Physical activity, cardiorespiratory fitness, and the metabolic syndrome in youth

Exercise blood pressure, cardiorespiratory fitness, fatness and cardiovascular risk in children and adolescents

Cardiovascular disease remains the leading cause of mortality on a global scale. Individuals who possess risk factors for cardiovascular disease, such as high blood pressure (BP) and obesity, face an elevated risk of experiencing organ-specific pathophysiological changes. This damage includes pathophysiological changes in the heart and peripheral vascular systems, such as ventricular hypertrophy, arterial stiffening, and vascular narrowing and stenosis. Consequently, these damages are associated with an increased risk of developing severe cardiovascular outcomes including stroke, myocardial infarction, heart failure, and coronary heart disease. Among all the risk factors associated with cardiovascular disease, high blood pressure emerges as the most prominent. However, conventional resting BP measurement methods such as auscultatory or oscillometric methods may fail to identify many individuals with asymptomatic high BP. Recently, exercise BP has emerged as a valuable diagnostic tool for identifying real (high) blood pressure levels and assessing underlying cardiovascular risk, in addition to resting BP measurements in adults. Furthermore, numerous established factors, such as low cardiorespiratory fitness and high body fatness, have been confirmed to contribute to exercise BP and the associated cardiovascular risk. Modifying these factors may help reduce high exercise BP and, consequently, alleviate the burden of cardiovascular disease. A significant body of evidence has demonstrated cardiovascular disease in later life have their origins in early life. Children and adolescents with these cardiovascular risk factors also possess a greater propensity to develop cardiovascular diseases later in life. Nevertheless, the majority of previous studies on the clinical utility of exercise BP have been conducted in middle-to-older aged populations, often with pre-existing clinical conditions. Therefore, there is a need to investigate further of the factors influencing exercise BP in adolescence and its association with cardiovascular risk in early life. Our previously published work showed that exercise BP is a potential useful method to detect adolescents with increased cardiovascular risk. Children and adolescents with cardiovascular risk factors are more likely to develop cardiovascular diseases later in life. However, previous studies on the clinical utility of exercise BP have largely focused on middle-to-older aged populations with pre-existing clinical conditions. Therefore, there is a need to investigate further the factors influencing exercise BP in adolescence and its association with future cardiovascular risk. Our previous studies, which focused on exercise BP measured at submaximal intensity, have shown that exercise BP is a potentially useful method for identifying adolescents at increased cardiovascular risk. Our previous findings suggest that improving cardio-respiratory fitness and reducing body fatness may help to reduce the risk of developing cardiovascular disease and improve overall cardiovascular health. These findings have important implications for the development of effective prevention and early detection strategies, which can contribute to improved public health outcomes.

Parental support for physical activity and children's physical activities: a cross-sectional study

BACKGROUND

Physical activity (PA) in school-aged children is imperative for physical and mental development. However, there has been reduced PA among children in recent years owing to environmental changes, resulting in declining physical strength and athletic ability. Although parents' and children's PA has been found to be correlated, the specific parental caregiving attitudes associated with children's actual levels of PA during school-age years remain unknown. Therefore, this study aimed to examine the relationship between parental support for PA and children's levels of PA.

METHODS

In 2017, a self-reported questionnaire survey was administered to 1,515 third-grade students (8-9 years old) and their caregivers in Nagoya, Aichi, a major metropolitan area in Japan. The main items surveyed included the attitudes of children and parents towards PA and the children's actual PA level. Multiple regression analysis was conducted with parental involvement related to PA as the explanatory variable and children's PA as the objective variable.

RESULTS

In total, 717 children with valid responses were included in the analysis. The mean age of the children was 9.08 ± 0.33 years; 366 (51.0%) were boys, and 351 (49.0%) were girls. For moderate-to-vigorous and vigorous PA, PA levels tended to be significantly higher in children whose parents provided logistic support such as enrolling their children in a sports club. However, for moderate PA and walking, PA levels tended to be significantly higher in children whose parents used community resources. Modeling and limiting sedentary activities were not associated with children's PA.

CONCLUSIONS

The results of this study suggest that direct parental assistance for PA such as logistic support encourages children to engage in moderate-to-vigorous PA; in addition, parental use of community resources may encourage children to engage in moderate and light PA such as walking. Conversely, indirect and negative involvement such as modeling and limiting sedentary activities were not associated with children's PA. Therefore, logistic support may need to be strengthened to encourage moderate-to-vigorous and vigorous PA, which is important for children's health.

Early-Life Metabolic Traits and Physical Fitness in Tarahumara, Mennonite, and Mestizo Adolescents from Northern Mexico

The WHO identifies high BMI, high blood pressure, and high fasting plasma glucose as chronic disease risk factors, whereas physical fitness is identified as a protective behavioral factor. This study responds to the rising interest in assessing metabolic factors and physical activity within young populations of Mestizo, Tarahumara, and Mennonite from Chihuahua Mexico, due to its strong relationship with disease development and low well-being. A cross-sectional study was conducted with 201 teenagers from rural towns in Northern Mexico, and relationships between physical fitness and cardio-metabolic risk related to anthropometric, glycolipid, and vascular function factors were assessed. ANOVA-tested differences among ethnic groups using physical fitness as a grouping variable and measures of cardio-metabolic risks were used as dependent variables. A stepwise regression analysis allowed us to identify the best predictors for physical fitness. Clinical risk factors were analyzed by ethnic group and sex. No differences were found among ethnic groups in physical fitness and cardio-metabolic health risks; sex differentiated higher health risks related to behavioral factors, since young women showed lower physical fitness across ethnicities. Clinically, the Mestizo sample showed higher numbers of individuals with one risk factor. Mennonites showed a high frequency of anthropometric and fitness health risks with low glycolipid and vascular risks. Tarahumara had fewer risk factors as compared with both Mestizo and Mennonite. Rural populations are harder to reach, both for health assessment and intervention; health professionals must work close to local community organizations to gain access.

Muscle Quality Index in Morbidly Obesity Patients Related to Metabolic Syndrome Markers and Cardiorespiratory Fitness

BACKGROUND

Muscle quality index (MQI) is an emerging health indicator obtained by dividing handgrip strength by body mass index (BMI) that needs to be studied in morbidly obese patients (defined by BMI ≥ 35 kg/m²).

OBJECTIVE

To determine the association between MQI, metabolic syndrome (MetS) markers, and cardiorespiratory fitness (CRF), and as a second objective to determine the potential mediation role of MQI in the relationship between abdominal obesity and systolic blood pressure (SBP) in this sample.

METHODS

This cross-sectional study included 86 severely/morbidly obese patients (age = 41.1 ± 11.9 y, nine men). MQI, metabolic syndrome markers, CRF, and anthropometric parameters were measured. Two groups were developed according to MQI; High-MQI (n = 41) and Low-MQI (n = 45).

RESULTS

The Low-MQI group reported higher abdominal obesity (High-MQI: 0.7 ± 0.1 vs. Low-MQI: 0.8 ± 0.1 WC/height; p = 0.011), SBP (High-MQI: 133.0 ± 17.5 vs. Low-MQI: 140.1 ± 15.1 mmHg; p = 0.048), and lower CRF (High-MQI; 26.3 ± 5.9 vs. Low-MQI; 22.4 ± 6.1 mL/kg/min, p = 0.003) than the High-MQI group. Waist-to-height ratio (β: -0.07, p = 0.011), SBP (β: -18.47, p = 0.001), and CRF (β: 5.21, p = 0.011) were linked to MQI. In a mediation model, the indirect effect confirms that MQI is a partial mediator of the association between abdominal obesity with SBP.

CONCLUSIONS

MQI in morbidly obesity patients reported an inverse association with MetS markers and a positive association with CRF (VO2_max). It mediates the relationship between abdominal obesity and SBP.

Physical fitness in children and adolescents with inflammatory bowel disease: protocol for a case-control study

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic disorder of the gastrointestinal tract, associated with adverse health consequences that may adversely influence physical activity and body composition in youth. These effects may lead to changes in physical fitness, which is positively associated with health-related outcomes. The aim is to assess health-related physical fitness levels in paediatric patients with IBD and to compare these levels with those in healthy matched controls.

