Physical activity and cardiovascular disease risk factors in children and adolescents

Associations between Motives for Physical Exercise, Body Composition and Cardiorespiratory Fitness: A Cross-Sectional Study

Adolescents' need for some minimum amount of daily physical exercise has been widely studied so as to assist better health outcomes and to reduce future obesity rates. However, the motivations of adolescents to exercise are less well-known. This manuscript aims to analyze the motives that explain the practice of physical exercise in adolescents and the possible associations with elements of body composition and cardiorespiratory fitness. For this purpose, the Self-Report of Motives for the Practice of Physical Exercise questionnaire (AMPEF) was administered to 917 students between 13-16 years of age (50.1% girls, 49.9% boys, M age = 14.82) from Seville, Spain. Subscales Ill-Health Avoidance and Positive Health, Revitalization and Enjoyment, Strength and Endurance, and Challenge represent the participants' main reasons for practicing physical exercise. Associations between BMI and FAT % with the subscales Weight Management and Appearance (direct association) and Revitalization and Enjoyment (inverse association) were found. A direct association between cardiorespiratory fitness and Revitalization and Enjoyment, Competition, Strength, and Endurance and Challenge subscales was found for both genders. Conclusions emphasize the practice of physical exercise in adolescents due to intrinsic motives based on improving their state of health, increasing their levels of strength and endurance (boys), and achieving short-term objectives (girls).

Spanish Translation and Cultural Adaptation of the Canadian Assessment of Physical Literacy-2 (CAPL-2) Questionnaires

Background: This study aimed to translate and culturally adapt the questionnaires belonging to the Canadian Assessment of Physical Literacy-2 (CAPL-2) into Spanish and to explore the reliability for its use in children and adolescents aged from 8 to 12 years. Methods: The CAPL-2 questionnaires were translated using the translation–back-translation methodology into Spanish and adapted to the Spanish context. The test–retest reliability and internal consistency of the CAPL-2 questionnaires of this Spanish version were analysed in 57 schoolchildren from a school in the region of Extremadura (Spain). Results: High internal consistency (α = 0.730 to 0.970) and test–retest reliabilities ranging from moderate to almost perfect in the knowledge and understanding domain (ICC = 0.486 to 0.888); from substantial to almost perfect in the motivation and confidence domain (ICC = 0.720 to 0.981); and almost perfect in the daily activity domain (ICC = 0.975) were found. The test–retest correlation was significantly weak to strong (r = 0.266 to 0.815) in both the motivation and confidence and knowledge and understanding domains, except for the third predilection item and the muscular endurance question. Significant test–retest differences were observed in the first intrinsic motivation item (p = 0.027) and the knowledge and understanding domain total score (p = 0.014). Conclusion: The Spanish version of the CAPL-2 questionnaires, translated and adapted to the context, are reliable measurement tools, serving to complete the full adaptation of the CAPL-2 test battery for use in children aged 8 to 12 years.

Association between Physical Literacy and Self-Perceived Fitness Level in Children and Adolescents

Simple Summary

Alarming data on physical inactivity and sedentary lifestyles in children and young people are increasing. The level of physical fitness is considered a predictor of morbidity and comorbidities resulting from physical inactivity. Physical literacy, which includes the assessment of physical fitness, could be considered a crucial element for understanding adolescents’ health status and physical activity-related behaviours. Moreover, the self-perceived physical fitness should also be considered. Thus, this study analysed the relationship between physical literacy and self-perceived physical fitness in children and adolescents aged 8–12 years. It could be concluded that a higher level of self-perceived physical fitness would be associated with a greater level of physical literacy.

Abstract

Background: Physical fitness is considered a predictor of mortality and comorbidities resulting from physical inactivity in children and adolescents. Physical literacy provides a robust and comprehensive assessment of physical fitness. Thus, it is considered a crucial element for understanding children and adolescents’ health status and their physical activity-related behaviours. Moreover, the self-perceived fitness should also be considered. Therefore, this study aims to analyse the relationship between physical literacy and self-perceived physical fitness in children and adolescents aged 8–12 years. Methods: A single-measure cross-sectional study was conducted with 135 children and adolescents. Anthropometric measurements and the Canadian Assessment of Physical Literacy Development (CAPL-2) were applied. Descriptive statistics and correlations were calculated. The Fitness Perception Scale for Adolescents (FP VAS A) scale was also administered to assess participants’ self-perceived fitness. Results: Moderate significant correlations were found between “physical competence”, “motivation and confidence”, and the total CAPL-2 score with FP VAS A. Conclusions: The influence of motivation on self-perceived fitness has been demonstrated. Moreover, cardiorespiratory fitness could be considered one of the most relevant and influential factors in the total CAPL-2 score. It means that higher levels of self-perceived fitness would be associated with greater levels of physical literacy.

