Metabolic risk factors, physical activity and physical fitness in Azorean adolescents: a cross-sectional study

Metabolic syndrome and its association with physical activity in Sudanese early adolescents - Khartoum state, Sudan: An observational study

The growing prevalence of overweight/obesity in adolescents highlights the significance of studying metabolic syndrome (MetS) in increasingly sedentary adolescents. To date, no study in Sudan has examined the association between MetS and physical activity (PA) among adolescents. This study aimed to assess the association between MetS and its components and PA among Sudanese early adolescents. A cross-sectional assessment was conducted from to 2018 to 2019 on a sample of 921 primary school students from Khartoum State, Republic of Sudan. MetS was defined according to the International Diabetes Federation criteria and a standardized questionnaire was used to assess PA. Metabolic equivalents of task were calculated, and levels of different intensities of PA (tertiles) were identified accordingly. The association between PA and MetS and its components was assessed using a logistic regression model. The participants comprised 388 boys and 533 girls with a mean age of 12.59 ± 1.21 years. The prevalence of MetS was significantly higher in subjects in the 1st PA tertile (least active) than in the 2nd and 3rd (most active) tertiles of PA, and this difference was observed in both boys and girls. After adjusting for other study factors, the odds of MetS among adolescents in the 1st PA tertile were 7 times higher than those in the highest PA tertile (adjusted odds ratio = 7.01, 95% confidence interval: 1.48, 32.99). A physically inactive lifestyle was associated with higher odds of MetS and its components, especially waist circumference and triglyceride levels, in Sudanese early adolescents. This study highlights the importance of promoting PA in this age group.

Which anthropometric equation to predict body fat percentage is more strongly associated with maximum oxygen uptake in adolescents? A cross-sectional study

BACKGROUND

Identifying the relationship between maximum consumption of oxygen and body fat percentage is important due to increased cardiovascular risk factors.

OBJECTIVE

This study aimed to verify the association between body fat percentage determined by three predictive equations using anthropometric measures (Lohman, Boileau, and Slaughter) and maximum oxygen uptake (VO2max). We also aimed to estimate the capacity of these equations for explaining VO2max variations in adolescents according to sex.

DESIGN AND SETTING

This was a cross-sectional study conducted in high schools in São José, Southern Brazil.

METHODS

This study included 879 adolescents (14-19 years) from Southern Brazil. Aerobic fitness was assessed using the modified Canadian Aerobic Fitness Test. The independent variable was body fat percentage predicted by the Lohman, Boileau, and Slaughter equations. Analyses adjusted for sociodemographic variables, physical activity level, and sexual maturation were performed with P value < 0.05.

RESULTS

All anthropometric prediction equations used to estimate body fat percentage explained VO2max variations in adolescents. In male adolescents, both regression models based on the Boileau et al.12 and Lohman10 equations revealed higher explanatory power for VO2max (20%) compared with that based on the Slaughter et al.13 equation (19%). In female adolescents, the model based on the anthropometric equation of Slaughter et al.13 showed the greatest explanatory power for VO2max (18%).

CONCLUSION

The inverse relationship between VO2max and body fat intensifies the need for effective intervention programs that prioritize maintenance of appropriate body fat and aerobic fitness levels because inadequate levels of both factors result in negative health consequences.

Relationship between Moderate-to-Vigorous Physical Activity with Health-Related Physical Fitness Indicators among Pakistani School Adolescents: Yaali-Pak Study

Background

The current study is the foremost study exploring the relationships between moderate-to-vigorous physical activity and health-related physical fitness indicators among 12-16-year-old adolescents of the South Punjab region of Pakistan.

Methods

The researcher adopted the cross-sectional research design for the study. A total of 2970 participants (1477 boys and 1493 girls) aged adolescents from South Punjab, Pakistan, completed health-related physical fitness indicators measuring strength, endurance, and aerobic capacity through a hand-grip strength test, modified pull-up test, plank test, and 20-m shuttle run test, and physical activity were subjectively assessed by International Physical Activity Questionnaire Short Form (IPAQ-SF). Linear regression models were used to explore the between moderate-to-vigorous physical activity (MVPA) with health-related physical fitness indicators.

Results

Positive associations were observed between hand-grip strength (p < 0.001), modified pull-up (p < 0.001), plank exercise (p < 0.001), and 20-m shuttle run test (p < 0.001), with MVPA. The gender-specific comparison also indicated a significant (p < 0.001) and positive relationship. The results revealed that as MVPA increases, body composition, muscular strength, core muscular endurance, and aerobic capacity could improve in both genders.

Conclusions

MVPA appears to be an effective and reliable predictor of health-related physical fitness among school adolescents.