METHODS AND ANALYSIS

This trial is a bicentric case-control study. Fifty paediatric patients with IBD and 50 matched healthy controls will be recruited (1:1), and physical fitness levels (cardiorespiratory fitness, muscular strength, speed/agility and flexibility) will be assessed. The primary outcome is cardiorespiratory fitness, which will be compared between children and adolescents with IBD and healthy controls matched for age, sex and body mass index class. We will assess whether the two groups differ with respect to other physical fitness components and cardiovascular risk in adulthood according to sex-specific cut-offs for a healthy cardiorespiratory fitness level in adolescents. We will identify relationships between physical fitness and characteristics of IBD, quality of life and daily physical activity.

ETHICS AND DISSEMINATION

This study was approved by the Research Ethics Committee (Comité de Protection des Personnes, Centre-Ouest I, Tours, France; No 2019-A02651-56) and was declared to the Commission Nationale de l'Informatique et des Libertés. All procedures will be performed according to the ethical standards of the 1975 Declaration of Helsinki, as revised in 2008, and the European Union's Guidelines for Good Clinical Practice. Written informed consent will be obtained from the youths and their parents. Research findings will be disseminated in peer-reviewed journals and scientific meetings, as well as in social media and IBD family support groups.

TRIAL REGISTRATION NUMBER

NCT04647578.

Longitudinal Association between Weight Status, Aerobic Capacity, Muscular Strength, and Endurance among New York City Youth, 2010-2017

Background: Child weight status is inversely associated with fitness, but less is known about this relationship across fitness domains. This study examined the longitudinal association between weight status and fitness domains in a large, diverse sample of children. Methods: Data were drawn from the New York City Fitnessgram (2010-2011 to 2017-2018). Height and weight were collected annually and converted to weight status using Centers for Disease Control and Prevention growth charts. Aerobic capacity, muscular strength, and endurance were measured as age and sex standardized z-scores based on the fitness performance tests. Repeated-measures multilevel models were run testing the association between weight status and 1-year lagged fitness domains. Results: The sample included 917,554 children (51.8% male, 39.3% Hispanic, 29.9% non-Hispanic Black, 13.9%, 4.7%, and 1.7% class I, II, and III obesity, respectively). For each fitness domain, fitness scores decreased with increasing weight status across all demographic categories, with the lowest fitness scores observed in children with the most severe obesity, and highest magnitude of effects for aerobic capacity, and particularly among boys, non-Hispanic Whites, and older youth. For example, compared with youth with healthy weight, youth with overweight had 0.28 standard deviation lower aerobic capacity performance [confidence interval (95% CI): -0.29 to -0.28], followed by class 1 obesity (β = -0.57, 95% CI: -0.58 to -0.57), class 2 obesity (β = -0.88, 95% CI: -0.88 to -0.88), and class 3 obesity (β = -1.19, 95% CI: -1.20 to -1.18). Conclusions: Compared with youth with healthy weight, youth at every other weight status had lower subsequent fitness, with the magnitude of the relationship increasing as weight status increased. Future research should examine interventions targeting aerobic capacity to reduce fitness disparities.

COVID-19 and screen-based sedentary behaviour: Systematic review of digital screen time and metabolic syndrome in adolescents

Aim

The COVID-19 pandemic has prompted governments around the globe to implement various restriction policies, including lockdown, social distancing, and school closures. Subsequently, there has been a surge in sedentary behaviour particularly screen time (ST) together with a significant decline in physical activity that was more marked amongst children and adolescents. Excessive screen exposure in adolescents has been correlated with cardio-metabolic risk factors including obesity, hypertension, high cholesterol, and glucose intolerance that may have adverse morbidity and mortality implications in adulthood. Thus, the current study aimed to synthesize the literature on the relationship between ST of various types and the risk of metabolic syndrome (MetS) in adolescents in the context of the COVID-19 pandemic.

Methods

In August 2021, a systematic search of the literature was undertaken using electronic databases: PubMed, PsycINFO, and the Cochran library. Studies were considered if they met the following key eligibility criteria: (i) Measure of ST as an exposure (TV, computer, videogames, internet, smartphone, tablet), using quantified duration/frequency either self-reported or observed; (ii) Measure of MetS as an outcome with standard definition and/or criteria required to establish MetS diagnosis. The Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies was used to assess the risk of bias.

Results

A total of ten studies met the inclusion criteria, and the majority were cross sectional studies. Most studies met fair bias scoring. Overall, the review revealed considerable evidence that suggests a significant negative association between ST and components of MetS among adolescents with dose-response association.

Conclusion

During the pandemic, screen usage may become more prevalent through periods of school closures, lockdowns, social isolation, and online learning classes. Public health policies and health promotion strategies targeting parents are needed to raise awareness of the adverse health effects associated with screen-based sedentary behaviour as a precursor of NCDs. Parent or home focused interventions might be effective in limiting adolescents’ screen exposure, alternatively substituted with an appropriate level of physical activity.

PROSPERO registration number

PROSPERO 2021 CRD42021272436.

Cardiorespiratory fitness, screen time and cardiometabolic risk in South Brazilian school children

Background: Cardiorespiratory fitness (CRF) is considered a beneficial effect of physical activity (PA). PA and excessive screen time have implications for cardiometabolic risk. Objective: To verify the association between screen time and CRF grouped by cardiometabolic risk factors. Subjects and methods: Cross-sectional study evaluated 1,253 schoolchildren (54.2% girls) aged seven to 17 years from southern Brazil. The outcomes were body mass index (BMI), waist circumference (WC), systolic (SBP) and diastolic (DBP) blood pressure, glucose, and lipid profile. Exposure was a combined variable of self-reported screen time (television, video game, computer) and CRF. Results: The main result is that CRF had a more consistent association with anthropometric factors than with metabolic variables. Low CRF students, regardless of screen time, showed a 15% increase in the risk of elevated WC (p < 0.001) and a 24% (<2h screen time) and 19% (≥2h) higher risk of overweight (p < 0.001). Second, the increase in SBP was associated with a combination of the two risk factors, ≥2h screen time/low CRF was associated with a 7% increase in elevated SBP (p = 0.025). Conclusion: Low CRF was a risk factor for elevated BMI and WC, regardless of screen time. High screen time and low CRF were associated with higher SBP values.

Parents' and Children's (6-12 Years Old) Physical Activity Association: A Systematic Review from 2001 to 2020

Worldwide, studies reveal that a significant proportion of adults and children do not meet the recommended guidelines for physical activity (PA). Therefore, it is crucial that proxy determinants for child physical activity enhancement could be identified. Parents have been considered to have a key role in child adherence to physical activity. Thus, this systematic review aimed to identify association between parents’ and children’s PA. The search of scientific papers was conducted from 31 October 2020 until 31 January 2021, on the Web of Science, Scopus, Psycinfo, SportDiscus, and Pubmed databases. The PRISMA protocol was used. Findings indicate a consistent association between parents’ and children’s (6–12 years old) PA. Despite the imbalance of the number of assessed fathers and mothers with the latter clearly overrepresented, a trend towards the same gender dyads on PA significant and positive association (father/son, mother/daughter) was evidenced. Results support the relevant importance of parents’ PA as role modeling (either explicitly or implicitly) for children’s PA. Besides, results revealed the importance of promoting PA in family for the enhancement of children’s PA. Moreover, and given the positive impact of exerting PA with the children on children’s PA, parents should spend more time practicing PA with their children, especially on MVPA and meeting the recommended guidelines for PA. Future studies should highlight the role of mediator variables on this interaction process, extending the knowledge on the contribution of other factors to the requested enhancement of children adherence to PA practice.

Accuracy of perceived physical activity and fitness levels among childhood cancer survivors

BACKGROUND

Childhood cancer survivors do not engage in sufficient physical activity and have low fitness levels. Perceived physical activity and fitness levels may influence survivors' engagement in health behaviours. We aimed to investigate survivors' perceptions of physical activity and fitness levels and identify how accurate their perceptions were. We further explored survivors' attitudes toward physical activity, including perceived importance and desire to increase activity levels.

PROCEDURE

We recruited 116 childhood cancer survivors (8-18 years) and assessed their perceived physical activity levels using a questionnaire and the Godin's Leisure Score Index. Accuracy of their perceptions was established by comparing their perceived physical activity levels with the recommended guidelines. Survivors reported their perceived fitness levels using the International Fitness Scale. We compared survivors' perceptions with their performance on the 6-minute walk test using weighted Cohen's kappa to determine interrater agreement between perceived and objectively measured fitness.

RESULTS

Most survivors did not meet the physical activity guidelines (<420 min/week). One-third incorrectly perceived whether their self-reported physical activity levels were appropriate (84% underestimated, while 16% overestimated). Survivors had average fitness and were inaccurate at perceiving their fitness level. Survivors highly valued the importance of being able to do physical activity, and 89% reported a desire to increase their physical activity.