Studying biological science does not lead to adoption of a healthy lifestyle

AIMS

The lifestyle and physical activity (PA) habits of young people play a key role in the prevention of cardiovascular and metabolic diseases at older ages. The current generation of biological science students at university holds promise for better future medicine and medical technology. However, their physical fitness and lifestyle are often ignored.

METHODS

Lifestyle, PAs and common risk factors for cardiovascular disease before, and at, university were collected from 408 students using self-completed, anonymous surveys between the academic years of 2017 and 2019 from the School of Biological Sciences, University of Reading. Statistical analysis was performed using SAS® 9.4 software.

RESULTS

Among the 408 participants, 134 were male and 274 were female with a mean (SD) age of 19.6 (2.24). Approximately 19% of participants consumed alcohol beyond the safe limit of <14 units/week (112 g/week). Among them, 65% were males. Before university, 47% of students failed to meet the UK National Physical Activity Guidelines (NPAG) which increased to 56% during university with males exhibiting a steeper incline. Compared to their lifestyles before university, more students had insufficient sleep and displayed greater sedentariness during university. Moreover, 16% of students declared no engagement in PA which was greater than the value of 12% before university. Fitness perceptions worsened by 11% during university particularly for females. Statistical analysis revealed that gender, BMI and fitness perceptions were significantly correlated with PA levels. The most prevalent explanation for inadequacy in meeting NPAG was insufficient time.

CONCLUSIONS

Compared to their pre-university lifestyles, biological science students at university are more likely to adopt unhealthier behaviours with less time for exercise and prolonged sedentary behaviours, which increases the risk for cardiovascular diseases. It is important to raise awareness of their fitness perceptions and to encourage health-promoting programmes at university.

Lifestyle patterns and endocrine, metabolic, and immunological biomarkers in European adolescents: The HELENA study

OBJECTIVE

To evaluate the association of lifestyle patterns related to physical activity (PA), sedentariness, and sleep with endocrine, metabolic, and immunological health biomarkers in European adolescents.

METHODS

The present cross-sectional study comprised 3528 adolescents (1845 girls) (12.5-17.5 years) enrolled in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Cluster analysis was performed by including body composition, PA by accelerometry, self-reported sedentary behaviors, and sleep duration. We also measured endocrine, metabolic, and immunological biomarkers.

RESULTS

Three-cluster solutions were identified: (a) light-PA time, moderate-vigorous-PA time and sedentary time, (b) light-PA time, moderate-vigorous-PA time, sedentary time and sleep time, (c) light-PA time, moderate-vigorous-PA time, sedentary time and body composition. In addition, each cluster solution was defined as: "healthy," "medium healthy," and "unhealthy" according to the presented rating. Analysis of variance showed that overall the healthiest groups from the three clusters analyzed presented a better metabolic profile. A decision tree analysis showed that leptin had a strong association with cluster 3 in both boys and girls, high-density lipoprotein cholesterol had the strongest association with clusters 1 and 3 in boys. Cortisol had the strongest association with cluster 1. HOMA index (homeostatic model assessment) and C3 showed a strong association with cluster 3 in girls.

CONCLUSIONS

Our results support the existence of different interactions between metabolic health and lifestyle patterns related to PA, sedentariness, and sleep, with some gender-specific findings. These results highlight the importance to consider multiple lifestyle-related health factors in the assessment of adolescents' health to plan favorable strategies.

Physical Activity Among Native Hawaiians and Pacific Islanders: A Systematic Review and Meta-Analysis

OBJECTIVE

To examine the proportion of Native Hawaiian and Pacific Islander (NHPI) meeting recommended physical activity guidelines for Americans (PAG) and determine differences in physical activity (PA) by sex and between NHPI and Asians when data are disaggregated.

