Sports participation and adiposity do not mediate the relationship between birth weight and arterial thickness in adolescents: ABCD Growth Study.

OBJECTIVE: To analyse the relationship of altered birth weight with metabolic and cardiovascular outcomes among adolescents, as well as to identify if sports participation is able to attenuate or even eliminate the impact of birth weight on health outcomes. METHODS: Cross-sectional study (Analysis of Behaviours of Children During Growth [ABCD Growth Study]). Adolescents with age ranging from 11 to 18 years old (14.7±2.1) stratified according to normal (n = 230) and altered (n = 35) birth weight composed the sample. Birth weight was self-reported by adolescent's parents. Sports participation was assessed by face-to-face interview. Carotid intima-media thickness (CIMT) and femoral intima-media thickness (FIMT) were measured using an ultrasound device. C-reactive protein levels were used to assess the inflammatory status. Blood pressure, Z score of metabolic risk (dyslipidemia and glucose), adiposity, and insulin resistance were covariates. RESULTS: In the crude model, FIMT (p value = 0.037) and C-reactive protein (p value = 0.029) were affected by altered birth weight. In the adjusted models, altered birth weight affected FIMT (p value = 0.048; small effect size of 1.7%), independently of sports participation. For C-reactive protein, previous time of engagement in sports (p value = 0.001; small effect size of 4.8%) affected C-reactive protein, independently of birth weight. CONCLUSION: Vascular structure seems to be affected by birth weight in adolescents, while its impact on inflammation seems to be attenuated by the regular engagement in sports.

Sports participation is inversely associated with C-reactive protein levels in adolescents: ABCD Growth Study.

OBJECTIVE: To analyze the relationship between sports participation and C-reactive protein (CRP) levels in adolescents and to identify the possible role of mediation developed by trunk fatness (TF). METHODS: Cross-sectional design, part of the longitudinal study entitled "Analysis of Behaviors of Children During Growth" (ABCD Growth Study), Presidente Prudente, SP, Brazil. The sample comprised 259 adolescents (14.7 ± 2.1 [182 boys and 77 girls]) stratified according to sex and engagement in sports in agreement with the inclusion criteria: absence of any known diseases; previous engagement in sports for at least 12 months (≥300 minutes weekly); no regular engagement in sports in the previous 12 months (non-regular sports participation or <300 min/wk); written parental consent and adolescents' assent both signed. Engagement in sports was self-reported. CRP levels were used to assess the inflammatory status. TF was estimated by a densitometer scanner. Age, biological maturation, HOMA-IR, and blood pressure were treated as covariates. RESULTS: There was no mediation effect of TF in the association of any indicators of sports practice and CRP. However, a direct effect of sports was observed on CRP levels when considering previous months of engagement, frequency, and volume of sports for boys and also previous months of engagement in sports for girls. CONCLUSION: Previous sports participation and the amount of engagement in sports per week (≥300 min/wk) presented an inverse relationship with CRP levels; however, trunk fatness did not mediate this process.

Adiposity and Physical Activity Do Not Mediate the Longitudinal Association Between Sleep Quality and Arterial Thickness Among Adolescents.

STUDY OBJECTIVES: Sleep is a behavior with the potential to affect cardiovascular health. Given the fact that adiposity and physical activity seem to be related to cardiovascular risk factors during growth, it is still unclear whether sleep quality could affect arterial thickness among adolescents. Thus, the objective of the current study was to analyze the effect of sleep quality on arterial thickness and identify the possible mediation role of physical activity and trunk fat in adolescents. METHODS: This was a longitudinal study (12-month follow-up) composed of 71 adolescents with ages ranging from 11 to 14 years at baseline (absence of any known chronic diseases, and no regular medicine use). All variables were assessed twice (baseline and 12-month follow-up): (1) sleep quality was reported using the Mini Sleep Questionnaire (MSQ); (2) physical activity was estimated using pedometers; (3) trunk fat was assessed using a densitometry scanner; and (4) carotid intima-media thickness (CIMT) and femoral intima-media thickness (FIMT) were assessed using ultrasonography. RESULTS: Adolescents who presented poor sleep quality demonstrated significantly increased FIMT (r = .299, 95% confidence interval .071 to .498) and for every point increase in the MSQ score from baseline to follow-up there was a 1.12% (95% confidence interval 0.26 to 1.98) increase in FIMT over time. Moreover, trunk fat and physical activity did not mediate the association between sleep quality and arterial thickness, but FIMT had a positive and independent relationship only with trunk fat. CONCLUSIONS: Sleep quality was positively associated with FIMT among adolescents, whereas physical activity and adiposity did not mediate this process.