CONCLUSIONS

Our results reveal that many survivors are not accurate when perceiving their physical activity and fitness levels. Emphasising the need for objective fitness assessments, and patient education in clinical practice may support survivors to accurately perceive their physical activity and fitness levels, thus improving health behaviours.

Cardiorespiratory fitness, fatness, and the acute blood pressure response to exercise in adolescence

OBJECTIVE

Exaggerated exercise blood pressure (BP) is associated with cardiovascular risk factors in adolescence. Cardiorespiratory fitness and adiposity (fatness) are independent contributors to cardiovascular risk, but their interrelated associations with exercise BP are unknown. This study aimed to determine the relationships between fitness, fatness, and the acute BP response to exercise in a large birth cohort of adolescents.

METHODS

2292 adolescents from the Avon Longitudinal Study of Parents and Children (aged 17.8 ± 0.4 years, 38.5% male) completed a sub-maximal exercise step test that allowed fitness (VO2 max ) to be determined from workload and heart rate using a validated equation. Exercise BP was measured immediately on test cessation and fatness calculated as the ratio of total fat mass to total body mass measured by DXA.

RESULTS

Post-exercise systolic BP decreased stepwise with tertile of fitness (146 (18); 142 (17); 141 (16) mmHg) but increased with tertile of fatness (138 (15); 142 (16); 149 (18) mmHg). In separate models, fitness and fatness were associated with post-exercise systolic BP adjusted for sex, age, height, smoking, and socioeconomic status (standardized β: -1.80, 95%CI: -2.64, -0.95 mmHg/SD and 4.31, 95%CI: 3.49, 5.13 mmHg/SD). However, when fitness and fatness were included in the same model, only fatness remained associated with exercise BP (4.65, 95%CI: 3.69, 5.61 mmHg/SD).

CONCLUSION

Both fitness and fatness are associated with the acute BP response to exercise in adolescence. The fitness-exercise BP association was not independent of fatness, implying the cardiovascular protective effects of cardiorespiratory fitness may only be realized with more favorable body composition.

Scaling up Action Schools! BC: How Does Voltage Drop at Scale Affect Student Level Outcomes? A Cluster Randomized Controlled Trial

Action Schools! BC (AS! BC) was scaled-up from an efficacy trial to province-wide delivery across 11 years (2004-2015). In this study we: (1) describe strategies that supported implementation and scale-up; (2) evaluate implementation (teachers' physical activity (PA) delivery) and student's PA and cardiorespiratory fitness (CRF) within a cluster randomized controlled trial during years 2 and 3 of scale-up; and (3) assess relationships between teacher-level implementation and student-level outcomes. We classified implementation strategies as process, capacity-building or scale-up strategies. Elementary schools (n = 30) were randomized to intervention (INT; 16 schools; 747 students) or usual practice (UP; 14 schools; 782 students). We measured teachers' PA delivery (n = 179) using weekly logs; students' PA by questionnaire (n = 30 schools) and accelerometry (n = 9 schools); and students' CRF by 20-m shuttle run (n = 25 schools). INT teachers delivered more PA than UP teachers in year 1 (+33.8 min/week, 95% CI 12.7, 54.9) but not year 2 (+18.8 min/week, 95% CI -0.8, 38.3). Unadjusted change in CRF was 36% and 27% higher in INT girls and boys, respectively, compared with their UP peers (year 1; effect size 0.28-0.48). Total PA delivered was associated with change in children's self-reported MVPA (year 1; r = 0.17, p = 0.02). Despite the 'voltage drop', scaling-up school-based PA models is feasible and may enhance children's health. Stakeholders must conceive of new ways to effectively sustain scaled-up health promoting interventions if we are to improve the health of students at a population level. Clinical Trials registration: NCT01412203.

Mediation role of cardiorespiratory fitness on the association between fatness and cardiometabolic risk in European adolescents: The HELENA study

PURPOSE

This study was aimed to analyze the mediation role of cardiorespiratory fitness (CRF) on the association between fatness and cardiometabolic risk scores (CMRs) in European adolescents.

METHODS

A cross-sectional study was conducted in adolescents (n = 525; 46% boys; 14.1 ± 1.1 years old, mean ± SD) from 10 European cities involved in the Healthy Lifestyle in Europe by Nutrition in Adolescence study. CRF was measured by means of the shuttle run test, while fatness measures included body mass index (BMI), waist to height ratio, and fat mass index estimated from skinfold thicknesses. A clustered CMRs was computed by summing the standardized values of homeostasis model assessment, systolic blood pressure, triglycerides, total cholesterol/high-density lipoprotein cholesterol ratio, and leptin.

RESULTS

Linear regression models indicated that CRF acted as an important and partial mediator in the association between fatness and CMRs in 12-17-year-old adolescents (for BMI: coefficients of the indirect role β = 0.058 (95% confidence interval (95%CI): 0.023-0.101), Sobel test z = 3.11 (10.0% mediation); for waist to height ratio: β = 4.279 (95%CI: 2.242-7.059), z =3.86 (11.5% mediation); and for fat mass index: β = 0.060 (95%CI: 0.020-0.106), z = 2.85 (9.4% mediation); all p < 0.01).

CONCLUSION

In adolescents, the association between fatness and CMRs could be partially decreased with improvements to fitness levels; therefore, CRF contribution both in the clinical field and public health could be important to consider and promote in adolescents independently of their fatness levels.

Interaction Effect of the Mediterranean Diet and an Obesity Genetic Risk Score on Adiposity and Metabolic Syndrome in Adolescents: The HELENA Study

Obesity and metabolic syndrome (MetS) are worldwide major health challenges. The Mediterranean diet (MD) is associated with a better cardiometabolic profile, but these beneficial effects may be influenced by genetic variations, modulating the predisposition to obesity or MetS. The aim was to assess whether interaction effects occur between an obesity genetic risk score (obesity-GRS) and the MD on adiposity and MetS in European adolescents. Multiple linear regression models were used to assess the interaction effects of an obesity-GRS and the MD on adiposity and MetS and its components. Interaction effects between the MD on adiposity and MetS were observed in both sex groups (p < 0.05). However, those interaction effects were only expressed in a certain number of adolescents, when a limited number of risk alleles were present. Regarding adiposity, a total of 51.1% males and 98.7% females had lower body mass index (BMI) as a result of higher MD adherence. Concerning MetS, only 9.9% of males with higher MD adherence had lower MetS scores. However, the same effect was observed in 95.2% of females. In conclusion, obesity-related genotypes could modulate the relationship between MD adherence and adiposity and MetS in European adolescents; the interaction effect was higher in females than in males.

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.

Relationship Between Daily Sedentary Behaviors and Metabolic Syndrome in Middle-Aged Adults: Results from a Health Survey in Taean-Gun, Republic of Korea

Background: It is unclear whether sedentary behavior is associated with metabolic risk, being independent of physical activity and other possible confounders. This study aimed to evaluate an association between sedentary behaviors and metabolic syndrome (MetS). Methods: A community-based cross-sectional study was conducted in a total of 987 Korean adults aged 40 years or older. Information on study variables, including physical activity, awake and sitting time, and components of MetS, was collected by a self-administered questionnaire, physical measurement, and laboratory test. MetS was defined according to the modified National Cholesterol Education Program's Adult Treatment Panel III and Korean Society for the Study of Obesity. Multiple logistic regression analysis was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) for MetS associated with absolute sitting time, high sedentary ratio (>0.5), and other selected covariates, including age, sex, smoking, alcohol intake, educational attainment, daily meal times, regular exercise, intensity of physical activities, and sleep and nap duration. Results: After considering other selected variables, the risk of MetS was found to be higher by about 54% among subjects who had a higher sedentary ratio (OR: 1.54, 95% CI: 1.04-2.28). Every hour increase in sitting time was associated with increased risk of MetS (OR: 1.05, 95% CI: 0.99-1.11) with borderline significance (P = 0.119). Conclusions: Sedentary behavior was independently associated with an increased risk of MetS, suggesting that efforts to reduce the sedentary time might be also important for metabolic health in addition to encouraging adequate physical exercise. Clinical trial number is not applicable to this study.