DESIGN

Systematic review and meta-analysis.

SETTING

Articles identified in CINAHL, The Cochrane Library, Embase, PsychINFO, PubMed, Scopus, SocINDEX, SPORTDiscus, and Web of Science.

PARTICIPANTS

NHPI children and adults, and Asian adults.

INTERVENTIONS

Proportion of NHPI meeting PAG and differences in PA involvement by sex and by ethnicity.

METHODS

Summary reporting for articles, and meta-analysis using random-effects and inverse-various weighted models.

CONCLUSIONS AND IMPLICATIONS

Just over one-third of NHPI children met the PAG (mean = 38.6%, 95% CI [32.43-45.08]), with more males (42.8%) than females (34.7%) meeting the guidelines (t = 6.74, df = 1, P = .02). Less than half met the PAG for combination (mean = 48.7%, 95% CI [34.69-62.97]), moderate (mean = 47.1%, 95% CI [33.62-61.07]), and about one-third met the PAG for vigorous PA (mean = 33.4%, 95% CI [24.55-43.62]). There were no significant differences between Asians and NHPI in PA. Policy, systems, and environmental changes as well as culturally appropriate interventions are needed to increase physical activity among NHPI.

Associations of Accumulated Time in Bouts of Sedentary Behavior and Moderate-to-Vigorous Physical Activity With Cardiometabolic Health in 10- to 13-Year-Old Boys

BACKGROUND

Little is known about the impact of sedentary and moderate-to-vigorous physical activity (MVPA) bouts on cardiometabolic health. The aim was to examine how the accumulation of bouts of sedentary time and MVPA associates to cardiometabolic health in children independently of total sedentary and MVPA time.

METHODS

In a cross-sectional study with 123 boys (10-13 y), sedentary and MVPA bouts were determined using 7-day accelerometry. Each bout was compared with cardiometabolic risk factors and with the risk score that was calculated using standardized values of body mass index, waist circumference, homeostasis model assessment for insulin resistance, triglycerides, and total cholesterol/high-density cholesterol ratio.

RESULTS

Time in 10- to 14-minute sedentary bouts was negatively associated with continuous cardiometabolic risk score in weekdays and weekend days and with triglycerides in a weekend (P < .05). Time accumulated in ≥30-minute sedentary bouts was associated with higher insulin and homeostasis model assessment for insulin resistance values in weekend (P < .05). Weekday total MVPA and time accumulated in ≥10-minute MVPA bouts were negatively associated with continuous cardiometabolic risk score and body mass index in weekdays (P < .05). No associations were found between total sedentary time and metabolic health.

CONCLUSION

Significant associations between sedentary and MVPA bouts with cardiometabolic risk factors suggest the need of the more detailed analysis for sedentary behavior and its effects on health risks.

Physical Activity and Sedentary Screen Time in Obese and Overweight Children Living in Different Environments

AIM

To assess the relationship of children's physical activity and sedentary screen time with overweight and obesity in children living in different environments (town and city) in Lithuania.

METHODS

An analysis of anthropometric data from 532 children living in town and city areas was performed. A youth physical activity questionnaire (YPAQ) was conducted to evaluate physical activity and sedentary screen time.

RESULTS

The prevalence of overweight and obesity among the children was 25.5% in the town and 18.6% in the city. Children living in the town on average engaged 9.3 min/day less in moderate to vigorous physical activity (p=0.050) and had 33.2 MET-min/day lower energy expenditure than children living in the city. Sedentary screen time was extremely high on weekends in both town and city children.

CONCLUSIONS

A higher prevalence of overweight and obesity and a lower amount of moderate-to-vigorous physical activity was found in children living in the town compared to children living in the city.

[Aerobic capacity, weight status and self-concept in schoolchildren]

OBJETIVES

To analyze the relationship between self-concept, aerobic capacity and weight status in schoolchildren.

MATERIAL AND METHOD

Relational descriptive design in which was assessed the weight status and aerobic capacity of 256 schoolchildren among 8-11 years. Aerobic capacity (low vs high) and the body mass index (normal-weight vs overweight-obesity) were categorized using standard criteria. The self-concept was assessed through the Piers Harris self-concept scale for children.

