Decline in physical fitness from childhood to adulthood associated with increased obesity and insulin resistance in adults

Study on the relationship and related factors between physical fitness and health behavior of preschool children in southwest China

OBJECTIVE

To investigate the physical fitness level and health behavior status of preschool children in China, explore the relationship between physical fitness and health behavior, and further reveal the main factors affecting health behavior, to provide a reference for improving the physical fitness level of preschool children and maintaining healthy behavior.

METHODS

A total of 755 preschool children (394 boys and 361 girls, aged 4.52 ± 1.11 years) were selected from Chongqing and Liupanshui in China by cluster random sampling method for questionnaire survey and physical monitoring, and SPSS21.0 software was used to process and analyze the data.

RESULTS

(1) Heart rate (p = 0.015), protein content (p < 0.001), and time spent on the balance beam (p < 0.001) were significantly lower in boys than in girls, while BMI (p = 0.012), muscle mass (p < 0.001), and distance of standing long jump (p < 0.001) were significantly higher in boys than in girls. Meanwhile, systolic blood pressure (p = 0.004) and diastolic blood pressure (p = 0.001) of rural children were significantly higher than those of urban children, while BMI (p < 0.001) and sitting forward flexion (p = 0.019) were significantly lower than those of urban children. (2) The light-intensity physical activity (LPA) and moderate to vigorous physical activity (MVPA) of boys were significantly higher than that of girls (p < 0.001), and the MVPA of urban children was significantly higher than that of rural children (p = 0.001), and the former participated in sports classes more frequently (p < 0.001). (3) There was a significant correlation between physical activity (PA) and physical fitness indicators of preschoolers. Participating in sports interest classes was only significantly correlated with systolic blood pressure (r = 0.08) and sitting forward flexion (r = 0.09). (4) The PA level of preschool children was related to gender, household registration, kindergarten nature, age, residence environment, parental support, and participation degree. Participation in sports interest classes was related to gender, the nature of the kindergarten, household registration, age, and parent participation. Daily screen time was related to household registration, the nature of the kindergarten, the environment of residence, and the value perception of parents.

CONCLUSIONS

There were different degrees of correlation between preschool children's physical fitness and health behaviors, and children's health behaviors were closely related to gender, environment, parents, and other factors. Therefore, how to increase the protective factors of children's health behaviors and controlling the risk factors may be crucial to promoting the development of good health behaviors and improving the physical fitness of preschool children.

Tracking of Cardiorespiratory Fitness from Childhood to Mid-adulthood

High cardiorespiratory fitness (CRF) in adulthood is important for survival from major chronic diseases and preserving good health. We examined how childhood CRF tracks, or persists, into adulthood. Among a cohort of 748 school children followed over 34 years, we found child CRF correlated with young- (r = 0.30) and mid-adulthood (r = 0.16) CRF.

Physical Activity Is Associated with Physical Fitness and Executive Function among School Children in the Jiangxi Region of China

Previous studies have suggested that a positive relationship exists between physical activity (PA), physical fitness, and cognitive function in children and adolescents. However, research remains limited on the relationship among these three variables in Chinese individuals not living in big cities or specific regions. Therefore, this study investigated the association of PA with physical fitness and cognitive function (specifically, executive function) among 1100 children aged 9-12 years living in the Jiangxi region of China. Participants' PA levels were measured using the PA questionnaire for older children. Physical fitness was assessed based on cardiorespiratory endurance, muscle strength, muscular endurance, flexibility, and body mass index (BMI). Executive function was assessed using the Behavior Rating in Inventory of Executive Function questionnaire. Data were analyzed using one-way analyses of variance, Scheffé tests, one-way analyses of covariance, and Pearson's correlation coefficients. The results showed that PA is significantly associated (p < 0.01) with cardiorespiratory endurance (r = 0.460), muscular endurance (r = 0.270), muscle strength (r = 0.190), BMI (r = -0.114), and executive function (r = -0.140). Moreover, all components of physical fitness and executive function differed significantly based on PA level, with and without age and sex as covariates (p < 0.05). Overall, our results highlight the importance of higher PA levels during childhood to improve physical fitness and cognitive function. Including the goal of improving health-related fitness factors, such as cardiorespiratory endurance and muscle strength, is particularly important in PA programs for children.

A cohort study of factors influencing the physical fitness of preschool children: a decision tree analysis

Objective

Based on the decision tree model, to explore the key influencing factors of children's physical fitness, rank the key influencing factors, and explain the complex interaction between the influencing factors.

Methods

A cohort study design was adopted. 1,276 children (ages 3-6) from 23 kindergartens in Nanchang, China, were chosen for the study to measure the children's physical fitness at baseline and a year later and to compare the physical fitness scores at the two stages. The study was conducted following the Chinese National Physical Fitness Testing Standard (Children Part); To identify the primary influencing factors of changes in physical fitness, a decision tree model was developed, and a questionnaire survey on birth information, feeding patterns, SB, PA, dietary nutrition, sleep, parental factors, and other relevant information was conducted.

Results

The levels of physical fitness indicators among preschool children showed a significant increase after 1 year. The accuracy of the CHAID model is 84.17%. It showed that 7 variables were strongly correlated with the physical changes of children's fitness, the order of importance of each variable was weekend PA, weekend MVPA, mother's BMI, mother's sports frequency, father's education, mother's education, and school day PA. Three factors are related to PA. Four factors are related to parental circumstances. In addition to the seven important variables mentioned, variables such as breakfast frequency on school day, puffed food, frequency of outing, school day MVPA, parental feeling of sports, father's occupation, and weekend breakfast frequency are all statistically significant leaf node variables.

Conclusion

PA, especially weekend PA, is the most critical factor in children's physical fitness improvement and the weekend MVPA should be increased to more than 30 min/d based on the improvement of weekend PA. In addition, parental factors and school day PA are also important in making decisions about changes in fitness for children. The mother's efforts to maintain a healthy BMI and engage in regular physical activity are crucial for enhancing the physical fitness of children. Additionally, other parental factors, such as the parents' educational levels and the father's occupation, can indirectly impact the level of physical fitness in children.

Comparative effectiveness of school-based exercise interventions on physical fitness in children and adolescents: a systematic review and network meta-analysis

Background

Schools provide a favorable setting for health education, however, the most effective school-based exercise mode for improving physical fitness remains unclear. This network meta-analysis was designed to assess and rank the comparative efficacy of six exercise modalities on physical fitness indicators in a school-based setting.

Methods

An online search of the Web of Science, PubMed, SPORTDiscus, and Scopus databases was conducted. Randomized and quasi-randomized controlled trials were considered. Outcomes included measures of anthropometry and body composition, muscular fitness, and cardiorespiratory fitness. Data were pooled with a random effects model using the frequentist framework.

Results

A total of 66 studies with 8,578 participants (48% girls) were included. High-intensity interval training was the most effective intervention reducing body mass index (mean difference (MD) = -0.60 kg·m^-2, 95% confidence interval (95%CI) = -1.04 to -0.15, p = 0.009), elevating VO_2max (MD = 3.59 mL·kg^-1·min^-1, 95% CI = 2.45 to 4.74, p < 0.001), and 20-meter sprint performance (MD = -0.35 s, 95% CI = -0.55 to -0.14, p = 0.001). Aerobic training had the highest probability of reducing waist circumference (standardized mean difference (SMD) = -0.60, 95% CI = -0.88 to -0.32, p < 0.001). Active video games emerged as a promising modality for improving countermovement jump (MD = 2.43 cm, 95% CI = 0.06 to 4.80, p = 0.041) and shuttle running performance (SMD = 0.86, 95% CI = 0.29 to 1.43, p = 0.003). Strength training was the best exercise mode for improving standing long jump performance (SMD = 1.03, 95% CI = 0.07 to 1.98, p = 0.035) while combined training was rated the first for decreasing body fat percent (MD = -2.56%, 95% CI = -4.73 to -0.40, p = 0.022) and increasing push-up repetitions (SMD = 3.59, 95% CI = 0.81 to 6.37, p = 0.012).

Conclusion

School-based exercise interventions have multiple effects on physical fitness. The findings of this study will help to inform physical education teachers and coaches how best to deliver exercise programs in a school setting. Since the study was limited by the original research, the conclusions will require further verification using high-quality randomized controlled trials.

Systematic Review Registration

PROSPERO, Identifier: CRD42023401963.

Temporal trends in physical fitness among Chinese children and adolescents from 2000 to 2019 and analysis of social-ecological factors

This study aimed to estimate temporal trends in physical fitness (PF) by regions, age groups and nutritional status among Chinese children and adolescents and to longitudinally examine PF determinants based on social-ecological model. Participants (n = 68,265) aged 7-18 were from five successive national surveys (2000 to 2019). Six tested items of PF were calculated as PF indicator (PFI), which was used to divide participants into two categories: low vs. moderate/high. One-way analysis of variance was used to compare difference and change trend of PFI. Linear regression evaluated relationship between PFI and body mass index (BMI), and logistic regression assessed association between PFI and factors of behaviours and lifestyles on individual-, family- and school-level based on the social-ecological model. PFI declined sharply from 2000 to 2010, increased slightly from 2010 to 2014 and then edged down in 2019. Students with moderate BMI and students in urban areas tended to have higher PFI, and larger increase of PFI was found in students aged 7-9 and 13-15 after 2010. Several determinants on individual-, family- and school-level related to PFI. Efforts to develop PF mainly include increasing PA and reducing sedentary behaviours by facilitating home-school collaboration and emphasizing age-, region- and BMI-specific actions.

Trend in health-related physical fitness for Chinese male first-year college students: 2013-2019

Introduction

Physical fitness is a health indicator contributing to the prevention of non-communicable diseases that threaten public health. Studies across a number of global populations indicate that physical fitness is generally declining. This study investigated the trend in physical fitness of Chinese male first-year college students from 2013 to 2019 to offer critical information for fostering individual and public health.