Association between Cluster of Lifestyle Behaviors and HOMA-IR among Adolescents: ABCD Growth Study.

Objective: To analyze the association of potential risk factors to health with body fatness and insulin resistance. Baseline measures of the ongoing longitudinal Analysis of Behaviors of Children During (ABCD) Growth Study. Materials and Methods: The sample was composed of 280 adolescents of both sexes (198 boys and 82 girls) aged from 10 to 18 years. Four risk factors were considered, as follows: no sports practice, skipping breakfast, poor sleep quality, and TV viewing. The outcomes considered were insulin resistance (HOMA-IR) and body fatness (densitometer scanner). Age, sex, maturity offset, and ethnicity were treated as covariates. Results: No sports practice and skipping breakfast were associated with higher body fatness (Sports practice: Wald: 8.786; p = 0.003. Breakfast: Wald: 9.364; p = 0.002). Poor sleep quality was related to a greater HOMA-IR index (Wald: 6.013; p = 0.014). Adolescents with ≥3 risk factors presented a higher risk of high HOMA-IR (OR = 4.89 (95%CI: 1.61 to 14.84)) than their counterparts with no risk factors. Conclusion: Lifestyle risk factors seem relevant to affect obesity and insulin resistance, while the aggregation of these risk factors affects insulin resistance, independent of adiposity.

Physical Activity and Skipping Breakfast Have Independent Effects on Body Fatness Among Adolescents.

OBJECTIVE: We analyzed the longitudinal relationship between breakfast intake and adiposity among adolescents, and the possible mediation role of physical activity on this phenomenon. METHODS: We conducted the longitudinal study composed of 86 adolescents (11-14 years old), absence of any known chronic diseases and no regular medicine use that returned the formal consent and assent both signed. Breakfast intake was reported through face-to-face interviews. Adiposity was assessed using a densitometry scanner. Physical activity was estimated through step counts performed using pedometers. Biological maturation was estimated through the maturity level. Student t test for independent samples was used to compare adolescents who were "nonskipping breakfast" and "skipping breakfast," whereas the relationship between adiposity, physical activity, and skipping breakfast was assessed using Pearson correlation. Structural equation model was created to identify the mediation role of physical activity on the relationship between nonskipping breakfast and adiposity. RESULTS: After 12 months, adolescents who had consumed breakfast regularly presented decreased trunk fatness (-3.5% [95% confidence interval (CI): -6.9 to -0.2]) and body fatness (-2.3% [95% CI: -3.9 to -0.7]) compared with their counterparts. Physical activity had an inverse relationship with trunk fatness (r = -0.270 [95% CI: -0.457 to -0.060]). Nonskipping breakfast was, however, not significantly related to trunk fatness; however, physical activity seems to reduce trunk fatness in our sample (r = -0.281; 95% CI: -0.479 to -0.083). CONCLUSIONS: Adolescents who ate breakfast regularly presented lower body fatness independent of physical activity, whereas trunk fatness decreased in adolescents who improved physical activity.

Sport-based physical activity recommendations and modifications in C-reactive protein and arterial thickness.

We analyzed the effects of 1 year of engagement in ≥ 300 min/week of organized sports on inflammatory levels and vascular structure in adolescents. The sample was composed of 89 adolescents (11.6 ± 0.7 years old [43 boys and 46 girls]), stratified according to engagement in ≥ 300 min/week of sport practice during at least 12 months of follow-up (n = 15, sport practice; n = 74, non-sport practice). Arterial thickness (carotid and femoral) was assessed by ultrasound scan, while high sensitive C-reactive protein levels were used to assess inflammatory status. Trunk fatness (densitometry scanner), biological maturation (age at peak height velocity), blood pressure, and skipping breakfast were treated as covariates. Independently of body fatness and biological maturation, the group engaged in sports presented a higher reduction in C-reactive protein (mean difference -1.559 mg/L [95%CI -2.539 to -0.579]) than the non-sport group (mean difference -0.414 mg/L [95%CI -0.846 to 0.017]) (p = 0.040). There was a significant relationship between changes in C-reactive protein and changes in femoral intima-media thickness in the non-sport group (r = 0.311 [95%CI 0.026 to 0.549]). CONCLUSION: Inflammation decreased in adolescents engaged in organized sports, independently of trunk fatness and biological maturation. Moreover, inflammation was related to arterial thickening only in adolescents not engaged in sports. What is Known: • Intima media thickness is a relevant marker of cardiovascular disease in pediatric groups, being affected by obesity and inflammation. • The importance of monitoring inflammatory markers from childhood is enhanced by the fact that alterations in these inflammatory markers in early life predict inflammation and alterations in carotid IMT in adulthood. What is New: • Anti-inflammatory properties related to physical exercise performed at moderate intensity, on inflammation and alterations in IMT are not clear in pediatric groups. • Due to the importance that sport participation has assumed as a promoter of improvements in health and quality of life, it is necessary to understand its potential benefits for cardiovascular health during human growth.

