RESUMEN

Abstract Objective: To examine if the substitution of different screen time intervals with light physical activity (LPA), moderate to vigorous physical activity (MVPA) and sleep is associated with cardiovascular indicators and inflammatory markers in children. Methods: This is a cross-sectional study developed with 186 children aged between six and 11 years old from public schools in southern Brazil. CRF was measured with the 6-minute running and walking test, following the Brazil Sports Project procedures. The percentage of fat was evaluated through DXA. LPA and MVPA were measured using accelerometers. Sleep and screen time were assessed by questionnaires answered by parents. Leptin and C-reactive protein were measured by fasting blood collection. Systolic and diastolic blood pressure were determined through a digital sphygmomanometer. Isotemporal substitution models were used for statistical analysis. Results: Replacing 1 h of screen time with MVPA was associated with lower BMI, systolic and diastolic blood pressure, fat percentage, leptin, and C-reactive protein. When screen time was substituted for sleep time, lower waist circumference was observed. Regarding the substitution of 1 h of screen time with LPA, significant values were found only for leptin. Conclusion: The replacement of screen time with physical activities of different intensities and sleep time was associated with benefits in cardiovascular indicators and inflammatory markers in childhood.

RESUMEN

OBJECTIVE: To examine if the substitution of different screen time intervals with light physical activity (LPA), moderate to vigorous physical activity (MVPA) and sleep is associated with cardiovascular indicators and inflammatory markers in children. METHODS: This is a cross-sectional study developed with 186 children aged between six and 11 years old from public schools in southern Brazil. CRF was measured with the 6-minute running and walking test, following the Brazil Sports Project procedures. The percentage of fat was evaluated through DXA. LPA and MVPA were measured using accelerometers. Sleep and screen time were assessed by questionnaires answered by parents. Leptin and C-reactive protein were measured by fasting blood collection. Systolic and diastolic blood pressure were determined through a digital sphygmomanometer. Isotemporal substitution models were used for statistical analysis. RESULTS: Replacing 1 h of screen time with MVPA was associated with lower BMI, systolic and diastolic blood pressure, fat percentage, leptin, and C-reactive protein. When screen time was substituted for sleep time, lower waist circumference was observed. Regarding the substitution of 1 h of screen time with LPA, significant values were found only for leptin. CONCLUSION: The replacement of screen time with physical activities of different intensities and sleep time was associated with benefits in cardiovascular indicators and inflammatory markers in childhood.

Asunto(s)

RESUMEN

Background: There is still little understanding of the associations between physical fitness variables and bone health in children taking into account key confounders. Aim: The aim of this study was to analyze the associations between performance in tests of speed, agility, and musculoskeletal fitness (power of the upper and lower limbs) with bone mass of different regions in children, considering the adjustment to maturity-offset, lean percentage, and sex. Methods: Cross-sectional study design: the sample consisted of 160 children aged 6-11 years. The physical fitness variables tested were 1) speed, assessed with the running test at a maximum speed of 20 m; 2) agility, assessed through the 4×4-m square test; 3) lower limb power, assessed using the standing long jump test, and 4) upper limb power, assessed using the 2-kg medicine ball throw test. Areal bone mineral density (aBMD) was obtained from the analysis of body composition by dual-energy X-ray absorptiometry (DXA). Simple and multiple linear regression models were performed using the SPSS software. Results: In the crude regression analyses, the results indicated a linear relationship between all the physical fitness variables and aBMD in all body segments, but maturity-offset, sex, and lean mass percentage seemed to have an effect on these relationships. Except for the upper limb power, the other physical capacities (speed, agility, and lower limb power) were associated with aBMD in at least three body regions in the adjusted analyses. These associations occurred in the spine, hip, and leg regions, and the aBMD of the legs presented the best association magnitude (R 2). Conclusion: There is a significant association between speed, agility, and musculoskeletal fitness, specifically the lower limb power and aBMD. That is, the aBMD is a good indicator of the relationship between fitness and bone mass in children, but it is essential to consider specific fitness variables and skeletal regions.