Methods

This study used archival data and a natural experiment design capturing 4 years of data prior to implementation of the Healthy China 2030 initiative and 3 years following. Physical fitness tests were based on the Chinese national student physical fitness standards for males including body mass index, vital capacity, standing-long-jump, sit-and-reach, pull-ups, 50 m sprint, and 1,000 m run. Because the physical fitness tests set different standards for males and females, female data will be reported separately. Data from a total of 3,185 Chinese male first-year college students from a private university in Hebei Province of China were included in the study. A one-way multivariate analysis of variance was used for analyzing the research data.

Results

The results indicated an overall significant difference in health-related physical fitness of Chinese male first-year college students, with scores on health indicators generally declining from 2013 to 2019. Despite improvement on some fitness variables in some years, performance on virtually all indicators was diminished compared to baseline years.

Discussion

These findings can contribute to the existing global literature in the field of public health showing general declines in physical fitness. Chinese universities have the opportunity to support Healthy China 2030 goals and cultivate individuals' physical fitness by offering physical education course that encourage college students to participate in moderate-to-vigorous-intensity physical activities in order to support physical fitness development.

Tracking of physical fitness levels from childhood and adolescence to adulthood: a systematic review and meta-analysis

BACKGROUND

Prospective and large studies indicate that high physical fitness levels during young are beneficial for health during adulthood. The aim of the study was to investigate the tracking of physical fitness components from childhood and/or adolescence to adulthood.

METHODS

Two authors systematically searched MEDLINE and Web of Science electronic databases for relevant articles. Studies with apparently healthy youth aged 6-18 years who track their physical fitness to adulthood were included. Our study carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Correlation coefficients (r) were used as effect size. Random-effects models were used to estimate the pooled effect size. Correlation coefficients were interpreted as follows: <0.30 low stability, 0.30 to 0.60 moderate stability, and >0.60 high stability. Risk of bias of each study was determined by The Quality Assessment Tool for Observational Cohort and Cross-sectional Studies.

RESULTS

Twenty-one prospective studies were included in the meta-analysis (n=6,197 participants at follow-up, 47.4% women). The mean length of follow-up was 20.8 years. Overall, cardiorespiratory fitness (r=0.38; 95% CI: 0.29-0.48; I²=92.7%), muscular strength (r=0.51; 95% CI: 0.43-0.59; I²=87.9%), and muscular endurance (r=0.50; 95% CI: 0.36-0.86; I²=94.5%) show moderate tracking from childhood and/or adolescence to adulthood, independent of test used and length of follow-up. This moderate tracking was slightly stronger in women than in men and from adolescence compared to childhood. Trunk flexibility component, assessed with the sit and reach test, exhibits high stability (r=0.69; 95% CI: 0.58-0.81; I²=92.9%). Interestingly, meta-regression analysis shows positive association between correlation coefficient for flexibility and the length of follow-up (β =0.017; 95% CI: 0.012-0.021).

DISCUSSION

Although the current study found inconsistency between results, the findings suggest that acquiring high physical fitness levels should be targeted already from childhood and adolescence given that low levels of fitness in adulthood are related with several chronic diseases and mortality.

TRIAL REGISTRATION

Registration number CRD42021279143.

A Systematic Review of the Effects of Physical Activity on Specific Academic Skills of School Students

This systematic review examined the effects of distinct physical activity interventions on the academic achievement of school students based on an analysis of four distinct outcomes: mathematics, language, reading, and composite scores. This study was performed in accordance with the PRISMA guidelines and the QUORUM statement. A literature search was conducted using the PubMed-MEDLINE, Scopus, and Web of Science databases. Peer-reviewed studies published in English, Portuguese, and Spanish were considered. A random-effect meta-analysis was employed to determine the effect of interventions on academic performance. The effects between interventions and control groups were expressed as standardized mean differences. Thirty-one studies were included in the meta-analysis based on the inclusion and exclusion criteria. The exercise programs were not capable of significantly improving language, reading skills, and composite scores. Conversely, performance in math tests increased significantly after the interventions compared with the control groups. Regarding the overall effect, a significant improvement in academic achievement was detected after physical activity programs compared with controls. In conclusion, the positive effects of school-based physical education on academic performance are not uniform and may be higher for math skills. The implementation of evidence-based exercise programs in school settings emerges as a promising strategy to increase overall academic achievement in school-aged students.

Insufficient Physical Fitness and Deficits in Basic Eating Habits in Normal-Weight Obese Children Are Apparent from Pre-School Age or Sooner

Normal-weight obesity appears to be an extended diagnosis/syndrome associated with insufficient physical fitness levels and inadequate eating habits at least from school years. However, its relation to long term health parameters in pre-school children remains unknown, even though pre-school age is crucial for the determining healthy lifelong habits. Therefore, the aim of the current study was to investigate the differences in physical fitness level and basic eating habits between normal-weight obese, normal-weight non-obese, and overweight and obese preschoolers. The research sample consisted of 188 preschoolers aged 4.0–6.9 years (M_age = 5.52 ± 0.8 year), normal-weight obese = 25; normal-weight non-obese = 143, overweight and obese = 20. Body composition was measured using bio-impedance InBody230. Six tests assessed the physical fitness level: sit-ups; standing long jump; shuttle running 4 × 5 meters; throwing with a tennis ball; multistage fitness tests; sit and reach. A four-item eating habits questionnaire for parents focusing on breakfast regularity, consumption of sweet foods and drinks, selection of food and attitude towards eating was used. A non-parametric analysis of variance and Fisher’s exact test along with suitable effect sizes were used for data processing of physical fitness tests and the basic eating habits questionnaire, respectively. Normal-weight obese children performed significantly worse (from p = 0.03 to p < 0.001, ES ω2-G = low to medium) in muscular fitness, cardiorespiratory fitness and running agility compared to normal-weight non-obese counterparts and did not significantly differ in the majority of physical fitness performance tests from overweight and obese peers. In basic eating habits, normal-weight obese boys preferred significantly more sweet foods and drinks (p = 0.003 ES = 0.35, large), while normal-weight obese girls had significantly more negative attitude towards eating (p = 0.002 ES = 0.33, large) in comparison to their normal-weight non-obese peers. Normal-weight obesity seems to develop from early childhood and is associated with low physical fitness and deficits in eating habits which might inhibit the natural necessity for physically active life from pre-school age or sooner.

The Cardiorespiratory fitness of children and adolescents in Tibet at altitudes over 3,500 meters

BACKGROUND

Cardiorespiratory fitness (CRF) is the core element of health-related physical fitness evaluation. High pressure and low oxygen in Tibet (over 3,500 m above sea level) may negatively impact the residents' CRF. The 20-m shuttle run test (20mSRT) is the most popular field-based assessment and estimate of CRF in children and adolescents worldwide. However, normative CRF data for the children and adolescents residing in China's plateau region are unavailable, which prevents comparability among those living at high-altitudes around the world.

PURPOSE

To measure the CRF of Chinese children and adolescents aged 9-18 years living in Tibet at altitudes exceeding 3,500 m, and to identify correlations between this metric and demographic characteristics (age, sex, and ethnicity). These data were then compared with those generated in the lowland (Shanghai, China) and various global regions.

METHODS

20mSRT performance (number of completed laps) and predicted peak oxygen consumption (VO2peak) were used as indicators of CRF. We measured the CRF of 1,717 healthy children and adolescents aged 9-18 years living in Tibet. The CRF data from school-age subjects in Shanghai (2,437 boys and 2,396 girls) and worldwide (1,142,026 students from 50 countries/regions in Africa, Asia, Europe, Latin America, North America, and Oceania) were collated from published papers.

RESULTS

The average CRF of the participants from Tibet was 39.8 mL/kg/min. The male subjects (n = 876; 41.1 ± 4.42 mL/kg/min) had a higher average CRF than their female counterparts (n = 841; 37.8 ± 5.40 mL/kg/min). CRF decreased with age in both sexes at statistical significance (F = 1249.9, p for trend 0.05). The indigenous Tibetans (n = 1289; 40.1 ± 3.71 mL/kg/min) had a significant higher average CRF than those of Han descent (n = 394; 38.9 ± 4.70 mL/kg/min) (p < 0.05).

CONCLUSIONS

Children and adolescents aged 7-18 years residing above 3,500 m in Tibet displayed lower CRF traits compared with their counterparts from the plains area and other high altitude places. CRF varied according to age, sex, and ethnic group. Given the importance of CRF in children and adolescents, effective intervention strategies should be implemented to improve CRF in children and adolescents on the plateau.

Can Anthropometry and Body Composition Explain Physical Fitness Levels in School-Aged Children?

Physical fitness (PF) is closely related to various health outcomes and quality of life among children. However, the associations between anthropometry, body composition (BC), and PF are not fully elucidated. This cross-sectional study aimed to investigate the associations between demographic metrics (age, sex), anthropometric measures (body mass index z-score (BMI z-score) waist/height ratio (WHtR)), BC parameters (body-fat percentage (BF%), muscle weight), and PF levels (800-m run, sit-and-reach, 1-min sit-ups, standing long jump) in school-aged children. Continuous variables were dichotomized by median splits. The results of 180 girls and 180 boys (mean age: 10.0 ± 0.7 years; mean BMI z-score: 0.366 ± 1.216) were analyzed. Multivariable linear regressions revealed that BF% (regression coefficient (B) = 3.4, 95% confidence interval (CI) = 2.5-4.3) was independently correlated with the 800-m run. Sex (B = 4.6, 95% CI = 3.0-6.3), age (B = 3.1, 95% CI = 1.9-4.3), and BMI z-score (B = -0.7, 95% CI = -1.4--0.1) were independently related to sit-and-reach. Age (B = 3.3, 95% CI = 2.0-4.7), BF% (B = -0.3, 95% CI = -0.4--0.2), and muscle weight (B = 0.7, 95% CI = 0.2-1.2) were independently associated with 1-min sit-ups. In addition to demography, anthropometry and BC provided additional information concerning some PF levels in school-aged children. Weight management and PF promotion should be addressed simultaneously in terms of preventive medicine and health promotion for children.