OXYGEN UPTAKE AND INDICATORS OF OBESITY: META-ANALYSIS INCLUDING 17,604 ADOLESCENTS

ABSTRACT Introduction: Low aerobic fitness levels are associated with excess body adiposity in adolescents. However, studies that have analyzed this association in adolescents have used different methods and measures to evaluate aerobic fitness, making it difficult to compare the results. Objective: To conduct a systematic review with meta-analysis of studies that have analyzed the association between aerobic fitness and anthropometric body adiposity indicators in adolescents aged 10-19 years. Methods: A systematic search was performed in May 2016, updated in March 2017, in the following electronic databases: LILACS (BIREME), Embase, MEDLINE (PubMed), Web of Science (Web of Knowledge), Scopus, and SPORTDiscus. Results: Twenty-three studies were selected. The meta-analysis indicated that as the aerobic fitness levels increased, the BMI, waist circumference and body fat percentage values of the adolescents decreased. Conclusion: There is a negative association between aerobic fitness (evaluated by measuring maximum oxygen uptake in the 20-meter Shuttle Run test) and the body fat percentage, BMI and waist circumference of adolescents and a negative association between aerobic fitness (assessed by measuring the number of laps in the 20-meter Shuttle Run test) and body fat percentage. However, caution is required in the interpretation of data due to the heterogeneity of the studies analyzed. Level of Evidence II; Systematic review of studies with level II of evidence.

Improving Physical Fitness of Children with Intellectual and Developmental Disabilities through an Adapted Rhythmic Gymnastics Program in China

Background

Health-related physical fitness is vital for children with intellectual and developmental disabilities (IDD) to gain healthier lives. The adapted rhythmic gymnastics (ARG) program was designed for children with IDD and is aimed at testing the effects of the exercise program on children's physical fitness.

Methods

Participants were recruited from two special needs schools in Beijing of China. Twenty-two children with IDD were assigned to an ARG experimental group or a traditional control group. The experimental group took part in a 16-week ARG program consisting of three 50 min sessions each week. And children's body composition, aerobic capacity, and musculoskeletal functioning were measured by the Brockport Physical Fitness Test (BPFT) before and after the program.

Results

The between-group analysis revealed great improvements for the experimental group in abdominal strength (curl-up test: p = 0.025 < 0.05) and upper limb strength (dumbbell press test: p = 0.038 < 0.05). Compared to the pretest, most of the physical fitness parameters improved significantly in the experimental group except BMI, and flexibility of the experimental group children showed a substantial increase.

Conclusions

Most of the physical fitness parameters of children with IDD in the experimental group improved significantly, especially on abdominal strength and upper limb muscle strength when comparing to the control group.

COMPARISON OF DIFFERENT CRITERIA IN THE PREVALENCE OF METABOLIC SYNDROME IN STUDENTS FROM PARANAVAÍ, PARANÁ

Objective:

To investigate the difference in the proportion of students with metabolic syndrome, diagnosed according to different criteria.

Methods:

The sample consisted of 241 students (136 boys and 105 girls) aged 10 to 14 years, from public and private schools in Paranavaí, Paraná. We used three distinct diagnostic criteria for metabolic syndrome, considering the presence of at least three of the following risk factors: increased waist circumference, hypertension, fasting hyperglycemia, low HDL-C, and elevated triglycerides.

Results:

The prevalence of metabolic syndrome found was 1.7% (confidence interval of 95% - 95%CI 0-3.3) for the IDF criterion; 3.3% (95%CI 1.0-5.6) for Cook; and 17.4% (95%CI 12.6-22.3) for Ferranti. Analyzing the criteria in pairs, the agreement between IDF and Cook was 97.5% (k=0.95); between IDF and Ferranti, 83.4% (k=0.67); and between Cook and Ferranti, 85.9% (k=0.72). Onlyone student (0.4%) was diagnosed with metabolic syndrome solely by the IDF criterion, while 34 (14.1%) were diagnosed exclusively by Ferranti. The comparison of the three criteria showed that Ferranti presented the highest proportion of metabolic syndrome (p<0.001), and Cook had a greater proportion than IDF (p<0.001).

Conclusions:

We found a significant difference in the proportion of metabolic syndrome in the three criteria. The choice of which criterion to use can compromise not only the percentage of metabolic syndrome prevalence but also interfere in strategies of intervention and prevention in children and adolescents with and without metabolic syndrome, respectively.

School-Based Intervention on Cardiorespiratory Fitness in Brazilian Students: A Nonrandomized Controlled Trial

BACKGROUND

In response to the worldwide increasing prevalence of low cardiorespiratory fitness (CRF), several interventions have been developed. The aim of this study was to examine the effect of a school-based intervention on CRF in Brazilian students.

METHODS

A nonrandomised controlled design tested 432 students (intervention group: n = 247) from 6th to 9th grade recruited from two public secondary schools in Florianopolis, in 2015. The intervention entitled "MEXA-SE" (move yourself), applied over 13 weeks, included four components: (1) increases in physical activity during Physical Education classes; (2) active recess; (3) educational sessions; and (4) educational materials. CRF (20-m shuttle run test) was the primary outcome.

RESULTS

The effect size of the intervention on CRF was 0.15 (CI 95% = -0.04; 0.34). In the within-group comparisons, VO2max decreased significantly from baseline to follow-up in the control group but remained constant in the intervention group. After adjustment variables, differences between intervention and control group were not statistically significant (p > 0.05).

CONCLUSION

The "MEXA-SE" intervention did not have an effect on adolescents' CRF. However, maintenance of VO2max in intervention group and a reduction within control group demonstrates that this intervention may be beneficial for long-term CRF and, possibly, the increased intervention time could result in a better effect.