The Impact of Training Load on Bone Mineral Density of Adolescent Swimmers: A Structural Equation Modeling Approach.

PURPOSE: To investigate the mediating effect of muscle mass on the relationship between training load and bone density in adolescent swimmers. METHODS: A cross-sectional study involving 87 control and 22 swimmers aged 10-19 years (overall sample: n = 109). Swimmers had a minimum of 1 year of competition in regional and national championships, and control adolescents reported 1 year without any organized sport. Bone density was the main outcome (dual-energy X-ray absorptiometry), which was measured in upper limbs, lower limbs, spine, and whole body. Monthly training load was the independent variable, while the mediation effect of lean soft tissue was assessed. Maturity offset, age, inflammation, and vitamin D intake were treated as covariates. RESULTS: Swimmers had lower bone density than controls; there was a significant and positive relationship between training load and muscle mass. In boys, training load presented a negative correlation with bone density in lower limbs [r = -.293; 95% confidence interval (CI), -.553 to -.034]. In girls, training load was negatively related to bone mineral density in lower limbs (r = .563; 95% CI, -.770 to -.356) and whole body (r = -.409; 95% CI, -.609 to -.209). CONCLUSION: Training load had a negative relationship on bone density of swimmers of both sexes, independently of the positive effect of lean soft tissue on bone density.

Accuracy of different cutoff points of body mass index to identify overweight according to body fat values estimated by DEXA / Precisão de diferentes pontos de corte do índice de massa corporal para identificar sobrepeso de acordo com valores de gordura corporal estimados por DEXA

Abstract: Objective: To evaluate the sensitivity and specificity of different cutoff points of body mass index for predicting overweight/obesity according to body fat values estimated by DEXA among Brazilian adolescents. Methods: Cross-sectional study including 229 male adolescents aged 10-15 years, in which body adiposity and anthropometric measures were assessed. Nutritional status was classified by BMI according to cutoff points described in scientific literature. Results: Moderate agreements were observed between body fat estimated by DEXA and cutoffs proposed by Cole et al. (K = 0.61), Conde and Monteiro (K = 0.65), Must et al. (K = 0.61) and WHO (K = 0.63). The BMI in continuous form showed good agreement with the Dexa (ICC = 0.72). The highest sensitivity was observed for cutoff by Conde and Monteiro (0.74 [0.62, 0.84]) and the highest specificity by Cole et al. (0.98 [0.94, 0.99]). For the areas under the ROC curve of cutoff points analyzed, significant difference comparing the cutoff points by Cole et al. and Conde and Monteiro (0.0449 [0.00294, 0.0927]) was observed. Conclusions: The cutoff proposed by Conde and Monteiro was more sensitive in identifying overweight and obesity when compared to the reference method, and the cutoff proposed by Cole et al. presented the highest specificity for such outcomes.

