma concentrations of MR-proANP compared with girls, and given their higher SBP, post-pubertal boys had lower than expected plasma concentrations of MR-proANP compared with pubertal boys.

Six physical education lessons a week can reduce cardiovascular risk in school children aged 6-13 years: a longitudinal study.

AIMS: Cardiovascular disease (CVD) originates during childhood and adolescence. Schools are potentially effective settings for early public health prevention strategies. The aim of this study was to evaluate the effect of six physical education (PE) lessons on children's CVD risk. METHODS: This longitudinal study in 10 public schools (1218 children, aged 6-13 years), 6 intervention and 4 control schools evaluates a natural experiment, where intervention schools tripled PE to six lessons per week compared to the mandatory two PE lessons in the control schools. Baseline (2008) and 2-year follow-up measures were anthropometrics, cardiorespiratory fitness, blood pressure and blood samples providing lipids and measures for insulin resistance. Based on these variables, a composite risk score was calculated and used for further analysis. Multivariate multilevel mixed effect regression models were used to estimate effect of intervention taking the hierarchical structure of data into account. Individual, class and school were considered random effects. Intra class correlation (ICC) was calculated. RESULTS: Intervention significantly lowered mean of composite risk score with 0.17 SD (95% CI: -0.34 to -0.01). Six PE lessons per week had a beneficial effect on triglycerides (TG) levels (-0.18 SD, 95% CI: -0.36 to 0.00), systolic blood pressure (SBP) (-0.22 SD, 95% CI: -0.42 to -0.02) and insulin resistance (HOMA-IR) (-0.17 SD, 95% CI: -0.34 to 0.01). CONCLUSIONS: Six PE lessons at school can reduce children's CVD risk measured as a composite risk score. The changes in risk score are considered substantial in the perspective of public health strategy for preventing CVD in later life.

Aerobic fitness after JDM--a long-term follow-up study.

OBJECTIVES: It has previously been shown that patients with active JDM have decreased aerobic fitness; however, it is not known whether these patients regain their physical fitness after recovery. The objective of this study was to investigate the long-term outcome of aerobic fitness in patients with JDM. We hypothesized that fitness (VO(2max)) is reduced compared with healthy controls in the years after active JDM. METHODS: A maximal exercise test was performed using a cycle ergometer. Results were compared with those of sex- and age-matched healthy controls. RESULTS: A total of 36 patients with JDM in remission were included, 2-36 years after disease onset. Twelve patients (33%) had normal VO(2max) and 24 patients (67%) had decreased VO(2max). Mean VO(2max) was higher in the healthy controls vs patients (P < 0.001, 95% CI -10.7, -4.4). A significant difference between patients with JDM and controls was observed for women (P < 0.001), men (P = 0.04), children < 18 years (P = 0.002) and adults > 18 years (P = 0.01). The decreased VO(2max) was independent of the duration of remission, but it was associated with the duration of active disease. By linear regression, it was revealed that for every year of active disease, VO(2max) was reduced by 0.85 ml/min/kg on average (P < 0.001). CONCLUSION: This long-term follow-up study demonstrates that patients who have had JDM have persistently impaired fitness. This impairment is directly related to the duration of active disease.