Functional endurance capacity is associated with multiple other physical fitness components in 7-14-year-olds: a cross-sectional study

Background

Although evidence suggests that functional endurance capacity is the most important component associated with future health, little is known of how it is associated with multiple other physical fitness components. Since various physical fitness aspects do not change the same as functional endurance capacity during childhood, it is necessary to establish possible associations between functional endurance capacity and other physical fitness components in children. Therefore, the main purpose of the study was to test the associations between functional endurance capacity with other physical fitness components in 7–14-year-old children, stratified by gender.

Methods

In this cross-sectional study, we recruited 1612 children [mean age ± standard deviation (SD) = 9.72 ± 2.37 years; 52.5% girls). Health-related physical fitness components included: 1) body-mass index (kg/m²) calculated from height and weight (measure of body size), 2) sit-and-reach test (measure of flexibility), 3) standing broad jump (measure of explosive strength of lower extremities), 4) sit-ups in 30 s (measure of repetitive strength of the trunk), 5) 10 × 5 shuttle run test (measure of agility) and 6) 20-m shuttle run test (measure of functional endurance capacity). The associations were performed using generalized estimating equations with beta (β) coefficients.

Results

After adjusting for age, functional endurance capacity was associated with sit-and-reach test (β = 0.13, p < 0.001), standing broad jump (β = 0.59, p < 0.001), sit-ups in 30 s (β = 0.53, p < 0.001) and 10 × 5 shuttle run test (β = − 0.56, p < 0.001) in boys. In girls, functional endurance capacity was associated with body-mass index (β = − 0.12, p < 0.001), sit-and-reach test (β = 0.21, p < 0.001), standing broad jump (β = 0.25, p < 0.001), sit-ups in 30 s (β = 0.36, p < 0.001) and 10 × 5 shuttle run test (β = − 0.40, p < 0.001). No significant associations between functional endurance capacity and body-mass index in boys were observed.

Conclusions

Although significant, functional endurance capacity is weakly to moderately associated with other physical fitness components, pointing out that such measure should be tested separately from other aspects of physical fitness in school-aged children.

Physical Fitness and Motor Competence in Upper Austrian Elementary School Children-Study Protocol and Preliminary Findings of a State-Wide Fitness Testing Program

Motor competence and physical fitness are key components for the promotion of an active and healthy lifestyle. Poor motor competence and low physical fitness in children, therefore, are a major threat to future public health. Even though the assessment of physical fitness and motor competence per se does not enhance these entities, fitness tests can provide important information for intervention strategies. Fitness tests may also motivate children to become more active in order to increase their physical abilities. In the school-year 2016/17 the Upper Austrian government initiated the state-wide testing program "wie fit bist du" (how fit are you) in elementary schools, that examined cardiorespiratory fitness, muscular power, speed, agility, flexibility and object control skills along with the assessment of height and weight. Since the beginning of the program more than 18,000 children between 6 and 11 years of age participated in the school-based tests. The results show a significant increase in the prevalence of overweight/obesity with increasing age (p > 0.01). Overweight/obese children displayed lower motor competence and physical fitness, except for upper body strength. Further, the improvement in test performance with increasing age was less pronounced in overweight/obese children compared to their normal weight peers. In fact, distance covered during the 6-min run did not improve throughout the elementary school years in overweight/obese children. Given the importance of motor competence and physical fitness for general development and well-being, physical education should be considered a viable setting for the promotion of these entities as a majority of children can be reached independent of their socio-economic background. In order to provide adequate movement experiences that enhance motor competence and physical fitness while ensuring a motivating environment, objective information on current ability levels are required. The implementation of fitness monitoring at young ages, therefore, can be an important contributor for the promotion of an active and healthy lifestyle.

Individual Physical Activity Behaviour and Group Composition as Determinants of the Effectiveness of a Childhood Obesity Intervention Program

INTRODUCTION

Up to now, there is limited clarity on factors that determine the effectiveness of childhood obesity interventions.

OBJECTIVE

This study intends to uncover individual- and program-level predictors of BMI-SDS and fitness to achieve significant, sustainable health improvements.

METHODS

Data of 249 children with obesity or overweight who participated in an outpatient multidisciplinary program were analysed and compared to 54 waitlist controls. Linear regression models were used to examine associations between individual- and group-level variables and BMI-SDS and fitness.

RESULTS

Among intervention children, BMI-SDS decreased by 0.19 units and physical fitness increased by 11.5%, versus a BMI-SDS decrease of 0.07 and a 1.8% decrease in fitness in the control group. Participants who reported being physically active before the program start achieved greater improvements in BMI-SDS (β = -0.177, p < 0.05) and physical fitness (β = 0.174, p < 0.05) than inactive peers. BMI-SDS decreased significantly more for members of gender-heterogeneous groups (β = 0.194, p < 0.05) with a narrow age range (β = 0.152, p < 0.05).

CONCLUSIONS

The program under review is effective in counteracting juvenile obesity. The results give reason to believe that forming mixed-gender groups with a small age range and providing increased support for reportedly inactive children may improve program effectiveness.

Screening for Hypertension in Children and Adolescents: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Childhood hypertension can result in adverse outcomes during adulthood; identifying and treating primary and secondary childhood hypertension may reduce such risks.

OBJECTIVE

To update the evidence on screening and treatment of hypertension in childhood and adolescence for the US Preventive Services Task Force.

DATA SOURCES

PubMed, Cochrane Library, International Pharmaceutical Abstracts, EMBASE, and trial registries through September 3, 2019; bibliographies from retrieved articles, experts, and surveillance of the literature through October 6, 2020.

STUDY SELECTION

Fair- or good-quality English-language studies evaluating diagnostic accuracy of blood pressure screening; cohort studies assessing the association of hypertension in childhood and adolescence with blood pressure or other intermediate outcomes in adulthood; randomized clinical trials (RCTs) or meta-analyses of pharmacological and lifestyle interventions.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently assessed titles/abstracts and full-text articles, extracted data, and assessed study quality; the evidence was synthesized qualitatively.

MAIN OUTCOMES AND MEASURES

Sensitivity, specificity, and measures of association between childhood and adulthood blood pressure; reduction of childhood blood pressure; adverse effects of treatments.

RESULTS

Forty-two studies from 43 publications were included (N>12 400). No studies evaluated the benefits or harms of screening and the effect of treating childhood hypertension on outcomes in adulthood. One study reported a sensitivity of 0.82 and a specificity of 0.70 for 2 office-based blood pressure measurements. Twenty observational studies suggested a significant association between childhood hypertension and abnormal blood pressure in adulthood (odds ratios, 1.1-4.5; risk ratios, 1.45-3.60; hazard ratios, 2.8-3.2). Thirteen placebo-controlled RCTs and 1 meta-analysis assessed reductions in systolic (SBP) and diastolic blood pressure from pharmacological treatments. Pooled reductions of SBP were -4.38 mm Hg (95% CI, -7.27 to -2.16) for angiotensin-converting enzyme inhibitors and -3.07 mm Hg (95% CI, -4.99 to -1.44) for angiotensin receptor blockers. Candesartan reduced SBP by -6.56 mm Hg (P < .001; n = 240). β-Blockers, calcium channel blockers, and mineralocorticoid receptor antagonists did not achieve significant reductions over 2 to 4 weeks. SBP was significantly reduced by exercise over 8 months (-4.9 mm Hg, P ≤ .05; n = 69), by dietary approaches to stop hypertension over 3 months (-2.2 mm Hg, P < .01; n = 57), and by a combination of drug treatment and lifestyle interventions over 6 months (-7.6 mm Hg; P < .001; n = 95). Low-salt diet did not achieve reductions of blood pressure.

CONCLUSIONS AND RELEVANCE

Observational studies indicate an association between hypertension in childhood and hypertension in adulthood. However, the evidence is inconclusive whether the diagnostic accuracy of blood pressure measurements is adequate for screening asymptomatic children and adolescents in primary care.

Cardiorespiratory fitness is positively associated with both healthy and western dietary pattern in Iranian middle-aged

Background: The association between dietary patterns and cardiorespiratory fitness (CRF) is not well established. Objective: We sought to investigate association between a posteriori dietary pattern and CRF in middle-aged adults. Design: Adults (n = 276), aged 20-74 years, who were residents of Tehran, Iran were recruited. Diet was assessed by using a validated 168-item semi-quantitative food frequency questionnaire. Principal component analysis was used to derive dietary patterns. Socio-economic status, anthropometric measures, body composition, and blood pressure were recorded. CRF was assessed by using a graded exercise treadmill test. Analysis of variance and linear regression models were used to discern the association between dietary patterns and CRF. Results: Higher scores of the healthy dietary pattern had no association with VO_2max (p = 0.13). After controlling for potential confounders, VO_2max was positively associated across tertiles of healthy dietary patterns (p < 0.001). Higher adherence to the "mixed" dietary pattern was inversely related to VO_2max (p < 0.01). After adjusting for confounders, the significant association disappeared (p = 0.14). Higher scores of the "Western" dietary pattern was not associated with VO_2max (p = 0.06). However, after controlling for potential confounders, VO_2max was positively associated with the "Western" dietary pattern (p = 0.01). A positive linear association between the "healthy" dietary pattern and CRF for the total sample (R² = 0.02; p < 0.01) were presented. Conclusions: Overall, our findings suggest that higher adherence to a "healthy" and "Western" dietary pattern was positively associated with CRF. However, further studies are required to examine and clarify the causal relationship between dietary patterns and CRF.