Resumo: Objetivo: Avaliar a sensibilidade e a especificidade de diferentes pontos de corte do índice de massa corporal para o prognóstico de sobrepeso/obesidade de acordo com os valores de gordura corporal estimados por absorciometria de raios X de dupla energia (DEXA) entre adolescentes brasileiros. Métodos: Estudo transversal que inclui 229 adolescentes do sexo masculino entre 10-15 anos, no qual foram avaliadas a adiposidade corporal e as medidas antropométricas. A situação nutricional foi classificada pelo IMC de acordo com os pontos de corte descritos na literatura científica. Resultados: Foram observadas concordâncias moderadas entre a gordura corporal estimada por DEXA e os cortes propostos por Cole et al. [K = 0,61], Conde e Monteiro [K = 0,65], Must et al. [K = 0,61] e a Organização Mundial de Saúde (OMS) [K = 0,63]. O IMC de forma contínua mostrou uma boa concordância com a DEXA [CCI = 0,72]. A maior sensibilidade foi observada em cortes por Conde e Monteiro [0,74 (0,62, 0,84)] e a maior especificidade por Cole et al. [0,98 (0,94, 0,99)]. Nas áreas abaixo da curva de ROC de pontos de corte analisados, foi observada uma diferença significativa ao se compararem os pontos de corte de Cole et al. e Conde e Monteiro [0,0449 (0,00294, 0,0927)]. Conclusões: O corte proposto por Conde e Monteiro foi mais sensível na identificação de sobrepeso e obesidade em comparação com o método de referência e o corte proposto por Cole et al. apresentou a maior especificidade para esses resultados.

Accuracy of different cutoff points of body mass index to identify overweight according to body fat values estimated by DEXA.

OBJECTIVE: To evaluate the sensitivity and specificity of different cutoff points of body mass index for predicting overweight/obesity according to body fat values estimated by DEXA among Brazilian adolescents. METHODS: Cross-sectional study including 229 male adolescents aged 10-15 years, in which body adiposity and anthropometric measures were assessed. Nutritional status was classified by BMI according to cutoff points described in scientific literature. RESULTS: Moderate agreements were observed between body fat estimated by DEXA and cutoffs proposed by Cole et al. (K=0.61), Conde and Monteiro (K=0.65), Must et al. (K=0.61) and WHO (K=0.63). The BMI in continuous form showed good agreement with the Dexa (ICC=0.72). The highest sensitivity was observed for cutoff by Conde and Monteiro (0.74 [0.62, 0.84]) and the highest specificity by Cole et al. (0.98 [0.94, 0.99]). For the areas under the ROC curve of cutoff points analyzed, significant difference comparing the cutoff points by Cole et al. and Conde and Monteiro (0.0449 [0.00294, 0.0927]) was observed. CONCLUSIONS: The cutoff proposed by Conde and Monteiro was more sensitive in identifying overweight and obesity when compared to the reference method, and the cutoff proposed by Cole et al. presented the highest specificity for such outcomes.

Changes in body fatness affect cardiovascular outcomes more than changes in physical activity.

OBJECTIVE: The aim of this study was to analyse whether changes in physical activity and body fatness are related to modifications in cardiovascular risk factors among adolescents. Material and methods A sample of 89 healthy adolescents was recruited for this study. We assessed habitual physical activity, body fat percentage, arterial thickness, blood sample, and biological maturation. Multivariate models were used to analyse the relationships between independent and dependent variables. RESULTS: Physical activity (mean difference: 429.4 steps [95% confidence interval=-427 to 1286]) and body fatness (mean difference: -0.7% [95% confidence interval=-1.6-0.2]) remained stable during the study period. Independent of changes in physical activity, for each percentage increase in body fatness, femoral intima-media thickness increased by 0.007 mm (ß=0.007 [95% confidence interval=0.001-0.013]). Longitudinal relationships were found for high-density lipoprotein-cholesterol (ß=-0.477 mg/dl [95% confidence interval=-0.805 to -0.149]) and triacylglycerol (ß=2.329 mg/dl [95% confidence interval=0.275-4.384]). CONCLUSION: Changes in body fatness are more important than the amount of physical activity on cardiovascular and metabolic risks.

High Blood Pressure Combined with Sedentary Behavior in Young People: A Systematic Review.

BACKGROUND: High blood pressure (HBP) is a cardiovascular risk factor that can initiate in childhood and adolescence and may be associated with other risk factors such as sedentary lifestyles. Therefore, verifying if these associations occur from the earliest ages is of fundamental importance. OBJECTIVES: to report the prevalence of HBP combined with sedentary behavior through a systematic review. DESIGN AND METHODS: The research was performed based on studies published between 2010 and 2016 in Medline, Web of Science, Excerpta Medica (EMBASE), and Scielo, using terms related to: 'sedentary behavior' OR 'screen time' AND 'high blood pressure'. In the initial search, 821 studies were found and after exclusions twelve studies were included in the review. RESULTS: Twelve studies addressing the relationship between sedentary behavior and HBP were found. Eighty-three percent of the studies evaluated sedentary behavior using a questionnaire (n = 10). The majority of studies analyzed in the review were conducted in North America (41.6%). Only four studies presented the prevalence of HBP related to sedentary behavior (variation 1-22.9%). In seven studies a close relationship between sedentary behavior and HBP was observed. CONCLUSIONS: Although most studies observed a relationship between sedentary behavior and HBP, the results still need to be further explained. Based on the findings of this review, follow-up studies and objective measurements of time spent in sedentary behavior in young people could help to determine the cause-effect relationship between sedentary behavior and HBP in pediatric populations.