RESULTS

Schoolchildren with normal-weight and high fitness level showed better levels of conductual self-concept (P=.030), physical (P<.001), lack of anxiety (P=.048), and global self-concept (P=.002). The schoolchildren with normal-weight show higher levels of conductual self-concpt (P=.016), intellectual (P=.050), physical (P<.001), life satisfaction (P=.036), and global self-concept (P=.001). The schoolchildren with a higher fitness level showed better conductual self-concept (P=.024), physical (P=.004), lack of anxiety (P=.011), social (P=.024), and global (P=.003).

CONCLUSIONS

The results of the study strengthen the importance to transmit to the educative community the knowledge of the relationship between the variables analyzed aiming to improve the schoolchildren self-concept.

[Aerobic capacity and quality of life in school children from 8 to 12]

Aerobic capacity is a powerful physiological indicator of the overall health status. The objective of this study was to analyse the relationship between aerobic capacity and quality of life in a sample of 298 (159 girls) school children aged 8-12 years. Aerobic capacity was tested using the Course-Navette test. Quality of life was assessed using the KIDSCREEN-10 Index scale. Males showed higher performance in the Course-Navette test and highest values of VO2max (P<.001 for both). ANOVA statistical analysis showed that the quality of life was significantly higher in school children with increased level of aerobic capacity compared to those with a low level (P=.001). Children with high aerobic capacity showed higher quality of life scores in relation to their peers with low scores (P<.001). As for the females, significant differences were found among those with high aerobic capacity level and their peers low levels (P<.031). The results of this study suggest that school children with higher level of aerobic capacity show better results in the quality of life index. Long-term intervention studies are needed to verify if an aerobic capacity development programme may upgrade the quality of life of children and adolescents.

Role of physical activity in bone health in peripubertal boys

BACKGROUND

The aim of the present cross-sectional study was to investigate the relationship of physical activity level to bone mineral parameters in 11-13-year-old boys.

METHODS

In total, 264 boys, divided into normal weight (n = 154) and overweight (n = 110), participated in this study. Physical activity was measured via 7 day accelerometry and bone mineral parameters using dual-energy X-ray absorptiometry.

RESULTS

In overweight boys, vigorous physical activity was associated with total bone mineral density (BMD), total bone mineral content (BMC), while moderate-vigorous physical activity MVPA was associated with femoral neck BMD. In normal weight boys, however, only vigorous physical activity was associated with femoral neck BMD. When the normal weight group was divided into tertiles according to MVPA, femoral neck BMD was higher in the highest tertile compared to the lowest tertile. No other significant differences were found in bone mineral parameters according to the tertiles of MVPA.

CONCLUSIONS

In overweight peripubertal boys, physical activity is more associated with bone mineral parameters compared to normal weight subjects. In addition to vigorous physical activity, moderate physical activity has a significant impact on bone mineral parameters in overweight subjects.

Objective assessment of sedentary time and physical activity throughout the week in adolescents with Down syndrome. The UP&DOWN study

This study aimed to examine the patterns of sedentary time and physical activity (PA) throughout the week in adolescents with Down syndrome (DS). The study comprised 109 adolescents with DS (68 males and 41 females) aged 11-20 years, participating in the UP&DOWN study, but only a total of 100 adolescents provided valid data. Sedentary time and total, light, moderate, vigorous, and moderate-to-vigorous PA (MVPA) were measured by accelerometers. There were no significant differences in the time spent in sedentary time and PA levels between weekdays vs. weekend days, as well as between school time vs. after school-time periods (all p>0.05). Adolescent males engaged in more total PA, moderate PA, vigorous PA and MVPA than females on weekend days (all p<0.05). Differences between age groups showed that sedentary time increases and PA decreases with advancing age in all analyses, so that the oldest groups were more sedentary and less active (all p<0.05). Only 43% of adolescents with DS met the PA recommendations of ≥60min/day of MVPA. Our findings show valuable information to be considered in future interventions aiming to decrease sedentary time and increase PA levels in adolescents with DS.