Physical Activity Space Methodology for Assessment and Prioritization (PASMAP): Combining systematic observations with community perceptions to identify community physical activity resource priorities

Despite benefits of physical activity (PA), most Americans are not regularly active, with notable disparities for residents of low-income communities. PA is positively correlated with resource availability and quality, which can be measured and quantified by PA resource assessment tools. However, community members' perceptions are often not considered. This study incorporates community perceptions with systematic environmental observations to identify community PA resource priorities. The PA Space Methodology for Assessment and Prioritization (PASMAP) includes three phases. Phase 1: Promotora-researchers completed 57 PA Resource Assessments (PARAs) in colonias along the Texas-Mexico border assessing quantity and quality of features, amenities, and incivilities. Characteristics were ranked using average PARA scores from all PA spaces. Phase 2: community advisory board (CAB) members (n = 36 from 3 CABs) ranked the importance of each feature, amenity, and incivility respectively; rankings were averaged and ordered. Phase 3: differences between phases 1 and 2 were calculated. Large differences indicated high discordance between systematic observations and perceived importance. Phase 1: highest ranked PARA characteristics were sidewalks, non-street lighting, and noise. Phase 2: CAB members ranked trails/paths, sidewalks, play equipment, bathrooms, drinking fountains, substance abuse evidence, and litter most important. Phase 3: multiple characteristics had high discordance: trails/paths, fenced-in open fields (features), drinking fountains (amenity), and litter (incivility); low quantity/poor quality yet perceived as highly important. Discordant characteristics identified through PASMAP provide evidence-based, community-valued recommendations on PA resource priorities for planning and advocacy. Future work should incorporate perceptions from additional community members and apply PASMAP methods to other environmental assessments.

Association of Cardiorespiratory Fitness Levels During Youth With Health Risk Later in Life: A Systematic Review and Meta-analysis

IMPORTANCE

Although the associations between cardiorespiratory fitness (CRF) and health in adults are well understood, to date, no systematic review has quantitatively examined the association between CRF during youth and health parameters later in life.

OBJECTIVES

To examine the prospective association between CRF in childhood and adolescence and future health status and to assess whether changes in CRF are associated with future health status at least 1 year later.

DATA SOURCES

For this systematic review and meta-analysis, MEDLINE, Embase, and SPORTDiscus electronic databases were searched for relevant articles published from database inception to January 30, 2020.

STUDY SELECTION

The following inclusion criteria were used: CRF measured using a validated test and assessed at baseline and/or its change from baseline to the end of follow-up, healthy population with a mean age of 3 to 18 years at baseline, and prospective cohort design with a follow-up period of at least 1 year.

DATA EXTRACTION AND SYNTHESIS

Data were processed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Random-effects models were used to estimate the pooled effect size.

MAIN OUTCOMES AND MEASURES

Anthropometric and adiposity measurements and cardiometabolic health parameters.

RESULTS

Fifty-five studies were included with a total of 37 563 youths (46% female). Weak-moderate associations were found between CRF at baseline and body mass index (r = -0.11; 95% CI, -0.18 to -0.04; I2 = 59.03), waist circumference (r = -0.29; 95% CI, -0.42 to -0.14; I2 = 69.42), skinfold thickness (r = -0.34; 95% CI, -0.41 to -0.26; I2 = 83.87), obesity (r = -0.15; 95% CI, -0.23 to -0.06; I2 = 86.75), total cholesterol level (r = -0.12; 95% CI, -0.19 to -0.05; I2 = 75.81), high-density lipoprotein cholesterol (HDL-C) level (r = 0.11; 95% CI, 0.05-0.18; I2 = 69.06), total cholesterol to HDL-C ratio (r = -0.19; 95% CI, -0.26 to -0.13; I2 = 67.07), triglyceride levels (r = -0.10; 95% CI, -0.18 to -0.02; I2 = 73.43), homeostasis model assessment for insulin resistance (r = -0.12; 95% CI, -0.18 to -0.06; I2 = 68.26), fasting insulin level (r = -0.07; 95% CI, -0.11 to -0.03; I2 = 0), and cardiometabolic risk (r = -0.18; 95% CI, -0.29 to -0.07; I2 = 90.61) at follow-up. Meta-regression analyses found that early associations in waist circumference (β = 0.014; 95% CI, 0.002-0.026), skinfold thickness (β = 0.006; 95% CI, 0.002-0.011), HDL-C level (β = -0.006; 95% CI, -0.011 to -0.001), triglyceride levels (β = 0.009; 95% CI, 0.004-0.014), and cardiometabolic risk (β = 0.007; 95% CI, 0.003-0.011) from baseline to follow-up dissipated over time. Weak-moderate associations were found between change in CRF and body mass index (r = -0.17; 95% CI, -0.24 to -0.11; I2 = 39.65), skinfold thickness (r = -0.36; 95% CI, -0.58 to -0.09; I2 = 96.84), obesity (r = -0.21; 95% CI, -0.35 to -0.06; I2 = 91.08), HDL-C level (r = 0.05; 95% CI, 0.02-0.08; I2 = 0), low-density lipoprotein cholesterol level (r = -0.06; 95% CI, -0.11 to -0.01; I2 = 58.94), and cardiometabolic risk (r = -0.08; 95% CI, -0.15 to -0.02; I2 = 69.53) later in life.

CONCLUSIONS AND RELEVANCE

This study suggests that early intervention and prevention strategies that target youth CRF may be associated with maintaining health parameters in later life.

Elements of Effective Population Surveillance Systems for Monitoring Obesity in School Aged Children

The continuing high prevalence of child overweight and obesity globally means that it remains the most common chronic health condition in children. Population-based child obesity surveillance systems are critical for monitoring trends in obesity and related behaviours, and determining the overall effect of child obesity prevention strategies. Effective surveillance systems may vary in methods, scope, purpose, objectives, and attributes, and our aim was to provide an overview of child obesity surveillance systems globally, and to highlight main components and other types of survey data that can enhance our understanding of child obesity. Measures of adiposity, including body mass index and waist circumference are essential, but effective surveillance must also include measures of weight-related behaviours, including diet, physical activity, sedentary time, and sleep. While objective measures are desirable, the variability in psychometrics and rapid evolution of wearable devices is potentially problematic for examining long-term trends over time and how behaviours may change. Questionnaires on self-reported behaviours are often used but also have limitations. Because the determinants of obesity are not only functioning at the individual level, some measures of the broader environmental and commercial determinants, including the built and food environments, are useful to guide upstream policy decisions.

Representative Percentile Curves of Physical Fitness From Early Childhood to Early Adulthood: The MoMo Study

Introduction: Monitoring of physical fitness in youth is important because physical fitness is a summative indicator of health. From a developmental and preventive perspective, physical fitness levels are relatively stable from childhood to early adulthood. Thus, it is important to monitor physical fitness on a population based level being able to intervene at early stages (1). In order to reliably assess and evaluate the physical fitness of youth, a reliable system of standard values based on representative data is required. The aim of this analysis is to report sex- and age-specific physical fitness percentile curves from childhood to early adulthood in a nationwide sample in Germany. Methods: We use data from the nationwide representative Motorik Modul (MoMo) Study in Germany (data collection wave 1: 2009-2012; age: 4-23 years; n = 3,742; 50.1% female). Physical fitness was assessed by means of the MoMo test profile covering four dimensions of physical fitness (strength, endurance, coordination, and flexibility) and including eight physical fitness items. Percentile curves were fitted using the LMS transformation method of Cole and Green. Results: Standardized age- and sex-specific physical fitness percentiles were calculated for eight items: ergometric endurance testing, standing long jump, push-ups, sit-ups, jumping side-ways, balancing backwards, static stand, and stand and reach test. The physical fitness curves differ according to gender and the fitness dimension. Physical fitness improvements with age are linear (e.g., max. strength) or curvilinear (e.g., coordination) and have their stagnation points at different times over the course of adolescence. Discussion: Our results provide for the first time sex- and age-specific physical fitness percentile curves for Germany from 4 to 17 years. Differences in curve-shapes indicating a timed and capacity-specific physical fitness development. Nationwide German physical fitness percentiles can be useful in comparing different populations (e.g., cross-country), reporting secular trends, comparing special groups, and to evaluate physical fitness interventions.

The reciprocal relationship between body mass index categories and physical fitness: A 4-year prospective cohort study of 20 000 Chinese children

INTRODUCTION

Body mass index (BMI) categories and physical fitness are associated but the reciprocal relationship between BMI categories and physical fitness has not been investigated. This study aims to investigate the longitudinal reciprocal relationship between BMI categories and physical fitness.

METHODS

This is a population-based 4-year cohort study in 48 elementary schools. Children aged 6 to 9 years at recruitment were included. BMI categories and physical fitness including handgrip strength, core muscle endurance, flexibility, and cardiorespiratory fitness were measured using standard equipment and protocol.

RESULTS

Among 26 392 eligible participants, 19 504 (73.9%) were successfully followed for 3 years. Baseline obesity prevalence was 5.9%. After 3 years, those who were unfit at baseline had an increased risk of obesity (risk ratio [RR] 1.41, 95% CI 1.16-1.71, P < .001) and those who were fit at baseline had a decreased risk of obesity (RR 0.69, 95% CI 0.60-0.80, P < .001) compared with moderately fit children. Furthermore, improvement of fitness predicted decreased risk of obesity. Similarly, normal body weight also predicted better physical fitness. The path analysis confirmed a strong reciprocal relationship between physical fitness and obesity.

CONCLUSIONS

Better physical fitness was prospectively associated with normal weight and vice versa. Physically fit children were more likely to maintain a healthy weight and those with a healthy weight were more likely to be physically fit, which is important for healthy development.