Association between parent and child physical activity: a systematic review

Background

Childhood represents an important life stage for establishment of physical activity (PA) habits. Parents are assumed to play an important role in influencing children’s PA. Earlier reviews have mainly focused on parental modelling, encouragement, and support for PA, rather than the actual PA levels of parents. Therefore, the purpose of this review was to systematically summarize the evidence on the relationship between parent and child PA.

Methods

Papers were identified using electronic databases and manual searches of reference lists. Papers reporting on associations between objectively measured child PA and at least one measure of parental PA were included. The quality of the papers was assessed using a modified version of the ROBINS-I tool. For interpretation of the results across studies, we produced albatross plots for all studies combined and by age-groups, sex of the parents, sex of the child, methodology of assessment of parental PA, and type of PA.

Results

Thirty-nine papers were included with sample size of parent-child dyads ranging from 15 to 1267 (mean = 319 dyads, median = 227 dyads). The majority of studies were published from 2008 to 2018 and used accelerometry to assess PA. Most of the studies were classified as having moderate, serious, or critical risk of bias. The albatross plot for all studies combined showed that the clear majority of studies observed a positive relationship between parent and child PA. The plot suggested an average magnitude of correlation across studies to be around 0.13, and the overall impression was that this was fairly similar across child age-groups and gender of parent-child dyads. Studies using objective assessment of parental PA showed stronger relationship between parent and child PA compared with studies using self-report (average magnitude of correlation around 0.16 vs 0.04 respectively). No clear evidence was found for the strength of relationship being dependent on type of PA measure of parent and child (total PA, moderate-to-vigorous PA, steps), however, the relationship for light PA appeared weaker.

Conclusion

This systematic review showed that the clear majority of studies observed a weak positive relationship between parent and child PA regardless of age of the child, the gender of the parent-child dyad, and type of PA.

Trial registration

Registration in PROSPERO: CRD42019093462.

An Application of Metabolic Syndrome Severity Scores in the Lifestyle Risk Assessment of Taiwanese Adults

A metabolic syndrome (MS) diagnosis was made when the criteria for three or more of five MS components were met. Due to some limitations in the traditional MS criteria, however, different health care societies have sought to develop applicable MS scoring systems instead. Continuous MS scores can be of meaningful value in the prevention, diagnosis, and treatment of MS at different life stages. Relatedly, this study used a database for 27,748 subjects aged 20 to 64 years who received health checks at a health screening institution in Taiwan from 2010 to 2015 to a similar end. Five components of MS (waist circumference, fasting plasma glucose, blood pressure, fasting triglycerides, and high-density lipoprotein) were used to formulate an MS severity score in different gender and age stratums, which was then used to evaluate the risks of various lifestyle habits. Those estimates were then compared with the results for traditional MS diagnosis. The MS severity scores for some behaviors relating to smoking, drinking, physical activity, and sweetened beverage consumption were found to have changed from 0.03 to 0.2; however, a logistic regression analysis with dichotomous diagnosis did not indicate significant links between these behaviors and MS. The models established by the MS severity scores can identify the risk factors for MS in a more sensitive manner than the traditional MS diagnosis can, especially with respect to specific lifestyle habits. MS severity score can serve as an indicator to explore the potential risk factors for subclinical conditions in the early stages of MS.

Cardiorespiratory Fitness, Physical Activity, and Insulin Resistance in Children

PURPOSE

Few studies have investigated the independent and joint associations of cardiorespiratory fitness (CRF) and body fat percentage (BF%) with insulin resistance in children. We investigated the independent and combined associations of CRF and BF% with fasting glycemia and insulin resistance and their interactions with physical activity (PA) and sedentary time among 452 children age 6 to 8 yr.

METHODS

We assessed CRF with a maximal cycle ergometer exercise test and used allometrically scaled maximal power output (Wmax) for lean body mass (LM) and body mass (BM) as measures of CRF. The BF% and LM were measured by dual-energy X-ray absorptiometry, fasting glycemia by fasting plasma glucose, and insulin resistance by fasting serum insulin and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). The PA energy expenditure, moderate-to-vigorous PA (MVPA), and sedentary time were assessed by combined movement and heart rate sensor.

RESULTS

Wmax/LM was not associated with glucose (β = 0.065, 95% confidence interval [CI] = -0.031 to 0.161), insulin (β = -0.079, 95% CI = -0.172 to 0.015), or HOMA-IR (β = -0.065, 95% CI = -0.161 to 0.030). Wmax/BM was inversely associated with insulin (β = -0.289, 95% CI = -0.377 to -0.200) and HOMA-IR (β = -0.269, 95% CI = -0.359 to -0.180). The BF% was directly associated with insulin (β = 0.409, 95% CI = 0.325 to 0.494) and HOMA-IR (β = 0.390, 95% CI = 0.304 to 0.475). Higher Wmax/BM, but not Wmax/LM, was associated with lower insulin and HOMA-IR in children with higher BF%. Children with higher BF% and who had lower levels of MVPA or higher levels of sedentary time had the highest insulin and HOMA-IR.

CONCLUSIONS

Children with higher BF% together with less MVPA or higher levels of sedentary time had the highest insulin and HOMA-IR. Cardiorespiratory fitness appropriately controlled for body size and composition using LM was not related to insulin resistance among children.

Objectively Measured Aerobic Fitness is Not Related to Vascular Health Outcomes and Cardiovascular Disease Risk In 9-10 Year Old Children

The purpose of the study was to examine whether a higher aerobic fitness in 9-10 year old children is related to superior macro and microvascular health and cardiovascular disease (CVD) risk. Ninety-six 9-10 year olds (53 boys) completed the study. Body composition was assessed from air displacement plethysmography and magnetic resonance imaging. Peak oxygen uptake (V̇O2) was assessed from a ramp-incremental cycling exercise test. Macrovascular outcomes were assessed from pulse wave analysis and pulse wave velocity (PWV) using applanation tonometry. Microvascular function was assessed from the functional microvascular reserve and skin erythrocyte flux after iontophoretic application of skin vasodilators. Assessment of CVD risk was assessed via body mass index, total body fat percentage and visceral adipose tissue, glucose, triglyceride, total cholesterol, HDL cholesterol and LDL cholesterol, while insulin resistance was calculated using Homeostatic model assessment. Aerobic fitness groups (higher vs lower) were calculated from V̇O2 peak scaled for body mass (mL·kg-0.61·min-1) and fat free mass (mL·FFM-1·min-1). Children with a higher V̇O2 peak scaled for body mass had a greater carotid to ankle PWV compared to those with lower aerobic fitness (mean ± SD: 6.08 ± 0.47 vs. 5.87 ± 0.43 m·s-1; p = 0.039), although this became non-significant when scaled for FFM (p = 0.56). No other mean differences in vascular or CVD risk health markers were present between higher and lower groups of aerobic fitness when scaled for body mass or FFM. Conclusion: Directly assessed aerobic fitness is not related to macro and microvascular health outcomes or CVD risk markers in 9-10 year olds.

Differences in Cardiorespiratory Fitness between Chinese and Japanese Children and Adolescents

Background: This study aimed to compare the difference in cardiorespiratory fitness between Chinese and Japanese children and adolescents. Methods: Participants comprised 9025 children and adolescents aged 7–18 years from China and Japan. Cardiorespiratory fitness (CRF) was measured by performance in the 20 m shuttle run test (20mSRT) and estimated maximal oxygen consumption (VO_2max). Differences in CRF between countries were evaluated by t-tests. Centile curves for the 20mSRT and VO_2max values were constructed for Chinese and Japanese children and adolescents, respectively, using the Lambda Mu and Sigma (LMS) method. Results: (1) For most of the age groups, the 20mSRT and VO_2max performances among Chinese participants were lower than among Japanese participants. (2) Japanese children had the most apparent gains in P₁₀, P₅₀, and P₉₀ VO_2max values in primary school; however, they gradually decreased in middle school. For Chinese girls, the P₁₀, P₅₀, and P₉₀ VO_2max values decreased gradually with age. (3) The VO_2max value among Japanese children increased; however, it decreased or remained flat among Chinese children in primary school. Conclusions: CRF among Chinese participants was lower than among Japanese participants while the VO_2max value showed different trends in primary school. Effective measures should be taken to improve CRF among children and adolescents.