Statistical methods to model and evaluate physical activity programs, using step counts: A systematic review

Background

Physical activity reduces the risk of noncommunicable diseases and is therefore an essential component of a healthy lifestyle. Regular engagement in physical activity can produce immediate and long term health benefits. However, physical activity levels are not as high as might be expected. For example, according to the global World Health Organization (WHO) 2017 statistics, more than 80% of the world’s adolescents are insufficiently physically active. In response to this problem, physical activity programs have become popular, with step counts commonly used to measure program performance. Analysing step count data and the statistical modeling of this data is therefore important for evaluating individual and program performance. This study reviews the statistical methods that are used to model and evaluate physical activity programs, using step counts.

Methods

Adhering to PRISMA guidelines, this review systematically searched for relevant journal articles which were published between January 2000 and August 2017 in any of three databases (PubMed, PsycINFO and Web of Science). Only the journal articles which used a statistical model in analysing step counts for a healthy sample of participants, enrolled in an intervention involving physical exercise or a physical activity program, were included in this study. In these programs the activities considered were natural elements of everyday life rather than special activity interventions.

Results

This systematic review was able to identify 78 unique articles describing statistical models for analysing step counts obtained through physical activity programs. General linear models and generalized linear models were the most popular methods used followed by multilevel models, while structural equation modeling was only used for measuring the personal and psychological factors related to step counts. Surprisingly no use was made of time series analysis for analysing step count data. The review also suggested several strategies for the personalisation of physical activity programs.

Conclusions

Overall, it appears that the physical activity levels of people involved in such programs vary across individuals depending on psychosocial, demographic, weather and climatic factors. Statistical models can provide a better understanding of the impact of these factors, allowing for the provision of more personalised physical activity programs, which are expected to produce better immediate and long-term outcomes for participants. It is hoped that this review will identify the statistical methods which are most suitable for this purpose.

Associations of Anthropometric Characteristics, Dietary Habits, and Aerobic Capacity With Cardiovascular Risk Factors of Health-Science Students

The aim of this cross-sectional study was to study the relative importance of dietary habits and aerobic capacity in parameters related to cardiovascular risk in 271 female and 95 male health-science students (mean age = 19.1 ± 1.4 years). In females, fatty-meat consumption predicted triglycerides (β = .649, p < .001) and high-density lipoprotein (HDL; β = -.242, p = .001) and low-density lipoprotein (LDL; β = .373, p < .001) cholesterol levels. Consumption of nuts, legumes, and complex carbohydrates predicted triglyceride (β = -.099, p = .074), HDL (β = .231, p = .001), and LDL (β = -.155, p = .025) levels, respectively. Aerobic capacity (β = -.245, p < .001) and fatty-meat intake (β = .230, p < .001) predicted diastolic blood pressure (BP); body mass index (BMI) predicted systolic BP (β = .340, p < .001). In males, body fat percentage was the strongest predictor of triglycerides (β = .348, p = .004), cholesterol (β = .366, p = .006), HDL (β = -.378, p = .004), and LDL (β = .271, p = .043) levels. Aerobic capacity (β = -.263, p = .013) and fatty-meat consumption (β = .334, p = .005) independently predicted triglyceride levels. Nut (β = -.286, p = .013) and fatty-meat intake (β = .361, p = .002) predicted systolic BP, while BMI predicted diastolic BP (β = .209, p = .045). As health sciences students, these participants are future health professionals; targeting such populations is important for chronic disease prevention.

Associations between self-reported fitness and self-rated health, life-satisfaction and health-related quality of life among adolescents

Background/objective

In recent years, there has been an increased interest in the associations between physical fitness (PF) and psychosocial aspects of health. This study aimed to analyse the associations between self-reported PF and self-rated health (SRH), life-satisfaction (LS), and quality of life (QoL).

Methods

This is a cross-sectional study of 3554 adolescents (1652 boys), aged 13–18, from the HBSC Portuguese survey. PF, health, LS and OoL were self-rated.

Results

SRH, LS, and health-related OoL (HRQoL) were significantly and positively correlated with all PF components. From regression model, overall fitness was significantly related with SRH (boys: β = 0.18, p < 0.001; girls: β = 0.16, p < 0.001), LS (boys: β = 0.36, p < 0.001; girls: β = 0.43, p < 0.001), and HRQoL (boys: β = 2.26, p < 0.001; girls: β = 2.54, p < 0.001). Cardiorespiratory fitness was also positively and significantly related with SRH (boys: β = 0.17, p < 0.001; girls: β = 0.11, p < 0.001), LS (boys: β = 0.13, p < 0.05; girls: β = 0.31, p < 0.001), and HRQoL (boys: β = 1.74, p < 0.001; girls: β = 1.57, p < 0.001).

Conclusion

These findings suggest that perceived PF is associated with a better SRH, LS, and perceived HRQoL. A few implications regarding public policies were highlighted.