Secular Trends in Physical Fitness of Children and Adolescents: A Review of Large-Scale Epidemiological Studies Published after 2006

Physical fitness (PF) of children and adolescents is an important resource for their future health. Population-based studies, however, rarely report secular changes of PF, although monitoring of these is crucial to deriving information for adequate interventions. This review aims to report trends in PF of children and adolescents. A literature search was conducted in PubMed in July 2019. Cohort studies published in English allowing statements to be made on trends in PF by comparing youth between the ages of four and 18 years were included. The review identified 24 studies from 16 countries meeting the inclusion criteria, with an overall sample size of more than 860,000 children and adolescents. Through a standardized quality assessment tool, we classified two studies as strong, 21 as moderate, and only one as weak. We analyzed specific secular trends separately for the five different dimensions: endurance, strength, speed, flexibility, and coordination. The majority of studies report a decline of PF over time; however, a few studies report conflicting results. Performance in endurance, strength, and flexibility decreased over time, whereas there was no consistent trend reported for speed and coordination. Overall, there is no international standard on examining and reporting changes or secular trends in PF of children and adolescents, and comparability of studies is limited due to heterogeneous conditions of conducting and analyzing PF tests. Consequently, standardized and consistent international monitoring should be implemented.

Changes in cardiorespiratory fitness through adolescence predict metabolic syndrome in young adults

BACKGROUND AND AIMS

Higher cardiorespiratory fitness (CRF) has been suggested to reduce the risk of metabolic syndrome (MetS). We aimed to longitudinally examine the changes of CRF on MetS and its risk factors from adolescence to adulthood.

METHODS AND RESULTS

At the age of 15 years, 1076 subjects were recruited from 2 cohorts. CRF was measured on a cycle ergometer. MetS was classified as having at least 3 of the following parameters above the threshold of risk factors: waist circumference, triglycerides, high-density lipoprotein cholesterol (HDL), high blood pressure (BP) and fasting glucose. In addition, insulin, total cholesterol and low-density lipoprotein cholesterol were measured and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Persistently high, increasing, decreasing and persistently low CRF groups were formed according to change in CRF from adolescence to adulthood. Longitudinal increase in CRF was positively associated with change in HDL and negatively associated with change in insulin, HOMA-IR, triglycerides, BP and prevalence of MetS after adjustment for potential confounders. Subjects with persistently low CRF had 11.5- to 34.4-times higher risk of MetS at the age of 25 and 33 years compared to subjects with persistently high CRF and 14.6- to 15.9-times higher risk compared to the increasing CRF group.

CONCLUSION

Higher CRF is strongly related to lower values of MetS risk factors. Increasing CRF from adolescence to adulthood reduces the risk to have MetS later in adulthood. High CRF in adolescence that decreases during adulthood has similar risks to MetS compared to individuals with persistently low CRF.

Physical Fitness and Self-Rated Health in Children and Adolescents: Cross-Sectional and Longitudinal Study

Self-rated health (SRH) is an independent determinant for all-cause mortality. We aimed to examine the independent and combined associations of components of physical fitness with SRH at baseline (cross-sectional) and two years later (longitudinal) in children and adolescents. Spanish youth (N = 1378) aged 8 to 17.9 years participated at baseline. The dropout rate at 2-year follow-up was 19.5% (n = 270). Participants were categorized as either children (8 to 11.9 years age) or adolescents (12 to 17.9 years age). The ALPHA health- related fitness test battery for youth was used to assess physical fitness, and SRH was measured by a single-item question. Cumulative link, ANOVA and ANCOVA models were fitted to analyze the data. Cardiorespiratory fitness, relative upper body isometric muscular strength, muscular strength score, and global physical fitness were positively associated with SRH in children (OR, 1.048; 95% CI, 1.020–1.076; OR, 18.921; 95% CI, 3.47–104.355; OR, 1.213; 95% CI, 1.117–1.319, and OR, 1.170; 95% CI, 1.081–1.266, respectively; all p < 0.001) and adolescents (OR, 1.057; 95% CI, 1.037–1.076; OR, 5.707; 95% CI, 1.122–29.205; OR, 1.169; 95% CI, 1.070–1.278, and OR, 1.154 95% CI, 1.100–1.210, respectively; all p < 0.001); and motor fitness was positively associated with SRH only in adolescents at baseline (OR, 1.192; 95% CI, 1.066–1.309; p < 0.01). Cardiorespiratory fitness and global physical fitness were positively associated with SRH in children two years later (OR, 1.056; 95% CI, 1.023–1.091; p < 0.001; and OR, 1.082; 95% CI, 1.031–1.136; p < 0.01; respectively). Only cardiorespiratory fitness was independently associated with SRH in children and adolescents at baseline (OR, 1.059; 95% CI, 1.029–1.090; and OR, 1.073; 95% CI, 1.050–1.097, respectively; both p < 0.001) and two years later (OR, 1.075; 95% CI, 1.040–1.112; p < 0.001; and OR, 1.043; 95% CI, 1.014–1.074; p < 0.01, respectively). A high level of cardiorespiratory fitness at baseline or maintaining high levels of cardiorespiratory fitness from the baseline to 2-year follow-up were associated with a higher level of SRH at 2-year follow-up in children (p < 0.01) and adolescents (p < 0.05). These findings emphasize the importance of cardiorespiratory fitness as strong predictor of present and future SRH in youth. Intervention programs to enhance cardiorespiratory fitness level of the youth population are urgently needed for present and future youth’s health.

Non-HDL Cholesterol Levels in Childhood and Carotid Intima-Media Thickness in Adulthood

BACKGROUND

Elevated non-high-density lipoprotein cholesterol (HDL-C) levels are used to identify children at increased cardiovascular risk, but the use of non-HDL-C in childhood to predict atherosclerosis is unclear. We examined whether the National Heart, Lung, and Blood Institute classification of youth non-HDL-C status predicts high common carotid artery intima-media thickness in adulthood.

METHODS

We analyzed data from 4 prospective cohorts among 4582 children aged 3 to 19 years who were remeasured as adults (mean follow-up of 26 years). Non-HDL-C status in youth and adulthood was classified according to cut points of the National Heart, Lung, and Blood Institute and the National Cholesterol Education Program Adult Treatment Panel III. High carotid intima-media thickness (cIMT) in adulthood was defined as at or above the study visit-, age-, sex-, race-, and cohort-specific 90th percentile of intima-media thickness.

RESULTS

In a log-binomial regression analysis adjusted with age at baseline, sex, cohort, length of follow-up, baseline BMI, and systolic blood pressure, children with dyslipidemic non-HDL-C were at increased risk of high cIMT in adulthood (relative risk [RR], 1.29; 95% confidence interval [CI], 1.07-1.55). Compared with the persistent normal group, the persistent dyslipidemia group (RR, 1.80; 95% CI, 1.37-2.37) and incident dyslipidemia (normal to dyslipidemia) groups (RR, 1.45; 95% CI, 1.07-1.96) had increased risk of high cIMT in adulthood, but the risk was attenuated for the resolution (dyslipidemia to normal) group (RR, 1.17; 95% CI, 0.97-1.41).

CONCLUSIONS

Dyslipidemic non-HDL-C levels predict youth at risk for developing high cIMT in adulthood. Those who resolve their non-HDL-C dyslipidemia by adulthood have normalized risk of developing high cIMT in adulthood.

Developmental pathways of cardiorespiratory fitness from 6 to 15 years of age

Most of the information gathered about physical fitness of paediatric populations are cross-sectional, resulting in normative perspectives that account for average values relative to age, but not to a comprehensive understanding of developmental individual trajectories. The aim of this study was to model the longitudinal development of cardiorespiratory fitness of boys and girls from 6 to 15 years of age, using an individual centred approach. Two hundred twenty-nine school children (128 boys; 101 girls) were followed on their 20 metres shuttle run test (20mSRT) results from 6 to 15 years of age. Annual measurements were made during the four years of primary school, and again at grade 9th or 10th. Individual trajectories of 20mSRT development were modelled and grouped according to their similarities of change in three different developmental pathways that were included in subsequent hierarchical nested models for testing each sex developmental model of cardiorespiratory fitness. Final models including the developmental pathways showed better deviance statistics (p < .001). Interindividual slope variances were almost zero, and statistically non-significant (0.05 boys 0.01 girls; p > .50), meaning these models capture well the existing variability, in respect to the rate of change. Individual pathways of change in the performance of 20mSRT test can be detected in childhood and adolescence. Additionally, all individual's developmental trajectories in 20mSRT can be described using three significantly different slopes. These pathways are indicative of a high, average, or low rate of change in performance over the years and differ from the normative approach.

Effects of physical activity and smoking on cardio-ankle vascular index, respiratory muscle strength, and exercise performance in early normal weight adulthood: a cross-sectional study

Few studies have shown the impact of unhealthy habits on arterial stiffness, respiratory muscle strength and exercise performance in early normal weight adulthood. This study sought to determine the effects of physical activity and smoking on its parameters in normal weight male participants. Forty-eight participants were divided into four groups: physically inactive nonsmokers and smokers and physically active nonsmokers and smokers (n=12 in each group). All of the participants were measured for body composition, arterial stiffness, respiratory muscle strength and exercise performance. Two-way analysis of variance design was used to test the main and interaction effects of physical activity by group (smokers vs. nonsmokers). P-value of less than 0.05 was considered as a statistically significant difference. As a result, cardio-ankle vascular index and respiratory muscle strength were diminished in smokers and physically inactive participants, while body and visceral fat mass were increased in both those groups. Fat-free mass was lower in only physically inactive participants. This study also found the interaction effects on body fat and arterial stiffness. In conclusion, participants with healthy normal weight, but smoked and performed inappropriate physical activity, exhibited body composition imbalance, decreased respiratory muscle strength, exercise performance, and increased arterial stiffness. Therefore, smoking cessation and exercise in younger adults are appropriate ways of improving body composition, respiratory muscle strength, aerobic capacity and arterial stiffness instead of trying to control their weight by smoking.

Effects of school-based physical activity and multi-micronutrient supplementation intervention on growth, health and well-being of schoolchildren in three African countries: the KaziAfya cluster randomised controlled trial protocol with a 2 × 2 factorial design

BACKGROUND

In low- and middle-income countries, infectious diseases remain a key public health issue. Additionally, non-communicable diseases are a rapidly growing public health problem that impose a considerable burden on population health. One way to address this dual disease burden, is to incorporate (lifestyle) health promotion measures within the education sector. In the planned study, we will (i) assess and compare physical activity, physical fitness, micronutrient status, body composition, infections with soil-transmitted helminths, Schistosoma mansoni, malaria, inflammatory and cardiovascular health risk markers, cognitive function, health-related quality of life, and sleep in schoolchildren in Côte d'Ivoire, South Africa and Tanzania. We will (ii) determine the bi- and multivariate associations between these variables and (iii) examine the effects of a school-based health intervention that consists of physical activity, multi-micronutrient supplementation, or both.