A physical education trial improves adolescents' cognitive performance and academic achievement: the EDUFIT study

To analyze the effects of an intervention focused on increasing the time and intensity of Physical Education (PE), on adolescents' cognitive performance and academic achievement. A 4-month group-randomized controlled trial was conducted in 67 adolescents from South-East Spain, 2007. Three classes were randomly allocated into control group (CG), experimental group 1 (EG1) and experimental group 2 (EG2). CG received usual PE (two sessions/week), EG1 received four PE sessions/week and EG2 received four PE sessions/week of high intensity. Cognitive performance (non-verbal and verbal ability, abstract reasoning, spatial ability, verbal reasoning and numerical ability) was assessed by the Spanish Overall and Factorial Intelligence Test, and academic achievement by school grades. All the cognitive performance variables, except verbal reasoning, increased more in EG2 than in CG (all P < 0.05). Average school grades (e.g., mathematics) increased more in EG2 than in CG. Overall, EG2 improved more than EG1, without differences between EG1 and CG. Increased PE can benefit cognitive performance and academic achievement. This study contributes to the current knowledge by suggesting that the intensity of PE sessions might play a role in the positive effect of physical activity on cognition and academic success. Future studies involving larger sample sizes should confirm or contrast these preliminary findings.

Physical activity attenuates the negative effect of low birth weight on leptin levels in European adolescents; the HELENA study

We examined whether physical activity (PA) influences the association between birth weight and serum leptin in adolescents. The study comprised a total of 538 adolescents (315 girls), aged 12.5-17.49 years, born at term (≥ 37 weeks of gestation). We measured serum leptin levels and time engaged in moderate-vigorous PA (MVPA) by accelerometry. There was an interaction effect between birth weight and meeting the PA recommendations (60 min/day MVPA) on leptin levels in girls (P = 0.023) but not in boys (P = 0.809). Birth weight was negatively associated with leptin levels in girls not meeting the PA recommendations (i.e. more than 60 min/day of MVPA) (β = -0.096, P = 0.009), whereas no significant association was observed in those meeting the PA recommendations (β = -0.061, P = 0.433). In conclusion, meeting the PA recommendations may attenuate the negative effect of low birth weight on serum leptin levels in European female adolescents.

The independent associations of sedentary behaviour and physical activity on cardiorespiratory fitness

BACKGROUND

During childhood and adolescence, both physical activity (PA) and sedentary behaviour seem to influence cardiorespiratory fitness (CRF); however, the combined association of PA and sedentary behaviour remains to be understood. We analysed the combined association of objectively measured sedentary behaviour and moderate-to-vigorous intensity PA (MVPA) on CRF in Portuguese children and adolescents.

METHODS

The sample comprised 2506 Portuguese healthy children and adolescents aged 10-18 years, from a cross-sectional school-based study (2008). PA and sedentary behaviour were assessed with accelerometry. Participants were classified as meeting current PA guidelines for youth versus not meeting, and as low versus high sedentary (according to the median value of sedentary time/day by age and gender), and then grouped as follows: Low active-high sedentary; low active-low sedentary; high active-high sedentary; high active-low sedentary. CRF was assessed with the FITNESSGRAM 20 m shuttle-run test. Binary logistic regression models were constructed to verify the relationship between high CRF and the combined influence of MVPA/sedentary behaviour, adjusting for age, gender, body mass index and accelerometer wear time.

RESULTS

Participants classified as high active/low sedentary (OR=1.81; 95% CI 1.21 to 2.69), as well as those classified as low active/low sedentary (OR=1.27; 95% CI 1.01 to 1.61) were more likely to be fit, compared with those from the low-active/high-sedentary group.

CONCLUSION

MVPA and sedentary behaviour may act independently in their relation with CRF, and that MVPA levels may not overcome the deleterious influence of high-sedentary time in maximising CRF.

Recommended levels of physical activity to avoid adiposity in Spanish children

What is already known about this subject There is an association between adiposity levels and physical activity guidelines for adolescents. Achieving physical activity recommendations helps adolescents to prevent obesity status. What this study adds This paper presents an association between physical activity levels and obesity status. This paper supports physical activity recommendations to avoid children's obesity levels. This paper emphasizes vigorous physical activity for this matter.

BACKGROUND

There is no information about physical activity (PA) recommendations to avoid children's obesity levels and how much of vigorous PA (VPA) is included into the '60 minutes of MVPA 5 days a week' recommendation for children.

OBJECTIVE

The aim of this study was to examine the association between PA and adiposity in children and to examine whether the current PA guidelines are associated with a low risk of having excess of body fat in children, with special focus on sex differences, and PA intensity.

