Screen time, sleep duration, leisure physical activity, obesity, and cardiometabolic risk in children and adolescents: a cross-lagged 2-year study.

BACKGROUND: Considering the previous research that suggested that screen time (ST), sleep duration, physical activity (PA), obesity and cardiometabolic risk factors are related, it is essential to identify how these variables are associated over time, to provide knowledge for the development of intervention strategies to promote health in pediatric populations. Also, there is a lack of studies examining these associations longitudinally. The aims of the present study were: (1) to investigate the longitudinal relationships between ST, sleep duration, leisure PA, body mass index (BMI), and cardiometabolic risk score (cMetS) in children and adolescents; and (2) to verify scores and prevalence of cMetS risk zones at baseline and follow-up. METHODS: This observational longitudinal study included 331 children and adolescents (aged six to 17 years; girls = 57.7%) from schools in a southern city in Brazil. ST, sleep duration, and leisure PA were evaluated by a self-reported questionnaire. BMI was evaluated using the BMI z-scores (Z_BMI). The cMetS was determined by summing sex- and age-specific z-scores of total cholesterol/high-density lipoprotein cholesterol (HDL-C) ratio, triglycerides, glucose, and systolic blood pressure and dividing it by four. A two-wave cross-lagged model was implemented. RESULTS: ST, sleep duration, and leisure PA were not associated with cMetS after 2-years. However, it was observed that higher ST at baseline was associated with shorter sleep duration at follow-up (B=-0.074; 95%IC=-0.130; -0.012), while higher Z_BMI from baseline associated with higher cMetS of follow-up (B = 0.154; 95%CI = 0.083;0.226). The reciprocal model of relationships indicated that the variance of ST, sleep time, leisure PA, Z_BMI, and cMetS explained approximately 9%, 14%, 10%, 67% and 22%, respectively, of the model. Individual change scores and prevalence indicated that cMetS had individual changes from 2014 to 2016. CONCLUSION: Sleep duration, ST and leisure PA were not associated with cMetS after 2 years. ST showed an inverse association with sleep duration, and Z_BMI was positively associated with cMetS after a 2-year follow-up. Finally, the prevalence of no clustering of risk factors increased after two years. These findings suggest the need to promote healthy lifestyle habits from childhood and considering individual factors that can influence cardiometabolic health in children and adolescents.

Patient outcome quality indicators for older persons in acute care: original development data using interRAI AC-CGA.

BACKGROUND: A range of strategies are available that can improve the outcomes of older persons particularly in relation to basic activities of daily living during and after an acute care (AC) episode. This paper outlines the original development of outcome-oriented quality indicators (QIs) in relation to common geriatric syndromes and function for the care of the frail aged hospitalized in acute general medical wards. METHODS: Design QIs were developed using evidence from literature, expert opinion, field study data and a formal voting process. A systematic literature review of literature identified existing QIs (there were no outcome QIs) and evidence of interventions that improve older persons' outcomes in AC. Preliminary indicators were developed by two expert panels following consideration of the evidence. After analysis of the data from field testing (indicator prevalence, variability across sites), panel meetings refined the QIs prior to a formal voting process. SETTING: Data was collected in nine Australian general medical wards. PARTICIPANTS: Patients aged 70 years and over, consented within 24 h of admission to the AC ward. MEASUREMENTS: The interRAI Acute Care - Comprehensive Geriatric Assessment (interRAI AC-CGA) was administered at admission and discharge; a daily risk assessment in hospital; 28-day phone follow-up and chart audit. RESULTS: Ten outcome QIs were established which focused on common geriatric syndromes and function for the care of the frail aged hospitalized in acute general medical wards. CONCLUSION: Ten outcome QIs were developed. These QIs can be used to identify areas where specific action will lead to improvements in the quality of care delivered to older persons in hospital.

Associations of sleep time, quality of life, and obesity indicators on physical literacy components: a structural equation model.