RESUMEN

Background: The possibility of carrying out screening, with acceptable accuracy, of a child's bone mass status based on a physical fitness test can advance the concept of health-related physical fitness. In addition, the relevance of the applicability of this type of screening in educational environments is mainly due to the difficulty of direct assessments of bone health indicators. This study aimed to propose cut-off points for physical fitness tests based on children's bone health indicators. Methods: This is a two-phase cross-sectional study. Phase-1: 160 children (6-11 years-old) performed the 20-m sprint test (20-mST) and the 2 kg medicine ball throw test (2 kgMBTT). Areal bone mineral density (aBMD) and content was assessed by DXA. The area under the ROC curve greater than 70% was considered valid. Phase-2: It was carried out a secondary analysis in a sample with 8,750 Brazilians (6-11 years-old). The percentile values (identified in phase-1) were used to identify the values of the cut-off points in the unit of measurement of the tests. The validation of the cut-off points found was by odds ratio values and p ≤ 0.05. Results: Phase 1: The areas under the ROC curve were 0.710, 0.712 (boys and girls-20-mST), 0.703, and 0.806 (boys and girls-2 kgMBTT) with total spine and pelvis aBMD as the outcome. Phase 2: From percentile values, we find valid cut-off points in the Brazilian sample (OR > 3.00; p < 0.001) for boys and girls. Values ranged between 5.22 s-4.00 s to 20-mST and between 125.0 cm-160.0 cm to 2 kgMBTT. Conclusion. The 20-mST and the 2 kgMBTT presented sufficient accuracy for the screening of children aged between 6 and 11 years with greater chances of having low aBMD in the total spine and pelvis, with valid cut-off points.

RESUMEN

ABSTRACTThis systematic review and meta-analysis aimed to evaluate the effectiveness of interventions through Physical Education (PE) exercises on bone mineral content (BMC) and density (BMD) of children and adolescents. The research was conducted using the online electronic databases PubMed, Science Direct, Web of Science and Scopus (March 2021). The analysis was restricted to school-based studies that examined the effect of PE interventions on BMC and BMD in schoolchildren (<18 years old). Standardised mean differences (SMD) with 95% confidence interval (CI) and random-effects models were calculated. The heterogeneity and inconsistency of the studies were estimated using Cochran's Q-statistic and I2, respectively. Twenty-two studies with 2,556 participants were selected. PE interventions were associated with a significant increase in BMC (SMD = 1.348; 95% CI, 1.053-1.643) and BMD (SMD = 0.640; 95% CI, 0.417-0.862). Femoral neck subgroup analysis indicate an increase in BMC for boys (SMD = 1.527; 95% CI, 0.990-2.065) and girls (SMD = 1.27; 95% CI, 0.782-1.767), and in BMD for boys (SMD = 0.518; 95% CI, 0.064-0.972) and girls (SMD = 0.817; 95% CI, 0.349-1.284). Finally, increases are reported in the lumbar spine BMC for boys (SMD = 1.860; 95% CI, 1.018-2.700) and girls (SMD = 1.275; 95% CI, 0.782-1.767). This meta-analysis provides insights into the effectiveness of interventions aimed at including physical exercise in PE on bone mass, suggesting that increasing the proportion of curriculum time allocated to PE may improve students' BMD and BMC, especially in the femoral neck and lumbar spine.