METHODS

Assuming that no interaction occurs between the two interventions (physical activity and multi-micronutrient supplementation), the study is designed as a cluster-randomised, placebo-controlled trial with a 2 × 2 factorial design. Data will be obtained at three time points: at baseline and at 9 months and 21 months after the baseline assessment. In each country, 1320 primary schoolchildren from grades 1-4 will be recruited. In each school, classes will be randomly assigned to one of four interventions: (i) physical activity; (ii) multi-micronutrient supplementation; (iii) physical activity plus multi-micronutrient supplementation; and (iv) no intervention, which will serve as the control. A placebo product will be given to all children who do not receive multi-micronutrient supplementation. After obtaining written informed consent from the parents/guardians, the children will be subjected to anthropometric, clinical, parasitological and physiological assessments. Additionally, fitness tests will be performed, and children will be invited to wear an accelerometer device for 7 days to objectively assess their physical activity. Children infected with S. mansoni and soil-transmitted helminths will receive deworming drugs according to national policies. Health and nutrition education will be provided to the whole study population independently of the study arm allocation.

DISCUSSION

The study builds on the experience and lessons of a previous study conducted in South Africa. It involves three African countries with different social-ecological contexts to investigate whether results are generalisable across the continent.

TRIAL REGISTRATION

The study was registered on August 9, 2018, with ISRCTN. https://doi.org/10.1186/ISRCTN29534081.

Effects of school-based physical activity and multi-micronutrient supplementation intervention on growth, health and well-being of schoolchildren in three African countries: the KaziAfya cluster randomised controlled trial protocol with a 2 × 2 factorial design

BACKGROUND

In low- and middle-income countries, infectious diseases remain a key public health issue. Additionally, non-communicable diseases are a rapidly growing public health problem that impose a considerable burden on population health. One way to address this dual disease burden, is to incorporate (lifestyle) health promotion measures within the education sector. In the planned study, we will (i) assess and compare physical activity, physical fitness, micronutrient status, body composition, infections with soil-transmitted helminths, Schistosoma mansoni, malaria, inflammatory and cardiovascular health risk markers, cognitive function, health-related quality of life, and sleep in schoolchildren in Côte d'Ivoire, South Africa and Tanzania. We will (ii) determine the bi- and multivariate associations between these variables and (iii) examine the effects of a school-based health intervention that consists of physical activity, multi-micronutrient supplementation, or both.

METHODS

Assuming that no interaction occurs between the two interventions (physical activity and multi-micronutrient supplementation), the study is designed as a cluster-randomised, placebo-controlled trial with a 2 × 2 factorial design. Data will be obtained at three time points: at baseline and at 9 months and 21 months after the baseline assessment. In each country, 1320 primary schoolchildren from grades 1-4 will be recruited. In each school, classes will be randomly assigned to one of four interventions: (i) physical activity; (ii) multi-micronutrient supplementation; (iii) physical activity plus multi-micronutrient supplementation; and (iv) no intervention, which will serve as the control. A placebo product will be given to all children who do not receive multi-micronutrient supplementation. After obtaining written informed consent from the parents/guardians, the children will be subjected to anthropometric, clinical, parasitological and physiological assessments. Additionally, fitness tests will be performed, and children will be invited to wear an accelerometer device for 7 days to objectively assess their physical activity. Children infected with S. mansoni and soil-transmitted helminths will receive deworming drugs according to national policies. Health and nutrition education will be provided to the whole study population independently of the study arm allocation.

DISCUSSION

The study builds on the experience and lessons of a previous study conducted in South Africa. It involves three African countries with different social-ecological contexts to investigate whether results are generalisable across the continent.

TRIAL REGISTRATION

The study was registered on August 9, 2018, with ISRCTN. https://doi.org/10.1186/ISRCTN29534081.

Utility of Different Blood Pressure Measurement Components in Childhood to Predict Adult Carotid Intima-Media Thickness

Childhood blood pressure (BP) levels predict adult subclinical atherosclerosis. However, the best childhood BP component for prediction has not been determined. This study comprised 5925 participants aged 3 to 18 years from 6 cohorts who were followed into adulthood (mean follow-up 25.8±6.2 years). Childhood BP was measured by using a standard mercury sphygmomanometer in all cohorts. Study-specific carotid intima-media thickness ≥90th percentile was used to define subclinical atherosclerosis. Per SD change in the predictor, childhood systolic BP (SBP; age- and sex-adjusted odds ratio [95% CI], 1.24 [1.13-1.37]), mean arterial pressure (1.10 [1.07-1.13]), and pulse pressure (1.15 [1.05-1.27]) were associated with increased adulthood intima-media thickness. In age- and sex-adjusted analyses, area under the receiver operating characteristic curves for SBP ( C value [95% CI], 0.677 [0.657-0.704]) showed significantly improved prediction compared with diastolic BP (0.669 [0.646-0.693], P=0.006) or mean arterial pressure (0.674 [0.653-0.699], P=0.01). Pulse pressure provided a C value that was not different from SBP (0.676 [0.653-0.699], P=0.16). Combining different BP components did not improve prediction over SBP measurement alone. Based on the associations with adult carotid intima-media thickness, cut points for elevated SBP were 105 mm Hg for 3- to 6-year-old boys, 108 mm Hg for 3- to 6-year-old girls, 108 mm Hg for 7- to 12-year-old boys, 106 mm Hg for 7- to 12-year-old girls, 123 mm Hg for 13- to 18-year-old boys, and 115 mm Hg for 13- to 18-year-old girls. Our analyses suggest that several childhood BP measurement components are related to adulthood carotid intima-media thickness. Of these, SBP provided the best predictive ability.

Life on holidays: differences in activity composition between school and holiday periods in Australian children

BACKGROUND

Recently, a small number of studies have suggested that gains in fitness and reductions in body fat achieved during the school term are reversed or stagnate during the holiday period. This may be associated with changed activity patterns. The aim of this study was to compare 24-h activity compositions between school and holiday periods in Australian children.

METHODS

The participants in this study were 366 children (53% female, 13.4 ± 2.3 years) who were a subgroup of the 2007 Australian National Children's Nutrition and Physical Activity Survey. Each child recalled use of time on at least one school day, one weekend day and one holiday using the Multimedia Activity Recall for Children and Adults. Composite "in-term" and "holiday" use-of-time profiles were generated by weighting school days by 5, and weekends by 2 where data were available. Difference between holiday and in-term time use was assessed using a compositional multivariate linear model for repeated measures. Subsequent models tested for interaction between time of measurement and socio-economic status or body mass index.

RESULTS

Time use was significantly different between holidays and in-term days (F = 103, p < 0.0001). On holidays, children accumulated 140 min less School-related time, compensated by sleeping 40 min longer, 58 min more Screen Time, and 35 min more Domestic/Social time. Children spent 10 min less in vigorous physical activity, and although sitting time was 33 min/day less during holidays, estimated total daily energy expenditure (TDEE) was 5.4% lower. Differences between holiday and in-term activity compositions did not vary by parental education (F = 1.2, p = 0.25), postcode-level socio-economic status (F = 0.9, p = 0.56) or weight status (F = 1.7, p = 0.07).

CONCLUSIONS

In this subsample of a nationally representative survey of Australian children, holidays were characterised by longer sleep and higher TV and videogame time, lower vigorous activity and lower TDEE. Uncompensated by dietary adjustments, these differences would result in an accumulation of about 650 g of fat over a six-week holiday period. Holiday activity patterns may be a promising focus for obesity prevention efforts.

Physical fitness is predictive for 5-year survival in older adults with intellectual disabilities

BACKGROUND

The very low physical fitness levels of people with intellectual disabilities (ID) may influence their life expectancy. Therefore, we investigated the predictive value of physical fitness for survival in older adults with intellectual disabilities.

METHOD

In the Healthy Ageing and Intellectual Disabilities (HA-ID) study,the physical fitness levels of 900 older adults (≥50 years; 61.5 ± 8.1 years) were measured at baseline. All-cause mortality was collected over a 5-year follow-up period. Cox proportional hazard models were used to determine the association between each physical fitness test and survival, adjusted for age, sex, level of ID, and Down syndrome.

RESULTS

The physical fitness components that were independently predictive for survival were manual dexterity (HR = 0.96 [0.94-0.98]), visual reaction time (HR = 1.57 [1.28-1.94]), balance (HR = 0.97 [0.95-0.99]), comfortable gait speed (HR = 0.65 [0.54-0.78]), fast gait speed (HR = 0.81 [0.72-0.91]), grip strength (HR = 0.97 [0.94-0.99]) and cardiorespiratory fitness (HR = 0.997 [0.995-0.999]), with a better physical fitness showing a lower mortality risk.

CONCLUSION

We showed for the first time that physical fitness was independently associated with survival in older adults with intellectual disabilities. Improving and maintaining physical fitness must become an essential part of care and support for this population.

Cardiorespiratory Fitness in Childhood and Adolescence Affects Future Cardiovascular Risk Factors: A Systematic Review of Longitudinal Studies

BACKGROUND

Although cardiorespiratory fitness (CRF) in childhood and adolescence may be linked to future cardiovascular health, there is currently limited evidence for a longitudinal association.

OBJECTIVES

To provide a systematic review on the prospective association between CRF in childhood and adolescence and cardiovascular disease (CVD) risk factors at least 2 years later.

METHODS

Using a systematic search of Medline, Embase, and SPORTDiscus, relevant articles were identified by the following criteria: generally healthy children and adolescents between 3 and 18 years of age with CRF assessed at baseline, and a follow-up period of ≥ 2 years. The outcome measures were CVD risk factors. We appraised quality of the included articles with STROBE and QUIPS checklists.