Impact of physical exercise/activity on vascular structure and inflammation in pediatric populations: A literature review.

PURPOSE: To describe the effects of physical exercise/activity on the vascular architecture of children and adolescents, as well as to identify the effects of inflammation and sedentary behaviors on this relationship. METHODS: Potentially relevant articles were identified in the databases MEDLINE and PubMed covering the period from 2000 to 2015. No language restrictions were applied. RESULTS: Thirteen articles were found that included obese boys and girls in their samples (aged 9-19). Six interventional studies assessed inflammation and in five of these, physical exercise decreased inflammation. In 10 studies, vascular architecture was affected by physical exercise/activity. CONCLUSIONS: The impact of physical exercise on vascular architecture and inflammation seems relevant, but has been mainly investigated in obese groups. PRACTICAL IMPLICATIONS: Health professionals should act together in organized interventions in schools, targeting the promotion of higher physical activity levels in children and adolescents.

Breakfast frequency, adiposity, and cardiovascular risk factors as markers in adolescents.

OBJECTIVE: To analyse the relationship between skipping breakfast and haemodynamic, metabolic, inflammatory, and cardiovascular risk factors in adolescents. METHODS: A cross-sectional study was carried out with information from an ongoing cohort study in Presidente Prudente, São Paulo, Brazil. The sample comprised of 120 adolescents (11.7±0.8 years old) who met the following inclusion criteria: age between 11 and 14 years; enrolled in the school unit of elementary education; absence of any known disease; and no drug consumption. The parents or legal guardians of the patients signed a formal informed consent. Skipping breakfast was self-reported through face-to-face interviews. Blood pressure, intima-media thickness, trunk fatness, total and fractional cholesterol levels - high-density lipoprotein cholesterol and low-density lipoprotein cholesterol - triacylglycerol levels, and high-sensitivity C-reactive protein levels were measured. RESULTS: In this study, 47.5% (95% CI: 38.5-56.4%) of the adolescents reported skipping breakfast at least 1 day/week. Adolescents who skipped breakfast had higher values of trunk fatness and systolic blood pressure. Breakfast frequency was negatively related to systolic blood pressure (ß -1.99 [-3.67; -0.31]) and z score dyslipidaemia (ß -0.46 [-0.90; -0.01]), but this relationship was mediated by trunk fatness. CONCLUSION: Skipping breakfast is related to cardiovascular risk factors in adolescents, and this relationship was mainly mediated by trunk fatness.

Cardiovascular and metabolic risk markers are related to parasympathetic indices in pre-pubertal adolescents.

OBJECTIVE: To analyse the relationship between different heart rate variability indices, resting heart rate, and cardiovascular markers in adolescents. METHODS: A cross-sectional study was carried out with information from an ongoing cohort study. The sample was composed of 99 adolescents who complied with the following inclusion criteria: aged between 11 and 14 years; enrolled in a school unit of elementary education; absence of any known diseases; no drug consumption; and a formal consent signed by the parents or legal guardians. Weight, height, heart rate variability, lipid profile, inflammatory markers, blood pressure, resting heart rate, intima-media thickness, blood flow, and trunk fatness were measured. Partial correlation and linear regression (expressed by ß and 95% confidence intervals [95%CI]) analyses were used to analyse the relationships between the variables. RESULTS: In the linear regression analysis, even after adjustments for sex, age, trunk fatness, and somatic maturation, parasympathetic activity presented significant correlations with maximum carotid artery blood flow (ß=-0.111 [95%CI=-0.216; -0.007]), systolic blood pressure (ß=-0.319 [95%CI=-0.638; -0.001]), and resting heat rate (ß=-0.005 [95%CI=-0.009; -0.002]). CONCLUSION: Parasympathetic activity at rest is inversely related to maximum and minimum blood flow, triacylglycerol levels, and systolic blood pressure. These findings suggest that heart rate variability has the potential to discriminate pre-pubertal adolescents at increased risk.