Asunto(s)

RESUMEN

Background: The beneficial relationship between physical fitness and cognitive performance is affected and modulated by a wide diversity of factors that seem to be more sensitive during the development stage, particularly during early adolescence. This study aimed to examine the role of physical fitness considering the multivariate association between age, health-related quality of life (HRQOL), school vulnerability index (SVI), body mass index z-score (BMIz), physical activity, and sleep problems with the cognitive performance in boys and girls. Method: Participants were 1,196 adolescents aged 10-14 years (50.7% of boys) from Chile. Three physical fitness components and eight cognitive tasks were measured. BMIz was determined using growth references by age and sex, whereas questionaries were used to assess sleep problems, physical activity, and HRQOL. SVI was established according to the score given by the Chilean Government to educational establishments. We performed a structural equation model (SEM) to test multivariate associations among study' variables by sex. Results: Fitness was positively associated with boys' and girls' cognitive performance (ß = 0.23 and ß = 0.17; p = 0.001, respectively). Moreover, fitness presented a significant mediator role in the relationships between BMIz, SVI, and physical activity with cognitive performance (indirect effect). Additionally, SVI showed a negative association both direct and indirect effect in all three fitness components and all cognitive tasks, being this relationship stronger in girls than in boys. Conclusion: Our findings suggest that physical fitness and all its components play a crucial mediator role in the associations between several factors associated with adolescents' cognitive performance. Thereby, educational and health strategies should prioritise improving physical fitness through physical activity. They also should address other factors such as school vulnerability, obesity, and the early gender gap in a comprehensive approach boosting cognitive performance among early adolescents. Trial registration: Research Registry (ID: researchregistry5791).

RESUMEN

OBJECTIVES: The combination of sleep duration, television (TV) time and body mass index (BMI) may be related to the alteration of cardiometabolic risk. However, there are few studies that use these variables grouped, and showing the moderating role of age. This study aimed to verify if the combination of sleep duration, TV time and BMI is associated with cardiometabolic risk and the moderating role of age in this relationship in youth. METHODS: Cross-sectional study conducted with 1411 adolescents (611 male), aged 10-17 years. Sleep duration, TV time and BMI were assessed and grouped into eight categories. Cardiometabolic risk was assessed by a continuous metabolic risk score, including the following variables: low HDL-cholesterol, elevated triglycerides, dysglycemia, high systolic blood pressure, high waist circumference and low cardiorespiratory fitness. Generalized linear models were used to test moderation of age in the relationship between the eight categories of sleep duration/television time/BMI with cardiometabolic risk. RESULTS: Cardiometabolic risk factor showed association with all overweight or obesity independent of sleep time and TV time. Age moderated the relationship between sleep duration/television time/BMI with cardiometabolic risk. This association was stronger in younger adolescents (11 and 13 years), indicating that individuals with inadequate sleep, prolonged TV time and overweight/obesity present higher cardiometabolic risk values when compared to 15-year-old adolescents. CONCLUSION: Overweight/obesity, independently of sleep duration and TV time, is the main risk factor for cardiometabolic disorders in adolescence. When moderated by age, younger adolescents that presented the combination of risk factors had higher cardiometabolic risk.

Asunto(s)

RESUMEN

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

Asunto(s)

RESUMEN

Abstract Objective To assess the occurrence of an aggregate risk to cardiometabolic and musculoskeletal health of Brazilian adolescents in the period 2008/09 and 2013/14 and to identify whether there are differences in risk between the genders and in these periods. Methods This was a trend epidemiological study with a quantitative approach, consisting of a voluntary sample of adolescents from 16 Brazilian states. Data were extracted from the database of Brazil Sports Project (Projeto Esporte Brasil). Health-related physical fitness was evaluated based on body mass index, cardiorespiratory fitness, flexibility, and abdominal strength/resistance. Descriptive analysis, chi-squared test, and Poisson log regression were used for the statistical treatment. Results In the years 2008/09, 14.6% of Brazilian youngsters showed an aggregate risk to cardiometabolic health and 17.1% an aggregate risk for musculoskeletal indicators, whereas in 2013/14, the values of the risk indicators were, respectively 40.0% and 22.4%. It was observed that, in the years 2013/14, the risk to the cardiometabolic health of boys was 2.51 times greater than in 2008/09, while for girls, a three-fold increase in risk was observed. Concerning musculoskeletal health, girls showed a 2.21 risk of being in the risk zone in 2013/14 when compared with 2008/09. Conclusion The occurrence of an aggregate risk to the cardiometabolic and musculoskeletal health of Brazilian adolescents increased in the 2008/09 and 2013/14 periods. Regarding gender, an increase in the cardiometabolic and musculoskeletal risk between these periods was observed in girls. As for boys, an increase was observed only in cardiometabolic risk.