Systematic review of the relationships between objectively measured physical activity and health indicators in school-aged children and youth

Moderate-to-vigorous physical activity (MVPA) is essential for disease prevention and health promotion. Emerging evidence suggests other intensities of physical activity (PA), including light-intensity activity (LPA), may also be important, but there has been no rigorous evaluation of the evidence. The purpose of this systematic review was to examine the relationships between objectively measured PA (total and all intensities) and health indicators in school-aged children and youth. Online databases were searched for peer-reviewed studies that met the a priori inclusion criteria: population (apparently healthy, aged 5-17 years), intervention/exposure/comparator (volumes, durations, frequencies, intensities, and patterns of objectively measured PA), and outcome (body composition, cardiometabolic biomarkers, physical fitness, behavioural conduct/pro-social behaviour, cognition/academic achievement, quality of life/well-being, harms, bone health, motor skill development, psychological distress, self-esteem). Heterogeneity among studies precluded meta-analyses; narrative synthesis was conducted. A total of 162 studies were included (204 171 participants from 31 countries). Overall, total PA was favourably associated with physical, psychological/social, and cognitive health indicators. Relationships were more consistent and robust for higher (e.g., MVPA) versus lower (e.g., LPA) intensity PA. All patterns of activity (sporadic, bouts, continuous) provided benefit. LPA was favourably associated with cardiometabolic biomarkers; data were scarce for other outcomes. These findings continue to support the importance of at least 60 min/day of MVPA for disease prevention and health promotion in children and youth, but also highlight the potential benefits of LPA and total PA. All intensities of PA should be considered in future work aimed at better elucidating the health benefits of PA in children and youth.

Association between cardiorespiratory fitness and body fat in girls

OBJECTIVE

To estimate the prevalence of low cardiorespiratory fitness and its association with excess body fat, considering the sexual maturation and economic level in female adolescents.

METHODS

Cross-sectional, epidemiological study of 1,223 adolescents (10-17 years) from the public school system of Cascavel, PR, Brazil, in 2006. We analyzed the self-assessed sexual maturation level (prepubertal, pubertal and post-pubertal), the Economic Level (EL) (high and low) through a questionnaire and body fat (normal and high) through triceps and subscapular skinfolds. The 20-meter back-and-forth test was applied to estimate maximum oxygen consumption. Cardiorespiratory fitness was assessed according to reference criteria and considered low when the minimum health criterion for age and sex was not met. Chi-square test and logistic regression were applied, with a significance level of 5%.

RESULTS

The prevalence of low cardiorespiratory fitness was 51.3%, being associated with all study variables (p<0.001). At the crude analysis, adolescents with high body fat were associated with low cardiorespiratory fitness, when compared to those with normal body fat (OR=2.76; 95%CI: 2.17-3.52). After adjustment by sexual maturation, this association remained valid and showed an effect that was 1.8-fold higher (95%CI: 1.39-2.46) and after adjusting by EL, the effect was 1.9-fold higher (95%CI: 1.45-2.61).

CONCLUSIONS

Approximately half of the assessed girls showed unsatisfactory levels of cardiorespiratory fitness for health, which was associated with high body fat, regardless of sexual maturation level and EL. Effective public health measures are needed, with particular attention to high-risk groups.

Association between cardiorespiratory fitness and body fat in girls

Objective:

To estimate the prevalence of low cardiorespiratory fitness and its association with excess body fat, considering the sexual maturation and economic level in female adolescents.

Methods:

Cross-sectional, epidemiological study of 1223 adolescents (10-17 years) from the public school system of Cascavel, PR, Brazil, in 2006. We analyzed the self-assessed sexual maturation level (prepubertal, pubertal and post-pubertal), the economic level (high and low) through a questionnaire and body fat (normal and high) through triceps and subscapular skinfolds. The 20-meter back-and-forth test was applied to estimate maximum oxygen consumption. Cardiorespiratory fitness was assessed according to reference criteria and considered low when the minimum health criterion for age and sex was not met. Chi-square test and logistic regression were applied, with a significance level of 5%.

Results:

The prevalence of low cardiorespiratory fitness was 51.3%, being associated with all study variables (p<0.001). At the crude analysis, adolescents with high body fat were associated with low cardiorespiratory fitness, when compared to those with normal body fat (OR=2.76; 95%CI: 2.17-3.52). After adjustment by sexual maturation, this association remained valid and showed an effect that was 1.8-fold higher (95%CI: 1.39-2.46) and after adjusting by economic level, the effect was 1.9-fold higher (95%CI: 1.45-2.61).

Conclusions:

Approximately half of the assessed girls showed unsatisfactory levels of cardiorespiratory fitness for health, which was associated with high body fat, regardless of sexual maturation level and economic level. Effective public health measures are needed, with particular attention to high-risk groups.

Cardiorespiratory fitness is related to metabolic risk independent of physical activity in boys but not girls from Southern Brazil

OBJECTIVE

Our aim was to determine the relationship between cardiorespiratory fitness (CRF) and metabolic risk in adolescents from Southern Brazil.

METHODS

We performed a school-based cross-sectional study in 1,037 adolescents (436 boys) aged 10-16 years from Londrina, PR, Brazil. CRF was determined by 20-m shuttle run test. A continuous metabolic risk score was obtained from the mean of fasting glucose, triglycerides, high density lipoprotein, blood pressure, and waist circumference z-scores. Age, physical activity (Baecke questionnaire), body mass index (BMI; weight/stature(2) ), and somatic maturity (Mirwald method) were included as covariates in multiple linear regression analyses.

RESULTS

CRF was related to metabolic risk in boys (β = -0.02, P < 0.01) and girls (β = -0.01, P = 0.02) after adjusting for chronological age, BMI, and somatic maturity. However, when adjusted for physical activity, CRF failed to explain metabolic risk in girls (β = -0.01, P = 0.24).