Sports practice is related to parasympathetic activity in adolescents / Prática esportiva está relacionada à atividade parassimpática em adolescentes

OBJECTIVE: To analyze the relationship among sports practice, physical education class, habitual physical activity and cardiovascular risk in adolescents. METHODS: Cross-sectional study with 120 schoolchildren (mean: 11.7±0.7 years old), with no regular use of medicines. Sports practice and physical education classes were assessed through face-to-face interview, while habitual physical activity was assessed by pedometers. Bodyweight, height and height-cephalic trunk were used to estimate maturation. The following variables were measured: body fatness, blood pressure, resting heart rate, blood flow velocity, intima-media thickness (carotid and femoral) and heart rate variability (mean between consecutive heartbeats and statistical index in the time domain that show the autonomic parasympathetic nervous system activity root-mean by the square of differences between adjacent normal R-R intervals in a time interval). Statistical treatment used Spearman correlation adjusted by sex, ethnicity, age, body fatness and maturation. RESULTS: Independently of potential confounders, sports practice was positively related to autonomic parasympathetic nervous system activity (â=0.039 [0.01; 0.76]). On the other hand, the relationship between sport practice and mean between consecutive heartbeats (â=0,031 [-0.01; 0.07]) was significantly mediated by biological maturation. CONCLUSIONS: Sport practice was related to higher heart rate variability at rest.

OBJETIVO: Analisar a relação entre prática esportiva, educação física escolar, atividade física habitual e indicadores cardiovasculares de risco em adolescentes. MÉTODOS: Estudo transversal que selecionou 120 escolares (idade média 11,7±0,7 anos), sem consumo de medicamentos. Prática esportiva fora do ambiente escolar e educação física escolar foram avaliadas por entrevista face a face, enquanto a atividade física habitual foi avaliada por pedometria. Peso corporal, estatura e altura troncocefálica foram usados para estimar a maturação biológica. Foram avaliados: gordura corporal, pressão arterial, frequência cardíaca durante o repouso, velocidade do fluxo sanguíneo, espessura mediointimal das artérias (carótida e femoral), variabilidade da frequência cardíaca (média entre batimentos cardíacos consecutivos e o índice estatístico no domínio do tempo que representa atividade do sistema nervoso autônomo parassimpático por meio da raiz quadrada da média das diferenças sucessivas ao quadrado entre intervalos R-R consecutivos). Correlação de Spearman verificou relação entre as variáveis. Relacionamentos significativos foram ajustados por: sexo, etnia, idade, gordura corporal e maturação biológica. RESULTADOS: Prática esportiva, independentemente dos ajustes, apresentou correlação positiva com atividade do sistema nervoso autônomo parassimpático (ß=0,039 [0,01; 0,76]). Por outro lado, a relação entre tal engajamento e a média entre os intervalos R-R (ß=0,031 [-0,01; 0,07]) foi mediada pela maturação biológica. CONCLUSÕES: A prática esportiva foi relacionada a uma maior variabilidade da frequência cardíaca durante o repouso.

[Sports practice is related to parasympathetic activity in adolescents]. / Prática esportiva está relacionada à atividade parassimpática em adolescentes.

OBJECTIVE: To analyze the relationship among sports practice, physical education class, habitual physical activity and cardiovascular risk in adolescents. METHODS: Cross-sectional study with 120 schoolchildren (mean: 11.7±0.7 years old), with no regular use of medicines. Sports practice and physical education classes were assessed through face-to-face interview, while habitual physical activity was assessed by pedometers. Body weight, height and height-cephalic trunk were used to estimate maturation. The following variables were measured: body fatness, blood pressure, resting heart rate, blood flow velocity, intima-media thickness (carotid and femoral) and heart rate variability (mean between consecutive heartbeats and statistical index in the time domain that show the autonomic parasympathetic nervous system activity root-mean by the square of differences between adjacent normal R-R intervals in a time interval. Statistical treatment used Spearman correlation adjusted by sex, ethnicity, age, body fatness and maturation. RESULTS: Independently of potential confounders, sports practice was positively related to autonomic parasympathetic nervous system activity (ß=0.039 [0.01; 0.76]). On the other hand, the relationship between sport practice and mean between consecutive heartbeats (ß=0,031 [-0.01; 0.07]) was significantly mediated by biological maturation. CONCLUSIONS: Sport practice was related to higher heart rate variability at rest.