Resumo Objetivo Verificar a ocorrência de risco agregado à saúde cardiometabólica e musculoesquelética de adolescentes brasileiros no período de 2008/09 e 2013/14 e identificar se existem diferenças no risco entre os sexos e nesses períodos. Métodos Trata-se de um estudo epidemiológico de tendência com abordagem quantitativa, composto por uma amostra voluntária de adolescentes, de 16 estados brasileiros. Os dados foram extraídos da base de dados do Projeto Esporte Brasil. A aptidão física relacionada a saúde foi avaliada a partir de: índice de massa corporal, aptidão cardiorrespiratória, flexibilidade, e força/resistência abdominal. Para o tratamento estatístico foi utilizado análise descritiva, qui-quadrado e regressão Poisson log. Resultados Nos anos de 2008/09, 14,6% de jovens brasileiros apresentaram risco à saúde cardiometabólica agregada e 17,1% risco agregado dos indicadores musculoesqueléticos. Enquanto em 2013/14, os valores dos indicadores de risco foram, respectivamente 40,0% e 22,4%. Observou-se que nos anos de 2013/14 o risco à saúde cardiometabólica dos meninos era 2,51 vezes maior que em 2008/09. Já para as meninas o aumento desse risco foi de 3 vezes. No que se refere à saúde musculoesquelética, as meninas apresentaram risco de 2,21 de estar na zona de risco em 2013/14 em relação à 2008/09. Conclusão A ocorrência de risco agregado à saúde cardiometabólica e musculoesquelética de adolescentes brasileiros aumentou nos períodos de 2008/09 e 2013/14. Com relação ao sexo houve um aumento no risco cardiometabólico e musculoesquelético nas meninas entre esses períodos. Já para os meninos houve aumento apenas do risco cardiometabólico.

Asunto(s)

RESUMEN

OBJECTIVE: To assess the occurrence of an aggregate risk to cardiometabolic and musculoskeletal health of Brazilian adolescents in the period 2008/09 and 2013/14 and to identify whether there are differences in risk between the genders and in these periods. METHODS: This was a trend epidemiological study with a quantitative approach, consisting of a voluntary sample of adolescents from 16 Brazilian states. Data were extracted from the database of Brazil Sports Project (Projeto Esporte Brasil). Health-related physical fitness was evaluated based on body mass index, cardiorespiratory fitness, flexibility, and abdominal strength/resistance. Descriptive analysis, chi-squared test, and Poisson log regression were used for the statistical treatment. RESULTS: In the years 2008/09, 14.6% of Brazilian youngsters showed an aggregate risk to cardiometabolic health and 17.1% an aggregate risk for musculoskeletal indicators, whereas in 2013/14, the values of the risk indicators were, respectively 40.0% and 22.4%. It was observed that, in the years 2013/14, the risk to the cardiometabolic health of boys was 2.51 times greater than in 2008/09, while for girls, a three-fold increase in risk was observed. Concerning musculoskeletal health, girls showed a 2.21 risk of being in the risk zone in 2013/14 when compared with 2008/09. CONCLUSION: The occurrence of an aggregate risk to the cardiometabolic and musculoskeletal health of Brazilian adolescents increased in the 2008/09 and 2013/14 periods. Regarding gender, an increase in the cardiometabolic and musculoskeletal risk between these periods was observed in girls. As for boys, an increase was observed only in cardiometabolic risk.