METHODS

A sample of 439 Spanish children aged 8-10 years from the European Youth Heart Study participated in the study. The variables measured were anthropometric characteristics (height, weight, body mass index [BMI], skin-folds and waist circumference) and PA was measured during 6 consecutive days using the GT1M accelerometer.

RESULTS

Receiver operating characteristic analysis showed significant cut-off points associated with non-overweight: 45 min d(-1) of VPA and 67 min d(-1) of moderate-to-vigorous physical activity (MVPA) (using BMI categories); and non-fat: 41 min d(-1) of VPA and 67 min d(-1) of MVPA (using percentage of body fat) and 38 min d(-1) of VPA and 47 min d(-1) of MVPA (using waist circumference categories) for boys. For girls, the optimal cut-offs of moderate-to-vigorous activity and MVPA associated with non-overweight were 24 and 57 min d(-1) , respectively (BMI). Boys who did not meet 67 min in MVPA had an increased risk of being overweight + obese and overfat + obese (odds ratio [OR] = 2.48, 95% confidence interval [CI] = 1.36, 4.53, and OR = 2.56, 95% CI = 1.12, 5.82).

CONCLUSIONS

The findings support current PA recommendations (60 min d(-1) of MVPA) to avoid excess of body fat in Spanish children. However, VPA appears to be an important component for the prevention of obesity, and our findings suggest that PA recommendations should specify the dose of VPA required for optimal health. Therefore, public health PA recommendations should incorporate specifically a greater dose of VPA into the total amount of MVPA in 8- to 10-year-old boys.

Associations between sedentary behavior and motor coordination in children

OBJECTIVES

This study was conducted to evaluate the relationship between objectively measured sedentary behavior (SB) and motor coordination (MC) in Portuguese children, accounting for physical activity (PA), accelerometer wear time, waist-to-height ratio, and mother's education level.

METHODS

A cross-sectional school-based study was conducted on 213 children (110 girls and 103 boys) aged 9-10 in the north of Portugal during the spring of 2010. Accelerometers were used to obtain detailed objective information about daily PA and SB over five consecutive days. MC was measured with a body coordination test (Körperkoordination Test für Kinder). Waist and height were measured by standardized protocols and the waist-to-height ratio (WHtR) was calculated. A questionnaire was used to assess mothers' educational levels. Receiver-operating characteristic (ROC) and logistic regressions were used.

RESULTS

ROC analysis showed that sedentary time significantly discriminated between children with low MC and high MC, with a best trade off between sensitivity and specificity being achieved at ≥77.29% and ≥76.48% for girls and boys, respectively (P < 0.05 for both). In both genders, the low sedentary group had significantly higher odds of having good MC than the higher sedentary group, independent of PA, accelerometer wear time, WHtR, and mother's education level (P < 0.05 for both).

CONCLUSIONS

Our findings suggested that PA levels per se may not overcome the deleterious influence of high levels of SB on MC. Our data stress the importance of discouraging SB among children to improve MC.

Bicycling to school is associated with improvements in physical fitness over a 6-year follow-up period in Swedish children

OBJECTIVE

To examine whether modes of commuting to school at baseline and changes in commuting were related to 6-year changes in cardiorespiratory fitness in youth.

METHODS

A total of 262 (142 girls) Swedish children (9 years at entry) were measured at baseline (1998/9) and follow-up (2004/5). Mode of commuting to school was assessed by questionnaire and fitness by a maximal bicycle test.

RESULTS

At baseline, 34% of children used passive modes of commuting (e.g., car, motorcycle, bus, train), 54% walked, and 12% bicycled to school. Six years later the percentage of bicyclists increased 19% and the percentage of walkers decreased 19%. On average, children who bicycled to school increased their fitness 13% (p=0.03) more than those who used passive modes and 20% (p=0.002) more than those who walked. Children who used passive modes or walked at baseline and bicycled to school at 6 years later increased their fitness 14% (p=0.001) more than those who remained using passive modes or walking at follow-up.

CONCLUSIONS

Implementing initiatives that encourage bicycling to school may be a useful strategy to increase cardiorespiratory fitness of children.

Physical activity, fitness, and serum leptin concentrations in adolescents

OBJECTIVE

To examine the association of physical activity and fitness with leptin concentrations in European adolescents, after taking into account several potential confounders including total body fat (TBF).