RESULTS

After screening 7524 titles and abstracts, we included 38 articles, assessing 44,169 children and adolescents followed up for a median of 6 years. Eleven articles were of high quality. There was considerable heterogeneity in methodology, measurement of CRF, and outcomes, which hampered meta-analysis. In approximately half of the included articles higher CRF in childhood and adolescence was associated with lower body mass index (BMI), waist circumference, body fatness and lower prevalence of metabolic syndrome in later life. No associations between CRF in childhood and adolescence and future waist-to-hip ratio, blood pressure, lipid profile, and glucose homeostasis were observed.

CONCLUSION

Although about half of the included articles reported inverse associations between CRF in childhood and adolescence and future BMI, body fatness, and metabolic syndrome, evidence for other CVD risk factors was unconvincing. Many articles did not account for important confounding factors such as adiposity. Recommendations for future research include standardizing the measurement of CRF, i.e. by reporting VO_2max, using standardized outcome assessments, and performing individual patient data meta-analyses.

Aerobic Capacity Is Related to Multiple Other Aspects of Physical Fitness: A Study in a Large Sample of Lithuanian Schoolchildren

This study evaluated how aerobic capacity is related to performance in other aspects of health-related physical fitness among schoolchildren. The study involved >15,200 schoolchildren of both genders aged 11–18 years, who were tested with a reliable tests from Eurofit battery for most important aspects of exercise capacity and anthropometrics from 1992 to 2012. The analysis showed that aerobic capacity was weakly but significantly positively related to all other aspects of exercise abilities tested in all age groups for both genders. Variance of performance in agility shuttle run and standing broad jump were each explained by aerobic capacity the strongest (>10%), followed by weaker but still significant positive relation of aerobic capacity with the abilities in bent arm hang and abdominal curl tests (aerobic capacity explaining ∼6.5% of the variance of the performance in these tests), as well as in balance and flexibility tasks (aerobic capacity significantly explaining ∼3% of the variance). Thus, while aerobic capacity in schoolchildren of all ages and both genders can explain the performance in other aspects of physical fitness and especially leg muscle power, the percent of explained variance in the results of any these tests was not high and therefore aerobic capacity should be tested as a separate important fitness parameter which cannot be substituted by other tests from the Eurofit battery.

Predictive utility of childhood anthropometric measures on adult glucose homeostasis measures: a 20-year cohort study

BACKGROUND/OBJECTIVES

Childhood body mass index (BMI) predicts adult glucose homeostasis measures and type 2 diabetes mellitus, but little is known about the predictive utility of other anthropometric measures in childhood. We aimed to identify the anthropometric measure in childhood that best predicts adult glucose homeostasis measures and examine if the combination of additional anthropometric measures further improves predictive utility.

METHODS

A 20-year follow-up of children participating in the Childhood Determinants of Adult Health Study (n = 2345, aged 7-15 years at baseline). Baseline anthropometric measures were waist circumference (WC), WC adjusted for height, weight adjusted for height, hip circumference, waist-hip-ratio, waist-height-ratio, BMI, conicity index, abdominal volume index (AVI), body adiposity index, and a body shape index. Fasting glucose and insulin levels measured at follow-up were used to define insulin resistance (HOMA2-IR), low beta-cell function (HOMA2-β), high fasting insulin, and impaired fasting glucose (IFG).

RESULTS

All child anthropometric measures were significantly associated with HOMA2-IR, HOMA2-β, and high fasting insulin (relative risk = 1.12-1.55), but not IFG. AVI had the largest area under receiver-operating curve (AUC) in predicting adult HOMA2-IR (AUC, 95% confidence interval: 0.610, 0.584-0.637), HOMA2-β (0.615, 0.588-0.642) and high fasting insulin (0.613, 0.587-0.639). Combining each additional anthropometric measure with AVI did not appreciably increase predictive utility (an increase of 0.001-0.002 in AUC, p > 0.05 for all).

CONCLUSIONS

Anthropometric measures from a single time-point in childhood are associated with insulin-related outcomes 20-year later in adulthood. However, overall predictive utility was low and was not substantially enhanced by combining multiple different child anthropometric measures.

Childhood cardiorespiratory fitness, muscular fitness and adult measures of glucose homeostasis

OBJECTIVES

To assess whether childhood cardiorespiratory fitness (CRF) and muscular fitness phenotypes (strength, power, endurance) predict adult glucose homeostasis measures.

DESIGN

Prospective longitudinal study.

METHODS

Study examining participants who had physical fitness measured in childhood (aged 7-15 years) and who attended follow-up clinics approximately 20 years later and provided a fasting blood sample which was tested for glucose and insulin. Physical fitness measurements included muscular strength (right and left grip, shoulder flexion, shoulder and leg extension), power (standing long jump distance) and endurance (number of push-ups in 30s), and CRF (1.6km run duration). In adulthood, fasting glucose and insulin levels were used to derive glucose homeostasis measures of insulin resistance (HOMA2-IR) and beta cell function (HOMA2-β).

RESULTS

A standard deviation increase in childhood CRF or muscular strength (males) was associated with fasting glucose (CRF: β=-0.06mmol/L), fasting insulin (CRF: β=-0.73mU/L; strength: β=-0.40mU/L), HOMA2-IR (CRF: β=-0.06; strength: β=-0.05) and HOMA2-β (CRF: β=-3.06%; strength: β=-2.62%) in adulthood, independent of the alternative fitness phenotype (all p<0.01). Adjustment for childhood waist circumference reduced the effect by 17-35% for CRF and 0-15% for muscular strength (males) and statistical significance remained for all associations expect between CRF, fasting glucose and HOMA2-β (p>0.06).

CONCLUSIONS

CRF and muscular fitness in childhood were inversely associated with measures of fasting insulin, insulin resistance and beta cell function in adulthood. Childhood CRF and muscular fitness could both be potential independent targets for strategies to help reduce the development of adverse glucose homeostasis.

A Randomized Controlled Trial to Prevent Depression and Ameliorate Insulin Resistance in Adolescent Girls at Risk for Type 2 Diabetes

BACKGROUND

Prospective data suggest depressive symptoms worsen insulin resistance and accelerate type 2 diabetes (T2D) onset.

PURPOSE

We sought to determine whether reducing depressive symptoms in overweight/obese adolescents at risk for T2D would increase insulin sensitivity and mitigate T2D risk.

METHOD

We conducted a parallel-group, randomized controlled trial comparing a 6-week cognitive-behavioral (CB) depression prevention group with a 6-week health education (HE) control group in 119 overweight/obese adolescent girls with mild-to-moderate depressive symptoms (Center for Epidemiological Studies-Depression Scale [CES-D] ≥16) and T2D family history. Primary outcomes were baseline to post-intervention changes in CES-D and whole body insulin sensitivity index (WBISI), derived from 2-h oral glucose tolerance tests. Outcome changes were compared between groups using ANCOVA, adjusting for respective baseline outcome, puberty, race, facilitator, T2D family history degree, baseline age, adiposity, and adiposity change. Multiple imputation was used for missing data.

RESULTS

Depressive symptoms decreased (p < 0.001) in CB and HE from baseline to posttreatment, but did not differ between groups (ΔCESD = -12 vs. -11, 95 % CI difference = -4 to +1, p = 0.31). Insulin sensitivity was stable (p > 0.29) in CB and HE (ΔWBISI = 0.1 vs. 0.2, 95 % CI difference = -0.6 to +0.4, p = 0.63). Among all participants, reductions in depressive symptoms were associated with improvements in insulin sensitivity (p = 0.02).

CONCLUSIONS

Girls at risk for T2D displayed reduced depressive symptoms following 6 weeks of CB or HE. Decreases in depressive symptoms related to improvements in insulin sensitivity. Longer-term follow-up is needed to determine whether either program causes sustained decreases in depressive symptoms and improvements in insulin sensitivity.

TRIAL REGISTRATION NUMBER

The trial was registered with clinicaltrials.gov (NCT01425905).

Cardiorespiratory Fitness Cutoff Points for Early Detection of Present and Future Cardiovascular Risk in Children: A 2-Year Follow-up Study

OBJECTIVE

To examine the association between cardiorespiratory fitness (CRF) at baseline and cardiovascular disease (CVD) risk in 6- to 10-year-olds (cross-sectional) and 2 years later (8- to 12-year-olds [longitudinal]) and whether changes with age in CRF are associated with CVD risk in children aged 8 to 12 years.

PATIENTS AND METHODS

Spanish primary schoolchildren (n=236) aged 6 to 10 years participated at baseline. Of the 23 participating primary schools, 22% (n=5) were private schools and 78% (n=18) were public schools. The dropout rate at 2-year follow-up was 9.7% (n=23). The 20-m shuttle run test was used to estimate CRF. The CVD risk score was computed as the mean of 5 CVD risk factor standardized scores: sum of 2 skinfolds, systolic blood pressure, insulin/glucose, triglycerides, and total cholesterol/high-density lipoprotein cholesterol.

RESULTS

At baseline, CRF was inversely associated with single CVD risk factors (all P<.05) and CVD risk score at baseline and follow-up (P<.001). Cardiorespiratory fitness cutoff points of 39.0 mL/kg per minute or greater in boys and 37.5 mL/kg per minute or greater in girls are discriminative to identify CVD risk in childhood (area under the curve, >0.85; P<.001) and to predict CVD risk 2 years later (P=.004). Persistent low CRF or the decline of CRF from 6-10 to 8-12 years of age is associated with increased CVD risk at age 8 to 12 years (P<.001).

CONCLUSION

During childhood, CRF is a strong predictor of CVD risk and should be monitored to identify children with potential CVD risk.