CONCLUSION

We conclude that CRF is independently and inversely related to metabolic risk in boys, but physical activity either mediates or confounds the association between CRF and metabolic risk in girls. Am. J. Hum. Biol. 28:534-538, 2016. © 2016 Wiley Periodicals, Inc.

Modeling longitudinal changes in hypertensive and waist phenotype: The oporto growth, health, and performance study

OBJECTIVES

This study aimed to: (1) model changes in the hypertensive and waist phenotype (HWP) in youth, and (2) investigate the effects of sex, biological maturation, total physical activity (TPA), and physical fitness (PF) in HWP trajectories.

METHODS

Data were obtained annually for 3 years from the Oporto Growth, Health, and Performance Study, and comprised 5,549 adolescents (2,732 girls) divided into four age cohorts (10, 12, 14, and 16 years). The HWP was computed as the sum of the standardized score of waist circumference and mean arterial pressure. Biological maturation was indirectly assessed by the maturity offset procedure; TPA was estimated with the Baecke questionnaire; PF measures included 1-mile run/walk, 50-yard dash (50YD), standing long jump (SLJ), handgrip strength (HGr), and agility shuttle run. Longitudinal changes in HWP were analyzed using multilevel modelling.

RESULTS

HWP increased across time with a nonlinear trend in girls and boys. However, when adjusted for a set of predictors, the trend was reversed: girls and boys had a significant annual decrease on HWP of -0.202 ± 0.032 and -0.147 ± 0.032, respectively. Maturity offset was positively associated with HWP changes (β = 0.913 ± 0.023); TPA had a negative association (β = -0.027 ± 0.011); and improved PF tests were associated with a significant reduction in HWP across time (β1mile  = -0.081 ± 0.009; βSLJ  = -0.003 ± 0.00; β50YD =0.106 ± 0.020; and βHGr  = -3.335 ± 0.196).

CONCLUSIONS

Boys showed higher HWP values compared to girls from 10 to 18 years of age. Adolescents who were more biologically mature had a more adverse HWP. Longitudinal increases in TPA and PF predicted annual decreases in HWP across the adolescence years.Am. J. Hum. Biol. 28:387-393, 2016. © 2015 Wiley Periodicals, Inc.

Association between physical activity, sedentary time, and healthy fitness in youth

PURPOSE

This study aimed to examine the associations between objectively measured physical activity (PA), sedentary time, and health-related fitness and to investigate the combined association of PA and sedentary time on health-related fitness in youths.

METHODS

PA and sedentary time were assessed with accelerometers in 2506 youths age 10-18 yr (M(age) = 13.2 ± 2.3). Participants were classified as active (≥60 min·d(-1) of moderate-to-vigorous physical activity (MVPA)) versus inactive (<60 min·d(-1) of MVPA) and as "low sedentary" versus "high sedentary" (according to the median value of sedentary time per day) and thereafter grouped as active/low sedentary, active/high sedentary, inactive/low sedentary, and inactive/high sedentary. Five physical fitness tests (body mass index, push-ups, curl-ups, sit and reach, and the Progressive Aerobic Cardiovascular Endurance Run test) were assessed with FITNESSGRAM, and participants were categorized as being in the healthy fitness zone (HFZ) versus the unhealthy fitness zone. A fitness composite score was calculated using the individual fitness test z-score. Regression models were used to examine the relation between PA, sedentary time, and physical fitness.

RESULTS

Time spent in MVPA (min·d(-1)) (β = 0.002, P < 0.001) was significantly associated with fitness score independent of sedentary time. Sedentary time was not associated with physical fitness independent of MVPA. Compared with the inactive/high sedentary group (referent), being categorized as active/low sedentary was associated with increased likelihood of being in the HFZ for sit and reach (odds ratio, 2.55; 95% confidence interval, 1.96-3.32) and having a higher fitness composite score (odds ratio, 1.38; 95% confidence interval, 1.13-1.69).

CONCLUSIONS

Time in MVPA was associated with better physical fitness independent of sedentary time. Participants classified as active/low sedentary had higher odds of being in the HFZ, for flexibility, and to have a better fitness composite score. These findings suggest that time in MVPA contributes to better physical fitness in youths.

Development of physical fitness in children with intellectual disabilities

BACKGROUND

Few studies examined the development of physical fitness in children and youth with intellectual disabilities (ID), but the developmental patterns of physical fitness are largely unknown. The first aim was to examine physical fitness of primary school children with ID, aged 8-12, and compare the results with typically developing children in order to determine the performance level of children with ID. The second aim was to investigate the developmental trajectory of physical fitness in children with ID and the possible influence of gender and severity of cognitive impairment in a 4-year during longitudinal study.

METHOD

Seventy-three children with borderline or mild ID (51 boys, 22 girls; age range 8-11 in the year of enrolment) were measured annually on running speed, aerobic endurance (cardiovascular endurance), explosive strength, handgrip strength and trunk strength. Physical fitness scores of 515 typically developing children (266 boys, 249 girls; age range 8-12) were collected for reference values.