AIM: To verify the association between ideal sleep time and physical literacy components while also considering multiple mediators, such as quality of life and obesity, using a sample of adolescents. METHODS: This cross-sectional study consisted of 470 adolescents aged 11-17 years from southern Brazil. Sleep time, health-related quality of life, and physical literacy components (i.e., physical education enjoyment, sports participation, sedentary behavior, moderate to vigorous physical activity, sex, and age) were evaluated through self-reported questionnaires. In addition, body mass index (BMI), and waist circumference were determined. The theoretical/statistical support of the structural equation model was evaluated according to fit parameters and strength of association. RESULTS: A direct association was observed between more sleep time and lower levels of obesity. The obesity indicators also had a negative association with HqOL, and HqOL had a positive association with physical literacy. The indirect associations indicated that the ideal sleep time was positively associated with HqOL and physical literacy components, considering the negative mediation effect of obesity. The model explains physical literacy in 31% of the variance (R = 0.31). CONCLUSION: There was an indirect association between ideal sleep duration and quality of life and between both variables with physical literacy. These relationships occur even considering the negative influence of obesity. Therefore, a child who sleeps adequately has a higher likelihood of being physically active, regardless of obesity, potentially enhancing overall quality of life across various domains.

Moderating role of 1-minute abdominal test in the relationship between cardiometabolic risk factors and adiponectin concentration in adolescents.

BACKGROUND: Adiponectin is an anti-inflammatory cytokine secreted by adipose tissue, has been associated with adiposity and cardiometabolic risk, and has controversial results with muscular fitness. The aim of this study was to analyze the interaction of 1-minute abdominal test in the relationship between adiposity, body composition, cardiometabolic risk and adiponectin concentration in adolescents. METHODS: This is a cross-sectional study conducted with 62 adolescents of both sexes, aged 11 to 16 years, approved by the Ethics Committee of Research in Humans (CAEE: 62963916.0.0000.5223). Body mass, height, abdominal circumference (AC), waist circumference (WC), fat mass (FM), fat-free mass (FFM), high density lipoprotein (HDL-c), low density lipoprotein (LDL-c), triglycerides (TG), adiponectin, systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean blood pressure (MBP), 1-minute abdominal test (ABD) were measured. Body mass index (BMI), z-score BMI (BMI-z), triponderal mass index (TMI), and waist-to-height ratio (WHtR) were calculated. The macro PROCESS for SPSS v.24.0 was used for moderation analyses, with linear regression models. RESULTS: Inverse interactions were found for adiposity (BMI, BMI-z, TMI, AC, WC, WHtR), body composition (FM, FFM) and CMRF (SBP, DBP, MBP, TG) versus 1-minute abdominal test with adiponectin concentration, demonstrating that abdominal test is a moderator in these relationships. CONCLUSION: We conclude that 1-minute abdominal test may play an important role in the relationship between obesity and cardiometabolic risk. We found that muscular fitness can confer a protective effect on adolescents with high levels of abdominal test.

The Longitudinal Association of Cardiorespiratory Fitness and Adiposity With Clustered Cardiometabolic Risk: A Mediation Analysis.

PURPOSE: Previous literature has demonstrated the mediating role of adiposity in the association between cardiorespiratory fitness (CRF) and cardiometabolic risk as well as the potential role of CRF in attenuating the adverse consequences associated with excess weight. This study aimed to evaluate the mediating role of CRF and adiposity in the possible association with cardiometabolic risk. METHOD: Observational 3-year longitudinal study that included 420 children and adolescents (10.50 [2.05] y of age at baseline; 56.2% girls). Body mass index (BMI) was calculated, and CRF was evaluated using field assessments. A clustered cardiometabolic risk score (cMetS) was calculated from glucose, systolic blood pressure, total cholesterol/high-density lipoprotein cholesterol ratio, and triglycerides z scores. Analyses evaluated the mediating role of BMI in the association between CRF and cMetS as well as whether CRF mediated the association between BMI and cMetS. RESULTS: BMI at baseline was directly associated with the cMetS at follow-up (0.102; 95% confidence interval, 0.020 to 0.181), independently of CRF, whereas CRF was only indirectly associated with cMetS at follow-up through BMI (-0.036; 95% confidence interval, -0.070 to -0.009), meaning that the association between CRF and cMetS was explained via the mediation role of BMI. CONCLUSIONS: BMI presented direct association with cMetS, whereas CRF exhibited indirect association with cMetS mediated via BMI.

Reliability, reproducibility, and feasibility of youth activity profile (YAP) questionnaire in Chilean children and adolescents.