Possible underestimation by sports medicine of the effects of early physical exercise practice on the prevention of diseases in adulthood.

In modern society, combatting cardiovascular and metabolic diseases has been highlighted as an urgent global challenge. In recent decades, the scientific literature has identified that behavioral variables (e.g. smoking, unhealthy diet and physical inactivity) are related to the development of these outcomes and, therefore, preventive actions should focus on the promotion of physical exercise practice and a healthy diet, as well as combatting the smoking habit from an early age. The promotion of physical exercise in the general population has been suggested as a relevant goal by significant health organizations around the world. On the other hand, recent literature has indicated that physical exercise performed in early life prevents the development of diabetes mellitus, dyslipidemia and arterial hypertension during adulthood, although this protective effect seems to be independent of the physical activity performed during adulthood. Apparently, the interaction between physical exercise and human growth in early life constitutes an issue which is not completely understood by sports medicine. The aim of the present review was therefore to discuss recent evidence on the effects of physical exercise performed during childhood and adolescence on cardiovascular and metabolic outcomes in adulthood.

The mediating role of physical inactivity on the relationship between inflammation and artery thickness in prepubertal adolescents.

OBJECTIVE: To analyze the relationship between inflammatory markers and the lipid profile, blood flow, and artery structure in prepubertal adolescents stratified according to sports practice. STUDY DESIGN: The sample was composed of 120 adolescents (57 boys and 63 girls) with a mean age of 11.7 ± 0.7 years (ranging from 11 to 13 years). Intima-media thickness (IMT) and blood flow were measured with ultrasonography. The lipid profile and high-sensitivity C-reactive protein were measured after the subjects had fasted for 12 hours overnight. Trunk fatness was measured by dual-energy x-ray absorptiometry. Organized sports participation was analyzed as a categorical variable. Biological maturation was determined via the age at peak height velocity. RESULTS: In the adjusted model, high-sensitivity C-reactive protein was significantly related to high-density lipoprotein-cholesterol (ß = -5.797 [-11.500 to -0.093]), femoral IMT (ß = 0.062 [0.008-0.116]), and the sum of femoral and carotid IMT (ß = 1.107 [0.223-1.919]), but only in the group without sports participation. Slopes of the crude linear regression were greater in the group without sports participation for femoral IMT (t = 2.621; P = .009) and the sum of femoral and carotid IMT (t = 2.876; P = .004) when compared with the group with sports participation. CONCLUSION: Independent of body fatness and biological maturation, inflammatory status was related to artery IMT and dyslipidemia in prepubertal adolescents, modulated by sport participation.

Treinamento concorrente e o treinamento funcional promovem alterações benéficas na composição corporal e esteatose hepática não alcoólica de jovens obesos / Concurrent training and functional training promotes beneficial changes in body composition and nonalcoholic fatty liver of obese youth

Comparar efeito do treinamento concorrente e o treinamento funcional na composição corporal, perfil lipídico e esteatose hepática não alcoólica (EHNA) em adolescentes obesos. Estudo longitudinal/analítico por amostragem não aleatória. Amostra de 49 adolescentes obesos (treinamento concorrenteENT#091;n=36ENT#093;; treinamento funcionalENT#091;n=13ENT#093;). Nos dois tipos de treinamento físico 50% de atividade aeróbia, e 50% resistida (concorrente: musculação; funcional: peso do próprio corpo e/ou pesos livres). Para distribuição normal aplicou-se Teste t de Student para dados pareados. Treinamento concorrente apresentou redução para lipoproteína de baixa densidade (-16,45%), colesterol total (-11,55%), gordura corporal (-8,52%) e gordura de tronco (-9,95%) e aumento da massa muscular (5,05%). Treinamento funcional reduziu 76,9% a ocorrência da EHNA, gordura corporal (-4,97%), gordura intra-abdominal (-19,90%), e aumento na massa muscular (4,18%). Devido ao alto acometimento da EHNA neste grupo, futuras investigações se fazem necessárias. Para tanto, o treinamento concorrente parece ser uma ferramenta útil para o tratamento da EHNA em adolescentes obesos.