RESULTS

The results indicated statistically significant differences (with moderate to large Effect Sizes) between children with ID and typically developing children in all ages, favouring the typically developing children, and showed that the gap remained stable across the ages or decreased with increasing age. Multilevel models showed that the children with ID developed statistically significant on all items of physical fitness between age 8 and age 12. There was no statistically significant effect of gender on physical fitness, and the developmental trajectories were similar for boys and girls. For children with borderline and mild ID the developmental trajectories were parallel, but children with mild ID scored statistically significant worse on running speed, explosive strength and handgrip strength.

CONCLUSIONS

Despite statistically significant development of physical fitness in children with ID, their physical fitness levels should be stimulated. This should start already in young children (<8 years) and the children with the most severe cognitive impairments need special attention.

The combined effect of physical activity and sedentary behaviors on a clustered cardio-metabolic risk score: The Helena study

BACKGROUND/OBJECTIVE

Increased physical activity (PA) and decreased sedentary behaviors (SBs) may have beneficial effects on cardio-metabolic risk in adolescents. The aim of this study was to examine the associations between independent/combined effects of PA and SB with individual/clustered cardio-metabolic risk factors.

METHODS

A sample of 769 adolescents (12.5-17.5 years) from the HELENA cross-sectional study (Healthy Lifestyle in Europe by Nutrition in Adolescence) and with valid data on metabolic risk factors were included.

RESULTS

Concerning moderate-to-vigorous-PA (MVPA) and vigorous-PA (VPA), measured with accelerometers, girls tended to do more MVPA (36%) and VPA (114%) than boys. Unadjusted analyses show a positive association between "PA ≥ 60 min/d; SB ≥ 2 h" and the ratio TC/HDL-c (β = 0.27; 95%CI 0.01 to 0.52; p < 0.05), and a negative association between "MVPA ≥ 60 min/d; SB < 2h" with the ∑ 4Skinfolds (β = -0.32; 95%CI -0.61 to -0.02; p<0.05). Moreover, "SB ≥ 2 h/d" was associated with increased cardio-metabolic risk (PR 1.59; 95%CI 1.05 to 2.39; p < 0.05), while "PA ≥ 60 min/d; SB < 2h" had a protective effect against cardio-metabolic risk (PR 0.48; 95%CI 0.25 to 0.91; p < 0.05). After adjustment for potential confounders, a positive association between SB and ∑ 4Skinfolds was shown (β = 0.28; 95%CI 0.04 to 0.53; p < 0.05). Furthermore, VO2max (mL/kg/min) tends to increase in those participants who do higher VPA and less SB (p = 0.042), and there was a protective effect of "VPA ≥ 30 min/d; SB < 2h" against cardio-metabolic risk (PR 0.24; 95%CI 0.07 to 0.85; p < 0.05).

CONCLUSION

The current study suggests that adolescents should be encouraged to decrease sedentary lifestyle and increase physical activity, especially vigorous physical activity, in order to reduce cardio-metabolic risk.

Independent association of clustered metabolic risk factors with cardiorespiratory fitness in youth aged 11-17 years

BACKGROUND

Although the prevalence of metabolic syndrome (MetS) has increased in youth, the potential independent contribution of cardiorespiratory fitness (CRF) to the clustering of metabolic risk factors has received relatively little attention.

AIM

This study evaluated associations between the clustering of metabolic risk factors and CRF in a sample of youth.

SUBJECTS AND METHODS

Height, weight, BMI, fasting glucose, insulin, HDL-cholesterol, triglycerides and blood pressures were measured in a cross-sectional sample of 924 youth (402 males, 522 females) of 11-17 years. CRF was assessed using the 20-metre shuttle run test. Physical activity (PA) was measured with a 3-day diary. Outcome variables were statistically normalized and expressed as Z-scores. A MetS risk score was computed as the mean of the Z-scores. Multiple linear regression was used to test associations between CRF and metabolic risk, adjusted for age, sex, BMI, PA and parental education.

RESULTS

CRF was inversely associated with MetS after adjustment for potential confounders. After adjusting for BMI, the relationship between CRF and metabolic risk has substantially improved.

CONCLUSION

CRF was independently associated with the clustering of metabolic risk factors in youth of 11-17 years of age.

Aptidão cardiorrespiratória, indicadores sociodemográficos e estado nutricional em adolescentes

INTRODUÇÃO: níveis inadequados de aptidão cardiorrespiratória na adolescência estão inversamente associados a fatores de risco cardiovasculares e metabólicos.OBJETIVO: verificar a associação da aptidão cardiorrespiratória com indicadores sociodemográficos e o estado nutricional em adolescentes.MÉTODOS: estudo transversal realizado em 627 adolescentes (361 moças), com idades de 14 a 17 anos, de ambos os sexos em uma cidade de médio/baixo Índice de Desenvolvimento Humano (IDH). Foram coletadas as variáveis antropométricas (massa corporal - MC e estatura - EST) para a obtenção do índice de massa corporal (IMC=MCkg/ESTm2) e as informações sociodemográficas (idade, nível econômico e área de domicílio). Para análise da aptidão cardiorrespiratória baixa (teste correr/caminhar 1.600 metros), considerou-se o tempo de realização do teste igual ou superior a 7:45 minutos (min) e 7:30 min para os rapazes de 14 e de 15 a 17 anos, respectivamente, e o tempo de 10:30 min para as moças.RESULTADOS: a aptidão cardiorrespiratória baixa foi verificada em 35,3% dos rapazes e 35,5% das moças. Os rapazes pertencentes aos estratos econômicos menos favorecidos (Classe C: RP=0,54; IC95%=0,31-0,93; Classe: D+E: RP=0,46; IC95%=0,22-0,98) estiveram menos expostos a baixos níveis de aptidão cardiorrespiratória. Por outro lado, os rapazes que nasceram com baixo peso (RP=1,49; IC95%=1,04-2,13) e os rapazes e as moças residentes na área urbana (rapazes: RP=1,79; IC95%=1,28-2,50; moças: RP=1,32; IC95%=0,99-1,75) apresentaram maiores probabilidades de terem baixa aptidão cardiorrespiratória.CONCLUSÃO: os indicadores que apresentaram associação com a aptidão cardiorrespiratória baixa para os rapazes foram área de domicílio urbana e nível econômico intermediário e baixo. Para as moças, o resultado associou-se somente com a área de domicílio. Sugerem-se intervenções para a promoção da saúde voltadas principalmente para os adolescentes residentes na área urbana e pertencentes aos estratos econômicos mais abastados.