Wuqinxi Qigong as an Alternative Exercise for Improving Risk Factors Associated with Metabolic Syndrome: A Meta-Analysis of Randomized Controlled Trials

Background: The improvement of living standards has led to increases in the prevalence of hypokinetic diseases. In particular, multifactorial complex diseases, such as metabolic syndrome, are becoming more prevalent. Currently, developing effective methods to combat or prevent metabolic syndrome is of critical public health importance. Thus, we conducted a systematic review to evaluate the existing literature regarding the effects of Wuqinxi exercise on reducing risk factors related to metabolic syndrome. Methods: Both English- and Chinese-language databases were searched for randomized controlled trials investigating the effects of Wuqinxi on these outcomes. Meanwhile, we extracted usable data for computing pooled effect size estimates, along with the random-effects model. Results: The synthesized results showed positive effects of Wuqinxi exercise on systolic blood pressure (SBP, SMD = 0.62, 95% CI 0.38 to 0.85, p < 0.001, I² = 24.06%), diastolic blood pressure (DBP, SMD = 0.62, 95% CI 0.22 to 1.00, p < 0.001, I² = 61.28%), total plasma cholesterol (TC, SMD = 0.88, 95% CI 0.41 to 1.36, p < 0.001, I² = 78.71%), triglyceride (TG, SMD = 0.87, 95% CI 0.49 to 1.24, p < 0.001, I² = 67.22%), low-density lipoprotein cholesterol (LDL-C, SMD = 1.24, 95% CI 0.76 to 1.72, p < 0.001, I² = 78.27%), and high-density lipoprotein cholesterol (HDL, SMD = 0.95, 95% CI 0.43 to 1.46, p < 0.001, I² = 82.27%). In addition, regression results showed that longer-duration Wuqinxi intervention significantly improved DBP (β = 0.00016, Q = 5.72, df = 1, p = 0.02), TC (β = −0.00010, Q = 9.03, df = 1, p = 0.01), TG (β = 0.00012, Q = 6.23, df = 1, p = 0.01), and LDL (β = 0.00011, Q = 5.52, df = 1, p = 0.02). Conclusions: Wuqinxi may be an effective intervention to alleviate the cardiovascular disease risk factors of metabolic syndrome.

Effectiveness of a multi-faceted intervention among elementary school children

Childhood obesity has been shown to be closely related to future obesity and comorbidities. As its prevalence and impact has increased significantly worldwide, researchers have focused on prevention and intervention. This study assessed a multifaceted intervention for elementary school children.A retrospective data collection with a cohort analysis was employed. A 16-week school-based intervention with nutritional intervention, physical activity, and behavioral education was designed and conducted by a multidisciplinary team for 1860 children aged 6 to 13 years. Basic information, anthropometrics, and physical fitness (PF) were recorded before and after the intervention. The differences compared with a reference group, and compared between subgroups, were analyzed.Significant favorable changes in body weight and composition were found. Children's height, weight, and muscle weight increased, whereas BMI, BMI z-score (zBMI), waist circumference, hip circumference, waist-hip ratio, waist-height ratio, body fat percentage, and visceral fat area decreased. Sit-ups and 800-m run time significantly improved. Girls exhibited a greater reduction in body weight outcomes; boys improved more in body composition and PF. Students with higher zBMI had a greater reduction in all anthropometrics; students with lower zBMI showed greater PF improvement, except for the 800-m run.The intervention improved weight measures, body composition, and PF. Subgroup differences suggested the need for sex- and weight-specific interventions.

Associations between dietary insulin load with cardiovascular risk factors and inflammatory parameters in elderly men: a cross-sectional study

Given the limited research on dietary insulin load (DIL), we examined DIL in relation to cardiovascular risk factors and inflammatory biomarkers in elderly men. For the present cross-sectional study, we recruited 357 elderly men. Dietary intake was assessed using FFQ. DIL was estimated by multiplying the insulin index of each food by its energy content and frequency of consumption and then summing the final value of all food items. After adjustment for covariates, a significant positive association was observed between high DIL with fasting blood sugar (FBS) levels (OR: 7·52; 95 % CI 3·38, 16·75; P=0·0001) and high-sensitive C-reactive protein (hs-CRP) (OR: 3·03; 95 % CI 1·54, 5·94; P=0·001). However, there was no association between high DIL and BMI (OR: 1·43; 95 % CI 0·75, 2·75; P=0·27), serum TAG level (OR: 0·82; 95 % CI 0·26, 2·59; P=0·73), HDL-cholesterol (OR: 2·03; 95 % CI 0·79, 5·23; P=0·13) and fibrinogen (OR: 1·57; 95 % CI 0·80, 3·06; P=0·18). Overall, elderly men with high DIL had higher FBS and hs-CRP levels than those with low DIL. Future studies are needed to clarify the association between DIL and other cardiovascular risk factors in both men and women.

Combined effect of physical activity and reduction of screen time for overweight prevention in adolescents

Abstract The main objective of this study was to identify the association between combined effect of physical activity, reduction of screen time and overweight in adolescents. The sample of this cross-sectional study consisted of 613 adolescents, aged 15-18 years living in a municipality in northeastern Brazil. Physical activity was measured using the short-version IPAQ (International Physical Activity Questionnaire), and screen time was verified through two questions about the time that, on average, interviewees watched television, played video games, used the cell phone or computer on a normal weekday and one weekend day. The predictive power and cutoff points of screen time and physical activity for the outcome of interest were identified using the Receiver Operating Characteristic (ROC) curves. Different logistic regression models were proposed, with excess weight as dependent variable. In all models, the combination of little physical activity and long screen time was used as reference. A 95% confidence interval (CI) was used. In boys, the combination of physical activity and short screen time on a weekend day was inversely associated with overweight (OR = 0.31; 0.12-0.85). The combined effect of physical activity and reduced time spent watching TV, computer screen and similar devices on a weekend day is inversely associated with overweight in boys.

Association between physical fitness and cognitive performance in 19-24 year old males

The present study aimed to explore the association between physical fitness (PF) and cognitive performance in a sample of 19-24 year old males. Two hundred and eleven young males (20.2±1.5 years) participated in the study. Cognitive functioning tasks including information processing speed and inhibitory control were measured in addition to PF and motor fitness components such as aerobic fitness, static strength, explosive strength, agility and speed. Regression analysis showed that after adjustment for potential confounders (e.g. age, socioeconomic status, adiposity and physical activity), aerobic fitness (represented by shorter time in the one-mile run) was positively associated with composite inhibitory control scores (standardized β=0.17; p=0.04) and negatively associated with ∆ Simon (standardized β= -0.21; p=0.04). Explosive strength was negatively associated with composite information processing scores (standardized β= -0.24; P=0.01), and composite inhibitory control scores (standardized β= -0.22; p=0.02). Speed of movement, agility and static strength were not associated with any of the cognitive tests. In conclusion, aerobic fitness and explosive strength but not speed, agility or static strength might be indicators of underlying cognitive functioning tasks in 19-24 year old males.

Movement behaviors and cardiometabolic risk in schoolchildren

Growing evidence has accumulated in recent years showing that movement behaviors have important implications for health in children, especially for cardiovascular health, whose risk factors could track from childhood to adulthood. However, these findings are mixed and inconsistent in children. The aim of this study was to examine the relationship between different movement behaviors (sedentary behavior, physical activity and sleep duration) and cardiometabolic risk in schoolchildren. The study shows cross-sectional results of baseline measurement from 146 Spanish schoolchildren, aged 8-to-11 years old, participating in the MOVI-2 study. Movement behaviors were determined using accelerometry combined with self-reported sleep time. Cardiometabolic risk was assessed using a validated metabolic syndrome index. Logistic regression analysis showed that higher levels of vigorous physical activity (OR = 0.110, p = 0.004) and sleeping more than 9 hours (OR = 0.269, p = 0.015) could be protective factors against metabolic syndrome risk in children. ANCOVA analysis showed associations between vigorous physical activity and waist circumference (p < 0.001), and sleep time with insulin resistance (p = 0.017) and lipid profile (p = 0.035). No association was observed between light and moderate physical activity, sedentary behavior and metabolic syndrome (index and components). No statistically significant differences were found for blood pressure and any of the movement behaviors. Our data suggest that both the amount of vigorous physical activity accumulated and sleep duration are independently associated with higher cardiometabolic risk in children.

Making a Case for Cardiorespiratory Fitness Surveillance Among Children and Youth

We review the evidence that supports cardiorespiratory fitness (CRF) as an important indicator of current and future health among school-aged children and youth, independent of physical activity levels. We discuss the merit of CRF measurement for population health surveillance and propose the development of CRF guidelines to help support regional, national, and international surveillance efforts.