This study aimed to evaluate the reliability, reproducibility, and feasibility of the Youth Activity Profile Questionnaire (YAP-SL) in the Chilean version (YAP-C) in a sample of children and adolescents. This cross-sectional study included 160 youth, 59 children (5-11 years old), and 101 adolescents (12-17 years old) from the city of Viña del Mar (Chile). The YAP-SL is a 15-item self-report instrument which was administered twice at an interval of 7 days apart. This questionnaire was designed to capture physical activity (PA) and sedentary behaviour in youths in the last week, categorizing them into three domains: PA at school, PA out-of-school, and sedentary habits. Cronbach's α coefficients were calculated to evaluate the internal consistency (reliability), and the reproducibility was determined by test-retest and Kendall's tau b coefficients. Concerning the total YAP-C score, results indicated moderate-to-high reliability in the total sample (0.71), boys (0.76) and girls (0.66), as well as for children (0.73) and adolescents (0.70). The results also revealed variations in reliability and reproducibility across the three domains. In conclusion, the YAP-SL questionnaire presents moderate-to-high reliability in Chilean children and adolescents. However, the reliability and consistency of the YAP varied across the domains.

WEB OF TRANSFORMATIONS: impact of multicomponent intervention on the relationship between sociodemographic indicators, changes in body composition, cardiorespiratory fitness and biochemical markers in adolescents with overweight and obesity.

The study aims to analyze the relationships between changes after multicomponent intervention in sociodemographic indicators, body composition, cardiorespiratory fitness and biochemical markers in overweight/obese adolescents. Quasi-experimental study with 33 overweight/obese adolescents (17 in the intervention group (IG) and 16 in the control group (16)), in which the GI participated in the multicomponent intervention for 24 weeks. Sociodemographic indicators, body composition, cardiorespiratory fitness and biochemical markers were evaluated. Network analysis was performed using JASP software. In GI, the reduction in %BF proved to be the variable with greater connectivity and strength in the network compared to the control network. Changes in %BF were related to changes in ACR, BMI and leptin. It is concluded that the reduction in %BF is the most important variable in network relationships after the intervention, suggesting that the greater the reduction in %BF, the greater the effect on variables such as BMI, ACR and leptina.

Exploring cardiovascular health in children: the influence of Hemoglobin-to-Platelet ratio in contrasting rural and urban communities.

Understanding the associations and possible mechanisms between Cardiorespiratory Fitness (CRF) and residential location is an important focus of public health research. This is a cross-sectional study carried out with 2250 students (6-17 years), from southern Brazil. In addition to age, sex, and body size measurements, we also recorded hemoglobin and platelet count measurements using venous blood samples (10 ml). The CRF was measured using the 6-minute run/walk test, with predictors explored via allometry. Results identified a novel and independent association between the hemoglobin-to-platelet count ratio and children's CRF, after controlling for confounders. We also provide evidence of a possible mechanism for this association, having identified reduced measures of hemoglobin and increased platelet counts observed in children living in urban (vs rural) areas. These results suggest the need for more effective public health practices and policies addressing the built enviroment´s health effects in Brazil and potentially other congested ciries.

Fitness and fatness in children and adolescents: investigating their role in the association between physical activity and cardiometabolic health.

To verify the role of the combination of fitness and fatness in the relationship between physical activity (PA) and cardiometabolic risk in children and adolescents. This is a cross-sectional study performed with 2786 children and adolescents (6 to 17 years). Fitness was determined by the cardiorespiratory fitness (CRF) six-minute walking and running test. Waist circumference (WC) was considered a fatness indicator. A selfreported questionnaire was used to determine PA practice, whereas the clustered cardiometabolic risk score (cMetS) was calculated by summing z-scores of triglycerides, total cholesterol/HDL-C ratio, systolic blood pressure, glucose, and WC. Considering the combination of CRF (fitness) and WC (fatness), the following phenotypes were created: Fit/Unfat, Fit/Fat, Unfit/Unfat and Unfit/Fat. Moderation analyses were tested using linear regression models. Significant interactions were found between PA and Unfit/Fat category (ß = -0.001; p = 0.001) only for adolescents. The interaction observed in the Unfit/Fat phenotype indicated that adolescents who practise PA for 330 minutes per week presented lower cMetS compared to those who do not practise or practise for 60 minutes respectively. The combination of fitness and fatness moderates the relationship between PA and cardiometabolic risk, suggesting that adolescents, particularly those who are less fit and present high adiposity, should be encouraged to engage in regular PA to improve their metabolic health.

Sedentary time play a moderator role in the relationship between physical fitness and brain-derived neurotrophic factor in children. A pilot study.