Relation between usual daily walking time and metabolic syndrome

BACKGROUND

There are several studies about the positive relation between physical inactivity or low cardio respiratory fitness with development of metabolic syndrome (MS). In contrast, physical activity had favourable effects on all components of MS but the quantity and the frequency of physical activity necessary to produce this beneficial effect has not been defined as yet. The aim of this survey was to study the association of regular physical activity, measured by patient's estimation of walking time per day, with MS.

MATERIALS AND METHODS

This cross-sectional study was conducted as a part of Isfahan Healthy Heart Program (IHHP). Persons who had no component of MS were considered as reference group. Demographic data were collected by questionnaire. Relation between walking time and MS was evaluated by using logistic regression adjusted by age, sex, socioeconomic status (SES), life style and food item.

RESULTS

The study populations consisted of 4151 persons. Lower physical activity was associated with higher prevalence of MS (P < 0.001). There was a negative relation between the usual daily walking time and MS. Adjusted odds ratio for age groups, sex, SES, life style and food items (fat and oil, sweet and sweet drink, rice and bread, fried food) revealed that MS decreases with increasing walking time (P < 0.05) [OR = 0.70 (0.52-0.94)].

CONCLUSION

Total daily walking time is negatively associated with MS and increasing daily walking time is an effective way for preventing MS.

Physical fitness among urban and rural Ecuadorian adolescents and its association with blood lipids: a cross sectional study

BACKGROUND

Physical fitness has been proposed as a marker for health during adolescence. Currently, little is known about physical fitness and its association with blood lipid profile in adolescents from low and middle-income countries. The aim of this study is therefore to assess physical fitness among urban and rural adolescents and its associations with blood lipid profile in a middle-income country.

METHODS

A cross-sectional study was conducted between January 2008 and April 2009 in 648 Ecuadorian adolescents (52.3% boys), aged 11 to 15 years, attending secondary schools in Cuenca (urban n = 490) and Nabón (rural n = 158). Data collection included anthropometric measures, application of the EUROFIT battery, dietary intake (2-day 24 h recall), socio-demographic characteristics, and blood samples from a subsample (n = 301). The FITNESGRAM standards were used to evaluate fitness. The associations of fitness and residential location with blood lipid profile were assessed by linear and logistic regression after adjusting for confounding factors.

RESULTS

The majority (59%) of the adolescents exhibited low levels of aerobic capacity as defined by the FITNESSGRAM standards. Urban adolescents had significantly higher mean scores in five EUROFIT tests (20 m shuttle, speed shuttle run, plate tapping, sit-up and vertical jump) and significantly most favorable improved plasma lipid profile (triglycerides and HDL) as compared to rural adolescents. There was a weak association between blood lipid profile and physical fitness in both urban and rural adolescents, even after adjustment for confounding factors.

CONCLUSIONS

Physical fitness, in our sample of Ecuadorian adolescents, was generally poor. Urban adolescents had better physical fitness and blood lipid profiles than rural adolescents. The differences in fitness did not explain those in blood lipid profile between urban and rural adolescents.

Supplementary use of HbA1c as hyperglycemic criterion to detect metabolic syndrome

BACKGROUND

Metabolic syndrome (MetS) refers to a cluster of cardiovascular risk factors including hyperglycemia, dyslipidemia, abdominal obesity and hypertension. An effective detection of MetS not only reflects the prediction risk of diabetes mellitus and cardiovascular diseases but also helps to plan for management strategy which could reduce the healthcare burden of the society. This study aimed to compare the use of hemoglobin A1c (HbA1c) to fasting plasma glucose (FPG) as the hyperglycemic component in MetS diagnosis.

METHODS

Waist circumference, blood pressure, blood triglyceride, high-density lipoprotein (HDL)-cholesterol, FPG, and HbA1c were examined in 120 Hong Kong Chinese adults with MetS and 120 without MetS. After reviewing the subject basal characteristics, 11 of them were found with undiagnosed diabetes (FPG ≧7.0 mmol/L) and were excluded for further analysis.