Asunto(s)

RESUMEN

OBJETIVO: Descrever e analisar a tendência da ocorrência do baixo peso, sobrepeso e obesidade de escolares. MÉTODOS: Estudo longitudinal de tendência realizado em uma amostra voluntária de crianças e adolescentes brasileiros. A amostra foi agrupada em ano de coleta (Período I: 2005 e 2006; Período II: 2007 e 2008; e Período III: 2009 a 2011), categoria de idade (crianças: sete a 10 anos, e adolescentes: 11 a 14 anos), e estratificada por sexo. O índice de massa corporal foi utilizado para classificar o perfil nutricional. A análise da tendência foi verificada através da Regressão Logística Multinomial (p < 0,05). RESULTADOS: As médias de ocorrências foram de 2,11% no baixo peso, 22,27% no sobrepeso e 6,8% na obesidade. Identificou-se chance do baixo peso diminuir do período I para o II nos adolescentes do sexo masculino, e de aumentar nas crianças do sexo feminino do período II para o III. No sobrepeso, encontramos chance de aumento seguida de diminuição nas crianças do sexo masculino. Na obesidade, em todas as categorias de idade e em ambos os sexos, houve chance de aumento do período I para o II. CONCLUSÃO: A prevalência do baixo peso apresenta valores menores que 5% em todas as categorias de idade e sexo. No entanto, na categoria do sobrepeso e da obesidade, encontramos ocorrências mais elevadas, atingindo, juntas, quase 30% da população infanto-juvenil brasileira; além disso, evidenciamos uma chance de aumento na prevalência da obesidade até o ano de 2008 e, após, uma manutenção destas altas prevalências.

OBJECTIVE: To describe and analyze the trends of occurrence of underweight, overweight, and obesity in schoolchildren. METHODS: This was a longitudinal study of trends conducted in a voluntary sample of Brazilian children and adolescents. The sample was grouped by year of collection (period I: 2005 and 2006; period II: 2007 and 2008, and period III: 2009-2011), age category (children: 7 to 10 years, and adolescents: 11 to 14 years), and stratified by gender. The body mass index was used to classify the nutritional profile. Trend analysis was verified using multinomial logistic regression (p < 0.05). RESULTS: Mean occurrences were 2.11% for underweight, 22.27% for overweight, and 6.8% for obesity. There was a decrease of underweight in male adolescents from period I to II, as well as an increase in female children from period II to III. Regarding overweight, there was an increase followed by a decrease in male children. Regarding obesity, there was an increase from period I to II in all age groups and for both genders. CONCLUSION: The prevalence of underweight was less than 5% in all categories of age and gender. However, the categories of overweight and obesity showed higher values, and together comprised almost 30% of the young Brazilian population; moreover, a trend toward increase in prevalence of obesity was observed up to the year 2008, followed by the maintenance of these high prevalence rates.

Asunto(s)

RESUMEN

OBJECTIVE: To describe and analyze the trends of occurrence of underweight, overweight, and obesity in schoolchildren. METHODS: This was a longitudinal study of trends conducted in a voluntary sample of Brazilian children and adolescents. The sample was grouped by year of collection (period I: 2005 and 2006; period II: 2007 and 2008, and period III: 2009-2011), age category (children: 7 to 10 years, and adolescents: 11 to 14 years), and stratified by gender. The body mass index was used to classify the nutritional profile. Trend analysis was verified using multinomial logistic regression (p<0.05). RESULTS: Mean occurrences were 2.11% for underweight, 22.27% for overweight, and 6.8% for obesity. There was a decrease of underweight in male adolescents from period I to II, as well as an increase in female children from period II to III. Regarding overweight, there was an increase followed by a decrease in male children. Regarding obesity, there was an increase from period I to II in all age groups and for both genders. CONCLUSION: The prevalence of underweight was less than 5% in all categories of age and gender. However, the categories of overweight and obesity showed higher values, and together comprised almost 30% of the young Brazilian population; moreover, a trend toward increase in prevalence of obesity was observed up to the year 2008, followed by the maintenance of these high prevalence rates.

Asunto(s)