Life Course Effects of Socioeconomic and Lifestyle Factors on Metabolic Syndrome and 10-Year Risk of Cardiovascular Disease: A Longitudinal Study in Taiwan Adults

The objective of the study was to explore the dynamic effects of socioeconomic status (SES) and lifestyle behaviors on the risks of metabolic syndrome (MS) or cardiovascular disease (CVD) in life course. The data of 12,825 subjects (6616 males and 6209 females) who underwent repeated examinations and answered repeated questionnaires from 2006 to 2014 at the Major Health Screening Center in Taiwan, was collected and analyzed. The trajectory of trends in the subjects’ SES and lifestyle mobility over time was observed, and the effects of factors with potential impacts on health were tested and analyzed using multiple logistic regression and a generalized estimated equation model. A 10% increase in MS prevalence was observed over the nine-year period. The average Framingham CVD score for people with MS was estimated to be about 1.4% (SD = 1.5%). Except for middle-aged women, marriage was found to raise the risk of CVD, whereas increasing education and work promotions independently reduced CVD risk for the majority of subjects. However, the risk of CVD was raised by half for young men who had a job or lost a job in comparison to continuously unemployed young men. Physical activity was only found to be advantageous for disease prevention in those aged less than 40 years; increased exercise levels were useless for reducing CVD risk among older men. Alcohol drinking and betel chewing caused increased CVD risk in the old and young subjects, respectively, whereas vegetarian diets and vitamin C/E intake were helpful in preventing CVD, even if those habits were ceased in later life. For middle-aged women, getting sufficient sleep reduced CVD risk. We concluded that SES and lifestyle behaviors may have different effects on health over time, among various populations. Accordingly, suggestions can be provided to healthcare workers in designing health promotion courses for people at different life stages.

Effect of moderate-intensity exercise bouts lasting <10 minutes on body composition in sedentary Kenyan adults aged ≥50 years

BACKGROUND

Sedentary lifestyles and related morbidities are rising among adults despite existing exercise recommendations. Appealing exercise regimes yielding similar/better body composition should be sought.

OBJECTIVE

We investigated the effect of moderate-intensity exercise bouts of <10 min on body composition in previously sedentary adults.

METHODS

This unblinded study enrolled 53 healthy sedentary volunteers aged ≥50 years, randomised into one of two gender-balanced exercise interventions: (1) male and (2) female short-duration bouts (MS, n=14; FS, n = 13), and (3) male and (4) female long-duration bouts (ML, n=13; FL, n=13). Short-duration bouts entailed 5-10 min of jogging thrice daily; long-duration bouts, 30-60 min 3-5 days weekly. Body composition was determined at recruitment and 8-weekly thereafter, for 24 weeks.

RESULTS

At baseline, 14.3% of MS, 38.5% of ML, 92.3% of FS and 69.2% of FL were obese, dropping to 7.1%, 15.4%, 61.5% and 30.8%, respectively. For waist:height ratio, 64.3 % of MS, 76.9% of ML, 100% of FS and 84.6.3% of FL had ratios >0.5, dropping to 42.9%, 30.8%, 92.9% and 26.2%, respectively. While baseline MS and ML waist:hip ratio (WHR) ≥0.9 were 64.3% and 69.2%, respectively, they correspondingly dropped to 23.1% and 21.4%. The FS and FL with WHR ≥0.85 dropped from 46.2% to 15.4% and from 30.8% to 7.7%, respectively. Body composition variables improved for both sexes (all p <0.05) and mean change between exercise regimes was comparable for both sexes.

CONCLUSION

In equal cumulative times, moderate-intensity exercise bouts lasting <10 min are comparable with current 30-60 min bouts in body composition modification for adults of ≥50 years.

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

OBJECTIVES

To determine the role of physical activity intensity and bout-duration in modulating associations between physical activity and cardiometabolic risk markers.

METHODS

A cross-sectional study using the International Children's Accelerometry Database (ICAD) including 38,306 observations (in 29,734 individuals aged 4-18 years). Accelerometry data was summarized as time accumulated in 16 combinations of intensity thresholds (≥500 to ≥3000 counts/min) and bout-durations (≥1 to ≥10 min). Outcomes were body mass index (BMI, kg/m2), waist circumference, biochemical markers, blood pressure, and a composite score of these metabolic markers. A second composite score excluded the adiposity component. Linear mixed models were applied to elucidate the associations and expressed per 10 min difference in daily activity above the intensity/bout-duration combination. Estimates (and variance) from each of the 16 combinations of intensity and bout-duration examined in the linear mixed models were analyzed in meta-regression to investigate trends in the association.

RESULTS

Each 10 min positive difference in physical activity was significantly and inversely associated with the risk factors irrespective of the combination of intensity and bout-duration. In meta-regression, each 1000 counts/min increase in intensity threshold was associated with a -0.027 (95% CI: -0.039 to -0.014) standard deviations lower composite risk score, and a -0.064 (95% CI: -0.09 to -0.038) kg/m2 lower BMI. Conversely, meta-regression suggested bout-duration was not significantly associated with effect-sizes (per 1 min increase in bout-duration: -0.002 (95% CI: -0.005 to 0.0005) standard deviations for the composite risk score, and -0.005 (95% CI: -0.012 to 0.002) kg/m2 for BMI).

CONCLUSIONS

Time spent at higher intensity physical activity was the main determinant of variation in cardiometabolic risk factors, not bout-duration. Greater magnitude of associations was consistently observed with higher intensities. These results suggest that, in children and adolescents, physical activity, preferably at higher intensities, of any bout-duration should be promoted.

PHYSICAL ACTIVITY, CARDIORESPIRATORY FITNESS AND METABOLIC SYNDROME IN ADOLESCENTS

ABSTRACT Introduction: Metabolic Syndrome (MetS) has been associated with sedentary behavior, low levels of physical activity and of cardiorespiratory fitness. However, in adolescents the results are conflicting. Objective: To measure the association between sedentary behavior, physical activity, cardiorespiratory fitness and MetS in a representative sample of adolescents. Methods: The sample consisted of 1,035 adolescents (565 girls and 470 boys) between 12 and 20 years of age. Sedentary behavior was treated through recreational screen time, while information equivalent to physical activity was considered through the Physical Activity Questionnaire for Adolescents. The maximal oxygen uptake (VO2max), estimated through PACER performance, was used as an indicator of cardiorespiratory fitness. MetS was identified using the criteria of the International Diabetes Federation. Results: Adolescents of both sexes identified with MetS had significantly longer recreational screen time and lower VO2max than their unidentified MetS peers. Scores equivalent to the level of physical activity undertaken by adolescents identified and not identified with MetS were statistically similar. Probabilistically, adolescents with high recreational screen time and low VO2max had, respectively, 79% [OR = 1.79; 95% CI 1.10 – 2.82] and 95% [OR = 1.95; 95% CI 1.20 – 3.09] greater odds of being identified with MetS. Conclusion: The findings indicate consistent and significant associations between longer recreational screen time, low VO2max values and high prevalence of MetS, which suggests specific interventions designed to help minimize cardiometabolic risk exposure from a very early age. Level of Evidence III; Prognostic Studies - Investigating the Effect of a Patient's Characteristics on the Disease Outcome.

Calculating a Continuous Metabolic Syndrome Score Using Nationally Representative Reference Values

OBJECTIVE

The prevalence of metabolic syndrome in youth varies on the basis of the classification system used, prompting implementation of continuous scores; however, the use of these scores is limited to the sample from which they were derived. We sought to describe the derivation of the continuous metabolic syndrome score using nationally representative reference values in a sample of obese adolescents and a national sample obtained from National Health and Nutrition Examination Survey (NHANES) 2011-2012.

METHODS

Clinical data were collected from 50 adolescents seeking obesity treatment at a stage 3 weight management center. A second analysis relied on data from adolescents included in NHANES 2011-2012, performed for illustrative purposes. The continuous metabolic syndrome score was calculated by regressing individual values onto nationally representative age- and sex-specific standards (NHANES III). Resultant z scores were summed to create a total score.

RESULTS

The final sample included 42 obese adolescents (15 male and 35 female subjects; mean age, 14.8 ± 1.9 years) and an additional 445 participants from NHANES 2011-2012. Among the clinical sample, the mean continuous metabolic syndrome score was 4.16 ± 4.30, while the NHANES sample mean was quite a bit lower, at -0.24 ± 2.8.

CONCLUSIONS

We provide a method to calculate the continuous metabolic syndrome by comparing individual risk factor values to age- and sex-specific percentiles from a nationally representative sample.