Aim: Despite some advances, there are many controversies concerning brain-derived neurotrophic factor (BDNF) and its relationships with variables related to physical fitness and sedentary time, especially in children. The aim of the study was to explore the moderating role of sedentary time on the association between physical fitness and BDNF. Therefore, this study will add to the perspective of understanding how much time children may spend being sedentary with no deleterious influence on the positive association between physical fitness and BDNF. Methods: This cross-sectional study included 44 children aged between 6 and 11 years (9.02 ± 1.43) from a public school in Porto Alegre, Brazil. Cardiorespiratory fitness (CRF) was determined by the 6-min walk/run test, and muscular strength was determined through the lower limb strength test (LLS). Sedentary time was assessed through accelerometers, and blood samples were collected to determine serum BDNF levels (z score). Moderation analysis was performed using the PROCESS macro adjusted for sex, age, somatic maturation, waist circumference, and socioeconomic level. Results: Sedentary time moderates the relationship between CRF and BDNF, such that children should spend less than 511 minutes per day sedentary to achieve the benefits of CRF in BDNF concentrations. Conclusion: Sedentary time plays a significant moderating role in the relationship between CRF and BDNF. Therefore, to promote brain health in children, both increasing physical fitness and reducing sedentary time might be encouraged.

A network analysis involving mental difficulties, cognition, physical fitness, 24-hour movement components, fatness, and sociodemographic factors in children.

Background: Evidence supports the beneficial linear influence of diverse lifestyle behaviors on brain health since childhood; however, multiple behaviors -and not only one-simultaneously affect such outcomes. Therefore, the aim was to explore the multivariate relationship through a network analysis among mental difficulty and cognitive function with physical fitness (PF), 24-h movement components, fatness, and sociodemographic factors in children. Methods: Cross-sectional study involved 226 children (52.2 % boys) aged between six and 11 years. Mental difficulties were evaluated through the Strengths and Difficulties Questionnaire and cognitive function by the Raven's Colored Progressive Matrices Test. The body mass index and PF were assessed according to the procedures suggested by the Proesp-Br, while moderate-to vigorous-intensity physical activity (MVPA) using accelerometry. The socioeconomic level, sleep, and screen time were evaluated by questionnaires. A network analysis was carried out to evaluate the associations among variables and establish centrality measures. Results: Age and PF moderated the negative relationship between cognitive function and MVPA. Furthermore, the direct and inverse relationship between cognitive function and mental difficulties appears to be affected by the 24-h movement components. Finally, age, PF, and screen time are the nodes with higher values of expected influence, indicating more sensitivity to interventions for decreasing mental difficulty and improving cognitive function. Conclusion: Mental health and cognitive function were moderated by the multivariate interaction among age, PF, and the three 24-h movement components. Nonetheless, centrality measures from the network analysis suggest that PF, MVPA, and screen time are crucial nodes in order to implement future interventions.

Body fat percentage, cardiorespiratory fitness and arterial blood pressure in children and adolescents: a longitudinal analysis.

BACKGROUND: A better understanding of how cardiorespiratory fitness (CRF) and adiposity interact to associate with arterial blood pressure over time remains inconclusive. Thus, the aim of the present study was to examine whether changes in CRF moderates the association between body fat percentage (BF%) and arterial blood pressure in children and adolescents. METHODS: This is an observational longitudinal study with 407 children and adolescents aged 8-17 years followed-up for three years from a city in Southern Brazil. Participants were evaluated in 2011 and 2014. CRF was measured by validated field-based tests following the Projeto Esporte Brazil protocols and peak oxygen uptake (VO2peak) was estimated. BF% was determined by the measures of tricipital and subscapular skinfolds using equations according to sex. Systolic and diastolic blood pressure (SBP, DBP) were measured with a sphygmomanometer according to standard procedures. Moderation analyses included multiple linear regression models adjusted for sex, age, pubertal status, height, socioeconomic level, skin color, and the arterial blood pressure variable itself at baseline. RESULTS: It was observed a significant inverse association between VO2peak at baseline with SBP (ß = - 0.646 CI95% = - 0.976 - 0.316) and DBP (ß = - 0.649 CI95% = - 0.923 - 0.375) at follow-up and a positive association between BF% at baseline with SBP (ß = 0.274; CI95% = 0.094 0.455) and DBP (ß = 0.301; CI95% = 0.150 0.453) at follow-up. In addition, results indicated a significant interaction term between changes in VO2peak and BF% at baseline with both SBP (p = 0.034) and DBP at follow-up (p = 0.011), indicating that an increase of at least 0.35 mL/kg/min and 1.78 mL/kg/min in VO2peak attenuated the positive relationship between BF% with SBP and DBP. CONCLUSION: CRF moderates the relationship between BF% and SBP and DBP in children and adolescents.