To compare the effect of concurrent and functional exercise training on body composition, lipid profile and non-alcoholic steatohepatitis in obese adolescents. Longitudinal/analytical study by non-random sampling carried out with 49 obese adolescents (n=36 in concurrent and n=13 in functional exercise training). Both protocols had 50% of the session designed to aerobic activities and the other half session to resistance and functional training (activities using self-body weight and dumbbells). Set data had normal distribution and the paired sample t test was applied. Concurrent exercise training decreased low density lipoprotein (-16.45%), total cholesterol (-11.55%), body fatness (-8.52%), trunk fatness (-9.95%) and increased fat free mass (5.05%). On the other hand, functional exercise training decrease body fatness (-4.97%), trunk fatness (-5.11%), intra-abdominal adiposity (-19,9%), increase fat free mass (4.18%) and occurrence of non-alcoholic steatohepatitis (reduction of 76.9%). Concurrent training seems a relevant tool to the treatment of non-alcoholic steatohepatitis in obese adolescents.

Effect of swimming training on stress-related metabolic parameters of diabetic and non-diabetic rats / Efeito do treinamento de natação sobre estresse metabólico de ratos diabéticos e não diabéticos

Physical training can be an useful strategy to attenuate the stress markers concentrations and hyperglycemia on type 1 diabetic rats. Thus, the purpose of the present study was to investigate the effects of swimming training on metabolic parameters and stress markers in diabetic and non-diabetic rats. Twenty-four adult male Wistar rats were recruited. The rats were randomly divided into four groups, sedentary control (SC), trained control (TC), sedentary diabetic (SD), and trained diabetic (TD). The diabetic rats received alloxan monohydrate and the trained rats swam for 60 minutes five times per week. The training load was 3.5% and 5% of body weight to diabetic and non-diabetic rats, respectively. After the euthanasia, blood samples for determination of corticosterone, insulin, and glucose levels were collected, and the adrenal weight, adrenal cholesterol concentration, gastrocnemius glycogen concentration, and muscle total protein content were also determined. To compare the groups, a variance analysis was used with Tukey´s post-hoc. The significance level of 5% was adopted. The adrenal weight was higher in SD (17.2±0.6g) than the other groups (SC: 12.2±0.8g; TC: 13.7±0.6g; TD: 14.3±0.8g), and TD had similar values of TC. The corticosterone level of SD was higher than SC and TC. The serum glucose was higher in the diabetic groups and insulin was lower in these groups. Six weeks of swimming training was efficient to reduce stress markers concentration in type 1 rats. Training may be a good tool to avoid the reduction on muscle protein content in type 1 diabetic rats.

Treinamento físico pode ser uma estratégia útil para atenuar as concentrações de marcadores de estresse e hiperglicemia em ratos diabéticos tipo 1. Assim, objetivo do estudo foi investigar o efeito do treinamento de natação sobre os parâmetros metabólicos e marcadores de estresse em ratos diabéticos e não diabéticos. Foram selecionados vinte e quatro ratos machos Wistar divididos em quatro grupos, controle sedentário (SC), controle treinado (TC), diabético sedentário (SD) e diabético treinado (TD). A indução de diabetes foi por aloxana monoidratada. Os ratos foram submetidos a 60 minutos de natação cinco vezes por semana com carga de 3,5% e 5% do peso corporal para ratos diabéticos e não diabéticos, respectivamente. Depois da eutanásia, foram determinados corticosterona, insulina, glicose, peso da adrenal, concentração de colesterol da adrenal e glicogênio do músculo gastrocnêmio e conteúdo proteico total muscular também foram determinados. Foi aplicada análise de variância e Post Hoc de Tukey, com significância estatística menor que 5%. Peso da adrenal foi maior em SD (17.2±0.6g) que nos outros grupos (SC: 12.2 ±0.8g; TC: 13.7±0.6g; TD: 14.3±0.8g) e TD apresentou valores similares de TC. A corticosterona de SD foi maior do que SC e TC. Glicose sérica foi elevada no grupo diabético e a insulina foi menor neste grupo. Seis semanas de treinamento de natação foram eficientes para reduzir a concentração de marcadores de estresse em ratos diabéticos tipo 1. O treinamento de natação pode ser uma ferramenta útil para evitar a redução do conteúdo proteico muscular em ratos diabéticos tipo 1.