RESULTS

The most prevalent MetS components among the included subjects were elevated systolic blood pressure and central obesity. Significant correlation relationships existed between FPG and HbA1c in both subject pools diagnosed with and without MetS (p < 0.001). The diagnostic rate of MetS using HbA1c was compared to FPG by the receiver operating characteristics (ROC) analysis which suggested an area under curve of 0.807 (95% CI: 0.727 to 0.887). The agreement was 90.7% in MetS-positive group with increased FPG as one of the criterion co-existed with elevated HbA1c. If including HbA1c as an additional criterion to FPG in the MetS diagnosis, 30 more participants in MetS-negative group would be MetS-positive leading to an increase in detection rate. Furthermore, 47 subjects (38 from MetS-positive group and 9 from MetS-negative group) were found having HbA1c ≧6.5%, who would have been diagnosed with diabetes based on the diagnostic criteria implemented by the Expert Group in 2009.

CONCLUSION

These findings suggest that HbA1c enhances the detection of hyperglycemia for the diagnosis of MetS.

Establishing the optimal body mass index - body esteem relationship in young adolescents

Background

This study sought to compare the utility of either inverted body mass index or body mass index to optimise the relationship with body esteem in young adolescents Design: The study was cross sectional in design and assessed body esteem and weight status in756 young adolescents (394 boys, 362 girls, mean age ± S.D. 11.4 ± 1.6 years).

Methods

Body esteem was determined using the body esteem scale for children. Height and body mass were measured directly. Body mass index was determined as kg/m² and iBMI as cm²/kg.

Results

Results indicated that the association between iBMI and body esteem was curvilinear in nature and iBMI was the better predictor of body esteem (P = .001) predicting 21.3% of the variance in body esteem scores compared to 20.5% using BMI (P = .001). When split by gender, the curvilinear relationship was still evident but significantly different between boys and girls although iBMI remained a better predictor of body esteem compared to BMI in both boys and girls. The peak differed between gender groups with the association between iBMI and body esteem peaking at 642 cm²/kg for boys and 800.64 cm²/kg for girls.

Conclusion

This study suggests that iBMI is a better predictor of body esteem in young adolescents, and that the association between body esteem and iBMI is curvilinear in nature. However, the peak of body esteem scores occured at a lower degree of leanness for boys compared to girls and indicated that the point at which body esteem scores are highest for girls is at a point of extreme leanness whereas the peak for boys was within the values considered as ‘normal’ on the leanness to obesity continuum. iBMI may therefore be a useful measure of leanness for future studies examining the association between overweight/obesity and body esteem in young adolescents.

Nutritional status, biological maturation and cardiorespiratory fitness in Azorean youth aged 11-15 years

BACKGROUND

Sex and individual differences in biological maturity status can influence height, weight, and body fat. Thus, the rigorous control of these variables seems necessary for estimating overweight and obesity in adolescents. The aims of this study were to estimate the prevalence of overweight and obesity and over-fatness in Azorean adolescents and to examine the contributions of chronological age, sex, estimated maturity status, and cardiorespiratory fitness (CRF) to the risk of overweight and obesity and over-fatness.

METHODS

The sample comprised 1,206 youth aged 11-15 years (626 boys and 580 girls) from the Azores Islands, Portugal. Body mass, stature, and skinfolds (triceps and subscapular) were measured. Body mass index (BMI) was calculated and percent fat was predicted from skinfolds. Age- and sex-specific IOTF cut-off values of the BMI defined nutritional status. Biological maturation was estimated as present height expressed as a percentage of predicted adult (mature) stature. The CRF was analyzed from the 20-m shuttle run test.

RESULTS

The total prevalence rates of overweight/obesity and over-fatness were of 31% and 27%, respectively. Low CRF (unfit) and being average and advanced in maturity status were positively and significantly associated with overweight/obesity and with risk of being over-fatness in both sexes.

CONCLUSIONS

High prevalence rates of overweight/obesity and over-fatness were identified in Azorean youth, and low CRF and advanced biological maturation were positively associated with overweight/obesity and over-fatness in our sample of adolescents.

Aptidão física relacionada à saúde de escolares: programa fitnessgram

O estudo identificou a proporção de crianças e adolescentes da população escolar de Montes Claros, Minas Gerais, Brasil, que atendem aos critérios referenciados para a saúde a partir de escores equivalentes aos componentes de aptidão física. A amostra foi constituída por 2.849 sujeitos (1.457 moças e 1.392 rapazes), com idades entre seis e 18 anos. Os componentes da aptidão física foram avaliados mediante bateria de testes composta por cinco itens: "sentar-e-alcançar" alternado, abdominal modificado, elevação do tronco, puxada em suspensão na barra modificado e caminhada/corrida de "vai-e-vem", adotando-se pontos de corte para gênero e idade sugeridos pelo Fitnessgram. Mediante análise dos resultados foi possível observar que a proporção de escolares que atenderam às exigências motoras mínimas estabelecidas que possam satisfazer aos critérios referenciados para a saúde não foi maior que 8%, e a quantidade de jovens que alcançaram os critérios foi menor a partir dos 10 anos de idade em ambos os sexos. Os dados mostram, ainda, que grande parte dos jovens estudados demonstrou componentes de aptidão física que podem comprometer melhor estado de saúde, apontando para urgente necessidade de implementar programas de intervenção direcionados ao incremento da prática de exercício físico na população escolar.