What is the role of cardiorespiratory fitness and sedentary behavior in relationship between the genetic predisposition to obesity and cardiometabolic risk score?

BACKGROUND: Genetic factors along with inadequate lifestyle habits are associated with the development of cardiometabolic alterations. Thus, the present study aimed to examine the role of sedentary behavior on the relationship between rs9939609 polymorphism (fat mass and obesity-associated gene-FTO) and cardiometabolic risk score according to cardiorespiratory fitness (CRF) levels in children and adolescents. METHODS: A cross-sectional study with 1215 children and adolescents (692 girls), aged between 6 and 17 years. Screen time as a marker of sedentary behavior was evaluated through a self-reported questionnaire and CRF was estimated using the 6-min walking and running test. The genotyping of the FTO rs9939609 polymorphism was performed using a real-time polymerase chain reaction. Clustered cardiometabolic risk score (cMetS) was calculated by summing z-scores of total cholesterol/high-density lipoprotein cholesterol ratio, triglycerides, glucose, systolic blood pressure, and waist circumference, and dividing it by five. Moderation analyses were tested using multiple linear regression models. RESULTS: The coefficient of the interaction term of FTO (rs9939609) and screen time indicated that screen time was a significant moderator on the relationship between FTO rs9939609 polymorphism and cMetS (p = 0.047) in children and adolescents classified with low CRF (ß = 0.001; 95% CI = 0.001; 0.002). It was observed a significant association between genotype risk (AA) of FTO polymorphism and cMetS, in participants that spent more than 378 min a day in front of screen-based devices (ß = 0.203; 95% CI = 0.000; 0.405). No interaction term was found for those with high CRF. CONCLUSIONS: High sedentary behavior seems to influence the relationship between genetic predisposition to obesity and cardiometabolic risk factors in children and adolescents with low CRF.

Cardiovascular health behavior and blood pressure in adolescents: A longitudinal analysis.

BACKGROUND: The ideal cardiovascular health behaviors (ICHB) have been associated with a subsequent positive health status in adults. However, evidence regarding blood pressure (BP) and ICHB in adolescents is scarce. The aim of this prospective cohort was to evaluate the impact of accumulation of ICHB on BP values in adolescents over two years. METHODS: This is a longitudinal analysis with 445 adolescents (232 girls) aged 12-18 years old. Resting blood pressure was measured at baseline and 2 years later, and ICHBs at baseline according to standard procedures. Based on the American Heart Association definition, the ICHB index was defined as a sum of meeting the ICHBs (from 0 to 4, where 4 would be the healthiest profile of all ICHBs) for a healthy diet, physical activity, smoking status and body mass index. RESULTS: Adjusted means values (ANCOVA) of BP parameters through achievement of a greater number of (between 1-4) the ICHBs (adjusting for potential confounders, age, sex, pubertal stage and socioeconomic status) showed that, as increase the number of ICHB accumulated as a lower the BP levels [ICHB and SBP (F3.435) = 4.501, p = 0.004), DBP (F(3.435) = 2.725, p = 0.044), pulse pressure (F(3.435) = 4.004, p = 0.008), and rate pressure product (F(3.435) = 2.866, p = 0.036)] over two years. CONCLUSION: A lower number of ICHB (smoking status, body mass index, physical activity, and diet) during adolescence play a key role on blood pressure over two years. A higher number of ICHB is seen to be associated with a lower risk of short-term, hypertension.

Relationship between rs9939609 FTO polymorphism with waist circumference and body fat is moderated by ponderal index at birth in youth.