STUDY DESIGN

We conducted a cross-sectional study in a school setting for the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study. This study included 902 (509 girls) adolescents aged 12.5-17.5 years. Weight, height, and TBF (sum of 6 skinfold thickness) were measured, and fat free mass and body mass index were calculated. Physical activity was assessed by accelerometry. Physical fitness was assessed by the handgrip, standing long jump, 4 × 10-m shuttle run, and 20-m shuttle run tests. Serum fasting leptin, insulin, and glucose concentrations were measured, and homeostasis model assessment was computed. Multiple linear regression models were used.

RESULTS

Vigorous physical activity and fitness tests (all P < .05) were negatively associated with leptin, independently of several confounders including TBF and homeostasis model assessment. These associations remained significant after further controlling for each other (physical activity and fitness).

CONCLUSION

These results suggest that vigorous physical activity and fitness moderate the levels of leptin concentrations, regardless of relevant confounders including TBF. Intervention programs addressed to increase high intensity physical activity and fitness as well as to assess its impact on leptin concentration are required.

Volume, patterns, and types of sedentary behavior and cardio-metabolic health in children and adolescents: a cross-sectional study

BACKGROUND

Cardio-metabolic risk factors are becoming more prevalent in children and adolescents. A lack of moderate-to-vigorous intensity physical activity (MVPA) is an established determinant of cardio-metabolic risk factors in children and adolescents. Less is known about the relationship between sedentary behavior and cardio-metabolic health. Therefore, the objective was to examine the independent associations between volume, patterns, and types of sedentary behavior with cardio-metabolic risk factors among children and adolescents.

METHODS

The results are based on 2527 children and adolescents (6-19 years old) from the 2003/04 and 2005/06 National Health and Nutrition Examination Surveys (NHANES). A cardio-metabolic risk score (CRS) was calculated based on age- and sex-adjusted waist circumference, systolic blood pressure, non-high-density lipoprotein cholesterol, and C-reactive protein values. Volume and patterns of sedentary behavior and moderate-to-vigorous physical activity (MVPA) were measured objectively using accelerometers. Types of sedentary behavior were measured by questionnaire. A series of logistic regression models were used to examine associations.

RESULTS

Volume and patterns of sedentary behavior were not predictors of high CRS after adjusting for MVPA and other confounders (P > 0.1). For types of sedentary behavior, high TV use, but not high computer use, was a predictor of high CRS after adjustment for MVPA and other confounders. Children and adolescents who watched ≥4 hours per day of TV were 2.53 (95% confidence interval: 1.45-4.42) times more likely to have high CRS than those who watched <1 hour per day. MVPA predicted high CRS after adjusting for all sedentary behavior measures and other confounders. After adjustment for waist circumference, MVPA also predicted high non-obesity CRS; however, the same relationship was not seen with TV use.

CONCLUSION

No association was observed between overall volume and patterns of sedentary behavior with cardio-metabolic risk factors in this large sample of children and adolescents. Conversely, high TV use and low MVPA were independently associated with cardio-metabolic risk factors. However, the association between high TV use and clustered cardio-metabolic risk factors appears to be mediated or confounded by obesity. Thus, TV and MVPA appear to be two separate behaviors that need to be targeted with different interventions and policies.

Etiology, Treatment and Prevention of Obesity in Childhood and Adolescence: A Decade in Review

Childhood obesity has become an epidemic on a worldwide scale. This article gives an overview of the progress made in childhood and adolescent obesity research in the last decade, with a particular emphasis on the transdisciplinary and complex nature of the problem. The following topics are addressed: 1) current definitions of childhood and adolescent overweight and obesity; 2) demography of childhood and adolescent obesity both in the US and globally; 3) current topics in the physiology of fat and obesity; 4) psychosocial correlates of childhood and adolescent overweight and obesity; 5) the three major obesity-related behaviors, i.e. dietary intake, physical activity and sleep; 6) genes components of childhood and adolescent obesity; 7) environment and childhood and adolescent obesity; and 8) progress in interventions to prevent and treat childhood obesity. The article concludes with recommendations for future research, including the need for large-scale, high dose and long-term interventions that take into account the complex nature of the problem.