The contribution of physical fitness to individual and ethnic differences in risk markers for type 2 diabetes in children: The Child Heart and Health Study in England (CHASE)

BACKGROUND

The relationship between physical fitness and risk markers for type 2 diabetes (T2D) in children and the contribution to ethnic differences in these risk markers have been little studied. We examined associations between physical fitness and early risk markers for T2D and cardiovascular disease in 9- to 10-year-old UK children.

METHODS

Cross-sectional study of 1445 9- to 10-year-old UK children of South Asian, black African-Caribbean and white European origin. A fasting blood sample was used for measurement of insulin, glucose (from which homeostasis model assessment [HOMA]-insulin resistance [IR] was derived), glycated hemoglobin (HbA1c), urate, C-reactive protein (CRP), and lipids. Measurements of blood pressure (BP) and fat mass index (FMI) were made; physical activity was measured by accelerometry. Estimated VO_{2 max} was derived from a submaximal fitness step test. Associations were estimated using multilevel linear regression.

RESULTS

Higher VO_{2 max} was associated with lower FMI, insulin, HOMA-IR, HbA1c, glucose, urate, CRP, triglycerides, LDL-cholesterol, BP and higher HDL-cholesterol. Associations were reduced by adjustment for FMI, but those for insulin, HOMA-IR, glucose, urate, CRP, triglycerides and BP remained statistically significant. Higher levels of insulin and HOMA-IR in South Asian children were partially explained by lower levels of VO_2max compared to white Europeans, accounting for 11% of the difference.

CONCLUSIONS

Physical fitness is associated with risk markers for T2D and CVD in children, which persist after adjustment for adiposity. Higher levels of IR in South Asians are partially explained by lower physical fitness levels compared to white Europeans. Improving physical fitness may provide scope for reducing risks of T2D.

The effects of a school-based physical activity intervention programme on children's executive control: The Health Oriented Pedagogical Project (HOPP)

AIMS

To assess the effects of a large school-based physical activity intervention on children's ability to resist distractions and maintain focus, known as executive control.

METHODS

A quasi-experimental design with seven intervention and two control primary schools. The Health Oriented Pedagogical Project (HOPP) intervention consisted of 45 min of physical activity a day during school time for 6-8 months in addition to the regular weekly physical education lessons. A total of 1173 children, spanning from second grade (age 7 years) to sixth grade (age 12 years) were included in the analysis. Main outcome measures were executive control was measured at baseline and 1 year after using a modified Eriksen flanker task for the younger children (second and third grades) and a computerised Stroop task for the older children (fourth, fifth, and sixth grades).

RESULTS

Both the intervention and control group showed improvements in executive control after 1 year. However, the children in the intervention group did not improve their performance more than those in the control group.

CONCLUSIONS

No positive effect of the physical activity intervention programme on children's task performance was found, suggesting that the intervention did not affect children's executive control.

Promoting physical activity and improving dietary quality of Singaporean adolescents: effectiveness of a school-based fitness and wellness program

Limited data are available on the effectiveness of the school-based structured fitness and wellness program to influence dietary quality and physical activity levels in Singaporean adolescents. The study examined if a 20-h (over 10 weeks) school-based structured fitness and wellness module affects the diet quality indices, energy intakes, physical activity levels and the associated energy expenditures in a group of healthy, male adolescents with low diet quality and physical activity levels. Participant demography, anthropometry, dietary intake and daily physical activity were obtained at the beginning, mid-point and end of the 10-week program. Physical activity levels were assessed accelerometrically over a 1-weekday period. Dietary intake were taken using a structured 7-day food diary, and diet quality assessed using the Diet Quality Index-International (DQI-I). The 31 enrolled participants (age 19.8 ± 0.6 years) with body mass index (BMI) (19.8 ± 0.6 kg/m2) followed diets of low diet quality scores (48.3 ± 9.6 out of 100) and engaged in 3.87 ± 2.00 h of physical activity daily before the start of the intervention. Their dietary quality and physical activity levels did not change significantly throughout the intervention period. They scored poorly in the moderation and overall balance components of the diet quality assessment. The physical activity duration correlated inversely to the diet quality scores. Our results suggest that the prescribed school-based fitness and wellness module was ineffective in influencing the diet quality and physical activity levels of Singaporean male adolescents with low diet quality and physical activity levels.

Does adiposity mediate the relationship between physical activity and biological risk factors in youth?: a cross-sectional study from the International Children's Accelerometry Database (ICAD)

BACKGROUND/OBJECTIVES

To model the association between accumulating 60 daily minutes of moderate-to-vigorous physical activity and a composite score of biological risk factors into a direct and an indirect effect, using abdominal obesity as the mediator.

SUBJECTS/METHODS

Cross-sectional data from the International Children's Accelerometry Database (ICAD) including 6-18-year-old children and adolescents (N=3412) from 4 countries providing at least 3 days of accelerometry-assessed physical activity. A standardized composite risk score was calculated from systolic blood pressure and fasting blood samples of insulin, glucose, triacylglycerol and inverse HDL-cholesterol. Abdominal obesity was assessed by the waist-circumference:height ratio. Two-stage regression analysis, allowing for exposure-mediator interaction, was used for the effect decomposition.

RESULTS

Participants achieving 60 daily minutes of moderate-to-vigorous physical activity had a 0.31 (95% CI: -0.39, -0.23) standard deviations lower composite risk score than those achieving less than 60 min. Modelling the associations suggested that 0.24 standard deviations (95% CI: -0.32, -0.16) was attributed to the direct effect and -0.07 (95% CI: -0.11, -0.02) to the indirect effect indicating that 22% of the total effect was mediated by central adiposity. Modelling 30 and 90 min of moderate-to-vigorous physical activity per day resulted in changes in the direct but not the indirect effect.

CONCLUSIONS

One hour of daily moderate-to-vigorous physical activity was associated with clinically relevant differences in metabolic control compared to engagement in less than this minimally recommended amount. The majority of the difference was explained by the direct effect of physical activity.International Journal of Obesity advance online publication, 31 October 2017; doi:10.1038/ijo.2017.241.

A study on the prevalence of risk factors for diabetes and hypertension among school children in Majmaah, Kingdom of Saudi Arabia

BACKGROUND

The prevalence of risk factors for diabetes and hypertension in Saudi school children has achieved epidemic proportions because of enriched lifestyles. The aim of this study is to conduct a baseline study of such risk factors in a young population at the cusp of high-end technology and material comfort.

MATERIALS AND METHODS

A cross-sectional study was done among school children using parental assisted self-questionnaires and anthropometric assessment of their vital statistics. This study, including planning, data collection and analysis, and the writing of the first draft, was conducted from March 2015 to October 2016 after ethical approval was obtained. Cluster sampling was done for the schools, and stratified randomized sampling was performed to choose a total of 794 male and female school children. SPSS software was used for data analysis.

RESULTS

It was found that 11.6% of the children had a body mass index (BMI) above the normal range. The waist-to-height ratio was elevated in 16.8% of the children. Other risk factors of note were a high prevalence of sedentary habits (43%), daily consumption of carbonated sugary drinks (36.4%), and eating at fast food restaurants most days of the week (17%).

CONCLUSIONS

This gradual buildup of risk factors for diabetes and hypertension at an early age is a morbid indicator of an epidemic whose outcome has been determined. Most of these modifiable risk factors are amenable to change through concentrated efforts to educate, train and inculcate healthy habits among children and their families.

Subjective and objective assessment of physical activity - Influence of newly diagnosed exercise induced bronchoconstriction and gender

AIM

To investigate if occurrence of newly diagnosed exercise induced bronchoconstriction (EIB) would affect adolescents' ability to assess their physical activity.

METHODS

99 selected adolescents with and 47 adolescents without self-reported exercise induced dyspnea were included. All of the 146 adolescents then performed a standardized exercise challenge test on a treadmill with dry-air inhalation to detect EIB. Free living physical activity was assessed during seven days with both accelerometer (objective assessment) and a validated activity diary (subjective assessment). Height, weight and subjective sleep were recorded.

RESULTS

Out of the 146 adolescents 49 were diagnosed with EIB. Forty-six of the adolescents with EIB (35 girls and 11 boys) and 84 of the control adolescents (45 girls and 39 boys) had complete 7 day activity diary and accelerometer data. There were no differences in age, BMI and sleep between EIB and control adolescents. Boys with EIB overestimated subjective assessment compared to objective assessment more than girls with EIB. No difference was seen between control boys and girls. Furthermore, boys with EIB reported a much higher frequency of high intensity exercise than girls with EIB, but no difference was observed between control boys and girls.