OBJECTIVE: The goal of this study was to analyze whether the relationship between the rs9939609 polymorphism of the fat mass and obesity-associated gene (FTO) with nutritional status is moderated by the ponderal index (PI) at birth in children and adolescents. METHODS: A cross-sectional study evaluated 382 schoolchildren aged 6-17 years. Anthropometric variables such as waist circumference (WC), body mass index (BMI) and body fat percentage (BF%) were used to assess nutritional status. Weight and height at birth were used for the PI calculation, which was divided into tertiles (lower, middle and upper). To compare the continuous variables between genotypes of the rs9939609 polymorphism, a recessive model (TT/AT vs. AA) and covariance analysis (ANCOVA) were used. RESULTS: The AA genotype of the rs9939609 polymorphism was associated with higher WC in schoolchildren born with lower PI (ß = 4.40; p = .048). However, for BF%, the genotype association was found in the upper PI tertile (ß = 7.35; p = .040). CONCLUSION: The relationship between WC and BF% with rs9939609 polymorphism (FTO) seems to be moderated by PI at birth. This is an important insight, since the data for intrauterine growth, genetic factors and the presence of obesity in children and adolescents are still contradictory.

Evaluation of IMproving Palliative care Education and Training Using Simulation in Dementia (IMPETUS-D) a staff simulation training intervention to improve palliative care of people with advanced dementia living in nursing homes: a cluster randomised controlled trial.

BACKGROUND: People with dementia have unique palliative and end-of-life needs. However, access to quality palliative and end-of-life care for people with dementia living in nursing homes is often suboptimal. There is a recognised need for nursing home staff training in dementia-specific palliative care to equip them with knowledge and skills to deliver high quality care. OBJECTIVE: The primary aim was to evaluate the effectiveness of a simulation training intervention (IMPETUS-D) aimed at nursing home staff on reducing unplanned transfers to hospital and/or deaths in hospital among residents living with dementia. DESIGN: Cluster randomised controlled trial of nursing homes with process evaluation conducted alongside. SUBJECTS & SETTING: One thousand three hundred four people with dementia living in 24 nursing homes (12 intervention/12 control) in three Australian cities, their families and direct care staff. METHODS: Randomisation was conducted at the level of the nursing home (cluster). The allocation sequence was generated by an independent statistician using a computer-generated allocation sequence. Staff from intervention nursing homes had access to the IMPETUS-D training intervention, and staff from control nursing homes had access to usual training opportunities. The predicted primary outcome measure was a 20% reduction in the proportion of people with dementia who had an unplanned transfer to hospital and/or death in hospital at 6-months follow-up in the intervention nursing homes compared to the control nursing homes. RESULTS: At 6-months follow-up, 128 (21.1%) people with dementia from the intervention group had an unplanned transfer or death in hospital compared to 132 (19.0%) residents from the control group; odds ratio 1.14 (95% CI, 0.82-1.59). There were suboptimal levels of staff participation in the training intervention and several barriers to participation identified. CONCLUSION: This study of a dementia-specific palliative care staff training intervention found no difference in the proportion of residents with dementia who had an unplanned hospital transfer. Implementation of the intervention was challenging and likely did not achieve adequate staff coverage to improve staff practice or resident outcomes. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12618002012257 . Registered 14 December 2018.

Family history of arterial hypertension and central adiposity: impact on blood pressure in schoolchildren.

BACKGROUND: A family history of arterial hypertension is an important risk factor for arterial hypertension. This study aimed to verify the mediating role of high central adiposity in the relationship between family history of arterial hypertension and blood pressure in schoolchildren. METHODS: Cross-sectional study with 118 schoolchildren of both sexes aged between 11 and 17 years. Weight, height, waist circumference and body mass index z score were verified. Somatic maturation was predicted by age for peak growth velocity. The family history of arterial hypertension was verified and defined as hypertensive schoolchildren with systolic blood pressure or diastolic blood pressure. Mediation analysis was used with linear regression models applied by PROCESS macro for SPSS (version 22.0), with significance p < 0.05. RESULTS: It was observed that 34.7% of the students have family history of arterial hypertension, 36% of the girls and 44.2% of the boys have arterial hypertension. In girls, the relationship between waist circumference and systolic blood pressure was direct (ß = 0.535 p = 0.005), and those with a family history of arterial hypertension and who had a waist circumference greater than those without a family history of arterial hypertension was significant (ß = -5,437 p = 0.009). Likewise, the relationship between family history of arterial hypertension and systolic blood pressure was attenuated when waist circumference was included in the model (ß = -5.544; p = 0.103), indicating waist circumference as a mediator with an influence percentage of 19%. For boys, waist circumference is not a mediator of the relationship between family history of arterial hypertension and blood pressure. CONCLUSIONS: Elevated central adiposity was a mediator of the relationship between family history of arterial hypertension and high blood pressure in girls, indicating the importance of family health strategies in the prevention and management of arterial hypertension in children and adolescents.