Impact of Lipid Measurements in Youth in Addition to Conventional Clinic-Based Risk Factors on Predicting Preclinical Atherosclerosis in Adulthood: International Childhood Cardiovascular Cohort Consortium

BACKGROUND

Data suggest that the prediction of adult cardiovascular disease using a model comprised entirely of adult nonlaboratory-based risk factors is equivalent to an approach that additionally incorporates adult lipid measures. We assessed and compared the utility of a risk model based solely on nonlaboratory risk factors in adolescence versus a lipid model based on nonlaboratory risk factors plus lipids for predicting high-risk carotid intima-media thickness (cIMT) in adulthood.

METHODS

The study comprised 2893 participants 12 to 18 years of age from 4 longitudinal cohort studies from the United States (Bogalusa Heart Study and the Insulin Study), Australia (Childhood Determinants of Adult Health Study), and Finland (The Cardiovascular Risk in Young Finns Study) and followed into adulthood when cIMT was measured (mean follow-up, 23.4 years). Overweight status was defined according to the Cole classification. Hypertension was defined according to the Fourth Report on High Blood Pressure in Children and Adolescents from the National High Blood Pressure Education Program. High-risk plasma lipid levels were defined according to the National Cholesterol Education Program Expert Panel on Cholesterol Levels in Children. High cIMT was defined as a study-specific value ≥90th percentile. Age and sex were included in each model.

RESULTS

In univariate models, all risk factors except for borderline high and high triglycerides in adolescence were associated with high cIMT in adulthood. In multivariable models (relative risk [95% confidence interval]), male sex (2.7 [2.0-2.6]), prehypertension (1.4 [1.0-1.9]), hypertension (1.9 [1.3-2.9]), overweight (2.0 [1.4-2.9]), obesity (3.7 [2.0-7.0]), borderline high low-density lipoprotein cholesterol (1.6 [1.2-2.2]), high low-density lipoprotein cholesterol (1.6 [1.1-2.1]), and borderline low high-density lipoprotein cholesterol (1.4 [1.0-1.8]) remained significant predictors of high cIMT (P<0.05). The addition of lipids into the nonlaboratory risk model slightly but significantly improved discrimination in predicting high cIMT compared with nonlaboratory-based risk factors only (C statistics for laboratory-based model 0.717 [95% confidence interval, 0.685-0.748] and for nonlaboratory 0.698 [95% confidence interval, 0.667-0.731]; P=0.02).

CONCLUSIONS

Nonlaboratory-based risk factors and lipids measured in adolescence independently predicted preclinical atherosclerosis in young adulthood. The addition of lipid measurements to traditional clinic-based risk factor assessment provided a statistically significant but clinically modest improvement on adolescent prediction of high cIMT in adulthood.

Childhood Muscular Fitness Phenotypes and Adult Metabolic Syndrome

PURPOSE

The objective of this study is to determine whether childhood muscular fitness phenotypes (strength, endurance, and power) are independently associated with adult metabolic syndrome (MetS).

METHODS

We conducted a longitudinal study including 737 participants who had muscular fitness measures in 1985 when age 9, 12, or 15 yr and attended follow-up in young adulthood 20 yr later when measures of MetS were collected. Childhood measures of muscular fitness included strength (right and left grip, leg, and shoulder extension and flexion), endurance (number of push-ups in 30 s), and power (distance of a standing long jump). A muscular fitness score was created using all individual muscular fitness phenotypes. In adulthood, waist circumference, blood pressure, HDL cholesterol, triglycerides, and glucose were measured. Adult outcomes were MetS defined using the harmonized definition and a continuous MetS risk score.

RESULTS

Participants with childhood muscular strength, muscular power, and combined muscular fitness score in the highest third had significantly lower relative risk (RR) for MetS and a lower continuous MetS score in adulthood independent of cardiorespiratory fitness than those in the lowest third (strength: RR = 0.21 (0.09, 0.49) β = -0.46 (-0.59, -0.34) power: RR = 0.26 (0.12, 0.60), β = -0.36 (-0.49, -0.23) fitness score: RR = 0.20 (0.09, 0.47), β = -0.45 (-0.58, -0.33)). However, adjustment for childhood waist circumference reduced the effect sizes for both adult outcomes by 17%-60%.

CONCLUSION

Phenotypes of childhood muscular fitness can be used to predict adult MetS independent of cardiorespiratory fitness. Although a large proportion of the effect of childhood muscular fitness on adult MetS is potentially being mediated by child waist circumference, these data suggest that promotion of muscular fitness among children might provide additional protection against developing adult MetS.

Adiposity as a full mediator of the influence of cardiorespiratory fitness and inflammation in schoolchildren: The FUPRECOL Study

BACKGROUND AND AIMS

Studies in the paediatric population have shown inconsistent associations between cardiorespiratory fitness and inflammation independently of adiposity. The purpose of this study was (i) to analyse the combined association of cardiorespiratory fitness and adiposity with high-sensitivity C-reactive protein (hs-CRP), and (ii) to determine whether adiposity acts as a mediator on the association between cardiorespiratory fitness and hs-CRP in children and adolescents.

METHODS AND RESULTS

This cross-sectional study included 935 (54.7% girls) healthy children and adolescents from Bogotá, Colombia. The 20 m shuttle run test was used to estimate cardiorespiratory fitness. We assessed the following adiposity parameters: body mass index, waist circumference, and fat mass index and the sum of subscapular and triceps skinfold thickness. High sensitivity assays were used to obtain hs-CRP. Linear regression models were fitted for mediation analyses examined whether the association between cardiorespiratory fitness and hs-CRP was mediated by each of adiposity parameters according to Baron and Kenny procedures. Lower levels of hs-CRP were associated with the best schoolchildren profiles (high cardiorespiratory fitness + low adiposity) (p for trend <0.001 in the four adiposity parameters), compared with unfit and overweight (low cardiorespiratory fitness + high adiposity) counterparts. Linear regression models suggest a full mediation of adiposity on the association between cardiorespiratory fitness and hs-CRP levels.

CONCLUSIONS

Our findings seem to emphasize the importance of obesity prevention in childhood, suggesting that having high levels of cardiorespiratory fitness may not counteract the negative consequences ascribed to adiposity on hs-CRP.

Sex difference determined the role of sex hormone-binding globulin in obese children during short-term weight reduction program

The relationship between hyperinsulinemia and decreased sex hormone-binding globulin (SHBG) levels has been observed in obese adults and children. Weight reduction not only increased insulin sensitivity but also elevated serum SHBG levels in obese adults and children. However, the correlation between the changes in insulin resistance indices and serum SHBG concentration during weight reduction program (WRP) is not fully understood, particularly in obese children. This study is to evaluate whether SHBG level is a potential biomarker that can be used to assess insulin resistance in obese children during a short-term WRP. Forty-eight obese Taiwanese children (11.7 ± 2.2 years; 25 boys and 23 girls) participating in 8-week WRP were studied. Anthropometric measurements, lipid profiles, insulin resistance indices, and serum SHBG concentration were recorded at baseline and at the end of the WRP. The results showed body weight (BW), body mass index (BMI), body fat percentage (BF%), body fat weight (BFW), and insulin resistance indices such as fasting insulin, fasting insulin to glucose ratio, homeostasis model assessment (HOMA) of insulin resistance, log (HOMA) all significantly decreased after the 8-week WRP. With respect to lipid profiles, only high-density lipoprotein cholesterol (HDL-C) levels increased in both sexes. At baseline, insulin resistance indices were inversely correlated with SHBG concentrations in girls, but not in boys. The difference in SHBG after WRP was 2.58 nmol/L (95% confidence interval [CI]: -3.51, 8.66) in boys and 0.58 nmol/L (95% CI: -5.23, 6.39) in girls. There was a trend toward increased serum SHBG levels in boys (P = .39) and girls (P = .84) after weight loss, but a significantly negative correlation between the change in SHBG and in each of the insulin resistance indices only in the girls after adjusting age and ΔBFW during WRP.In conclusion, short-term WRP has the potential effects of decreased BW, BMI, BF%, and BFW, as well as increased serum HDL-C levels and insulin sensitivity in obese Taiwanese children. Although serum SHBG levels moderately increased in both sexes during short-term WRP, measuring the change in SHBG concentrations might be a potential biomarker to evaluate improvement in insulin resistance in girls only, and not in boys.

School-Based Interventions to Improve Cardiorespiratory Fitness in Adolescents: Systematic Review with Meta-analysis

BACKGROUND

School-based intervention can contribute to the promotion of cardiorespiratory fitness (CRF) in adolescents. However, it is neces sary to systematize how intervention strategies and the methodological characteristics of studies influence the effects of CRF interventions.

OBJECTIVE

A meta-analysis review of school-based intervention studies aimed at increasing CRF in adolescents (10-19 years of age) was conducted.

METHODS

A search for studies was conducted using the Medline, Web of Science, LILACS, PsycINFO, Embase, Scopus, SPORTDiscus and Cochrane databases and the reference lists of the selected studies. The peer selection process included consideration of school-based randomized or non-randomized controlled trials with a duration ≥12 weeks published in English, Portuguese or Spanish, and with some CRF measures. The methodological quality of the studies was also assessed. The standardized mean differences (SMDs) and 95 % confidence intervals (95 % CIs) were calculated as an effect measure.

RESULTS

Forty publications of 30 interventions were included in the review, and 25 of these were meta-analysed. The effects of CRF interventions were moderate and significant (SMD = 0.68, 95 % CI 0.45-0.90), with high heterogeneity (I (2) = 97 %). The effect size varied significantly according to the age group, sample size, intervention environment, strategies in experimental groups, CRF priority in the study, CRF test and indicator, session length, weekly frequency, intervention duration and presentation of results by sex.

CONCLUSION

Interventions in the school environment seem to have a positive effect on CRF among adolescents, but there is high heterogeneity between studies. Some intervention characteristics can explain better effects on CRF (e.g. exercise sessions in addition to physical education classes; primary focus on this outcome; combination of aerobic and resistance exercises; classes lasting ≥60 min; frequency of three times weekly; and intensity control).