CONCLUSION

Adolescent boys with newly diagnosed EIB overestimated their physical activity compared to EIB girls. Caution may thus be used when choosing methods measuring level of physical activity in this group and especially when investigating gender differences.

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.

Relationship between Sedentariness and Moderate-to-Vigorous Physical Activity in Youth: A Multivariate Multilevel Study

This study aimed to jointly analyse moderate-to-vigorous physical activity (MVPA) and sedentariness, and their correlates, in children within their school contexts, using a multivariate multilevel approach. The sample comprises 499 Portuguese children (284 girls) from 23 schools. MVPA and sedentary time were estimated by accelerometer. A set of predictor variables from both child and school levels was tested. Overall, schools explained a small amount of the total variance in both MVPA (5.6%) and sedentariness (3.2%), and a correlation coefficient of -0.45 (p < 0.05) was found between MVPA and sedentariness at the child level. Number of siblings and socioeconomic status (SES) were significantly associated with both sedentariness (SES: β = 2.372 ± 1.183; siblings: β = -8.127 ± 2.759) and MPVA (SES: β = -1.535 ± 0.421; siblings: β = 2.822 ± 0.977), but with opposite signs. Body Mass Index (BMI) (β = -4.804 ± 1.898) and sex (male) (β = 21.561 ± 3.496) were only associated with MVPA. None of the school correlates were statistically significant in their joint effects to simultaneously explain sedentariness and MVPA. These results suggest that although MVPA and sedentariness may be different constructs, they are correlated and this should be taken into account when designing strategies to reduce children's sedentariness and increase their MVPA. In addition, the small effect of the school context on this relationship highlights the important roles of child and family characteristics.

Physical Activity, Sedentary Behavior, Cardiorespiratory Fitness and Metabolic Syndrome in Adolescents: Systematic Review and Meta-Analysis of Observational Evidence

Background

Metabolic syndrome (MetS) has been diagnosed in adolescents and among the associated factors are low levels of physical activity, sedentary behavior over long periods and low cardiorespiratory fitness. However, specifically in adolescents, studies present conflicting results. The aim of the present study was to conduct a systematic review and meta-analysis of observational studies, in order to map the association between physical activity, sedentary behavior, cardiorespiratory fitness and MetS in adolescents.

Methods

A search was performed in the databases PubMed, SPORTDiscus, LILACS and the Cochrane Library. For the meta-analysis, the odds ratio (OR) was calculated together with the respective confidence intervals (95% CI), in which the measures of effect were analyzed by dichotomous data (exposure variables) with MetS used as events.

Results

Eighteen studies were included in the meta-analysis. Primary analysis demonstrated that low levels of physical activity (OR = 1.35 [1.03 to 1.79]; p = 0.03) and low cardiorespiratory fitness (OR = 4.05 [2.09 to 7.87]; p < 0.01) were significantly associated with the development of MetS, while for sedentary behavior, represented by screen time > 2 hours/day, a significant association was not identified (OR = 1.20 [0.91 to 1.59]; p = 0.20). Subgroup analyses demonstrated that the association between low physical activity and MetS was dependent on the use of the accelerometry technique (OR = 2.93 [1.56 to 5.47]; p < 0.01). Screen time > 2 hours/day was significantly associated with MetS only on weekends (OR = 2.05 [1.13 to 3.73]; p = 0.02). With respect to cardiorespiratory fitness, a significant association with MetS was found independent of the maximal oxygen uptake (VO₂max) measurement method.

Conclusions

Low levels of physical activity, low indices of cardiorespiratory fitness and sedentary behavior, represented by screen time > 2 hours/day on weekends, were significantly associated with the development of MetS in adolescence.

The Association Between Measures of Fitness and Metabolic Health in Treatment-Seeking Youth with Obesity

BACKGROUND

Both cardiorespiratory fitness (CRF) and measures of muscular fitness are associated with metabolic syndrome in adults. However, limited information exists about these relationships in youth with severe obesity who are at increased risk of metabolic dysfunction. The purpose of this study was to examine the relationship between fitness and metabolic health in treatment-seeking youth with obesity.

METHODS

Data for this analysis were collected at the time of baseline visits at a stage 3 pediatric weight management center. Maximal voluntary contractions were obtained by using isometric hand-grip dynamometry, and CRF was obtained from a maximal treadmill test. Resting blood pressure and fasting measures of blood lipids, glucose, and insulin were used to calculate a continuous metabolic syndrome score (cMetS); homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from fasting insulin and glucose. Relationships between measures of fitness and metabolic health were evaluated by using partial correlations adjusted for age.

RESULTS

Sixty-nine participants (21 boys, 48 girls) were included in this analysis. Of these, 46% (n = 32) met the criteria for metabolic syndrome. No differences were found between boys and girls for any variable analyzed. Muscular strength was positively associated with cMetS (r = 0.35), though this association weakened after adjustment for body mass index percentile. CRF was inversely associated with homeostasis model assessment of insulin resistance (HOMA-IR) (r = -0.26) and fasting insulin (r = -0.27). Body fat percentage was positively associated with insulin (r = 0.36). No significant relationship was found between CRF and cMetS.

CONCLUSION

Contrary to previous studies, CRF was not associated with metabolic syndrome in this group. Muscular strength, however, was associated with cMetS. Notably, CRF was associated with elevated HOMA-IR, which may be seen as a precursor to metabolic syndrome. These results suggest that CRF and muscular strength influence metabolic function independently.

Physical fitness as a mediator between objectively measured physical activity and clustered metabolic syndrome in children and adolescents: The UP&DOWN study

BACKGROUND AND AIMS

The extent to which physical fitness (PF) attenuates or modifies the association between physical activity (PA) and clustered metabolic syndrome risk factors (CMetSRF) is controversial. We aimed: i) To examine the independent and combined association of objectively measured PA and PF with CMetSRF in children and adolescents; ii) To test the mediating effect of PF in the association of PA with CMetSRF.

METHODS AND RESULTS

A total of 226 children and 256 adolescents participated. Levels of PA (light, moderate, vigorous and moderate-to-vigorous [MVPA]) and PF were measured by accelerometry and ALPHA battery, respectively. Cardiorespiratory and muscular fitness values were combined in a global PF variable. A CMetSRF was computed by assessing the following variables: waist circumference, systolic blood pressure, high-density lipoprotein cholesterol, triglycerides and glucose. In children, the highest vigorous PA (β = -0.193; P = 0.003) and MVPA (β = -0.149; P = 0.025) were individually associated with lower CMetSRF, but these associations were not independent of global PF. In adolescents, the association of moderate (β = -0.123; P = 0.046) and MVPA (β = -0.147; P = 0.024) with CMetSRF was independent of PF. Among unfit adolescents, the higher time they spent in MVPA the lower CMetSRF levels were found (P = 0.032).

CONCLUSIONS

The results are suggestive of a full mediation of global PF in the association of MVPA and vigorous PA with CMetSRF in children. In adolescents, the association of higher moderate and MVPA with lower CMetSRF was independent of levels of PF, and mediation analyses suggest only a partial mediation of global PF in the association of MVPA with CMetSRF.

Active and strong: physical activity, muscular strength, and metabolic risk in children

OBJECTIVES

This study explored the associations among physical activity, muscular strength, and metabolic risk among children.

METHODS

The sample included 378 Portuguese children (213 girls; 9-11 years). Moderate-to-vigorous physical activity was assessed by accelerometry and children were classified as active (≥60 min/day) or insufficiently active (<60 min/day). Static strength was expressed as the ratio of handgrip strength/body weight and used to classify children as having high (≥P50) or low (<P50) muscular strength. Children were classified into four groups: active and high strength, active and low strength, insufficiently active and high strength, insufficiently active and low strength. A continuous metabolic risk score was computed from cardiometabolic risk factors.

RESULTS

In general, the insufficiently active and low strength group had the worst metabolic risk score, and the active and high strength group had the best. Significant differences were found within physical activity groups for metabolic risk: children classified as "active and high strength" and "insufficiently active and high strength" had better metabolic risk scores than "active and low strength" and "insufficiently active and low strength", respectively.

CONCLUSIONS

Muscular strength has a relevant role in attenuating the association between physical inactivity and metabolic risk in children; a further benefit was identified in children with high physical activity and high muscular strength.