Physical Exercise and Brain-Derived Neurotrophic Factor Concentration in Children and Adolescents: A Systematic Review With Meta-Analysis.

PURPOSE: To systematically review the literature on the relationship between physical activity and the effect of physical training on brain-derived neurotrophic factor (BDNF) concentrations in children and adolescents. METHODS: The searches were conducted in the databases: PubMed, ScienceDirect, Web of Science, Scopus, SPORTDiscus, Latin American and Caribbean Center for Science Information of Health, and SciELO. All original studies that analyzed the relationship between the practice of physical activity and the effect of physical training on plasma and serum BDNF concentrations in children and adolescents were included. The standardized mean difference (SMD), correlation coefficient (r), and 95% confidence interval were calculated. RESULTS: Eleven studies were selected, totaling 1424 children and adolescents. Cross-sectional studies indicated a significant inverse relationship between physical activity and BDNF concentrations in boys (r = -.117 [-.222, -.009]; P = .033), but not in girls (P = .230). Adolescent athletes tend to have lower serum, but higher plasma BDNF concentrations than sedentary ones (SMD = -0.677 [0.188]; P < .001). An increase in serum BDNF was observed after physical training (SMD = 0.437 [0.183]; P = .017), with no effect in the control group (SMD = 0.235 [0.193]; P = .225). CONCLUSIONS: Adolescent athletes tend to show lower serum, but higher plasma BDNF concentrations compared with sedentary individuals. Furthermore, physical training seems to increase serum BDNF concentrations in sedentary adolescents to a small extent.

Identifying the ideal "body shape" associated with athletic performance using three dimensional (height, body mass and waist) allometry.

The purpose of the current study was to identify the most appropriate "body shape" associated with six athletic performance (AP) tests, using three-dimensional allometry (height (HT), body mass (M), and waist circumference (WC)), in a sample of Brazilian children and adolescents. The sample consisted of 11018 Brazilian children/adolescents (5147 boys) aged 7-17 years. The 6 AP tests were, a 20 m sprint test, an agility test, a 6/9 minute walk/run endurance test, an upper body strength test, an abdominal muscular endurance test, and a lower limb strength test. The "three-dimensional" allometric model was, AP= a⋅ Mk1⋅ HTk2⋅ WCk3. Results indicated that two of the three body-size dimensions (HT and WC) were consistently associated with all six athletic performance tests. These were a positive HT exponent/term together with a negative WC exponent/term, confirming that being taller benefited all six performance tests but excess WC was always detrimental. The contribution of M depended on whether the athletic performance required the children/adolescent to perform the exercise/test in a "weight-baring" protocol, i.e. having to perform the test carrying their own body weight or not. In conclusion, three-dimensional allometry provides new insights into what constitutes the "ideal" athletic shape associated with children/adolescents.

Integrated role of lifestyle habits in cardiometabolic risk factors according to sex in adolescents.

BACKGROUND: A healthy lifestyle should be adopted by young people to maintain cardiometabolic health. AIM: To verify the prevalence and the integrated role of lifestyle habits in cardiometabolic risk factors according to sex in adolescents. SUBJECTS AND METHODS: Cross-sectional study developed with 1502 adolescents, aged 10-17 years. Lifestyle habits included physical activity, screen time and sleep duration evaluated through a questionnaire. Cardiometabolic risk score (CMRS) was calculated by summing z-scores, divided by 6. For statistical analyses, multivariable binary and multinomial logistic regression models were used. RESULTS: 80.7% of the boys classified with adverse CMRS presented physical inactivity, compared to normal CMRS. In girls, 42.6% showed inadequate sleep compared to normal CMRS. Boys classified as inactive showed higher odds for obesity, as well as altered triglycerides (TGs), and systolic blood pressure, risk for cardiorespiratory fitness (CRF), high waist circumference, and CMRS, compared to the active. A prolonged screen time increased the odds for altered glucose and decreased the odds for altered TGs. In girls, inadequate sleep duration presented higher odds for overweight, obesity, risk for CRF, and high CMRS, compared to adequate sleep. CONCLUSION: Physical activity for boys and sleep duration for girls are important to maintain healthy metabolic health amongst youth.