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.

Moderation of Physical Activity between Cardiometabolic Risk and Adiponectin in Adolescents.

The aims of the study were to examine the moderating role of physical activity in the relationship between cardiometabolic risk factors and adiponectin concentration in adolescents. This is a cross-sectional study conducted with 96 adolescents of both sexes, between 11 and 17 years old. Body mass, height, fat mass (FM), fat-free mass, systolic blood pressure, diastolic blood pressure, high density lipoprotein, low density lipoprotein (LDL-c), triglycerides, insulin, adiponectin, C-reactive protein, and level of physical activity (energy expenditure questionnaire) were measured. Body mass index (BMI), triponderal mass index (TMI), homeostasis model to assessment insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI) were calculated. Macro-PROCESS for SPSS was used for moderation analyses. Direct interactions were found for BMI, TMI, FM, insulin, and HOMA-IR and inverse for LDL-c, and QUICKI. Protection against cardiometabolic risk was found when the PA-coeff was completed above 1.57 coeff (BMI), 1.62 coeff (TMI), 1.55 coeff (FM), 1.41 coeff (LDL-c)1.60 coeff (insulin), 1.59 coeff (HOMA-IR) and 1.35 coeff (QUICKI). We conclude that physical activity was a moderator in the relationship with adiposity, insulin resistance and sensitivity, LDL-c, and adiponectin. In this context, we evidenced a relevant clinical impact on the health of adolescents, demonstrating the interaction between anthropometrics variables and physical activity.

Adolescents who practice physical activity have adequate food choices, regardless of the level of somatic maturation and adiposity.

OBJECTIVES: Regular physical activity and adequate food are part of a healthy lifestyle for the maintenance of physical and metabolic health. To verify the moderating role of physical activity (PA) in the relationship between dietary patterns and body adiposity in adolescents, according to somatic maturation. METHODS: Study with cross-sectional design, sample of 336 adolescents of both sexes, aged between 11 and 17 years. Body mass, height, and waist circumference (WC) were evaluated. Body mass index (BMI), BMI z-score (BMI-z), waist-to-height ratio (WHtR), and somatic maturation by peak height velocity (PHV) were calculated. The level of PA was measured by the International Physical Activity Questionnaire and dietary pattern by the Food Frequency Questionnaire ELSA - Brazil (short version). Moderation analyzes were tested using multiple linear regression models, by PROCESS macro for SPSS. RESULTS: An inverse interaction of PA was observed in the relationship between food consumption factor 5 (ultra-processed foods category) and WC in boys categorized as pre-pubertal and pubertal PHV (ß=-5.344; CI95 % -10.108 -0.580; p=0.028). For girls, no interaction was observed in any of the models analyzed. CONCLUSIONS: It was observed that the level of PA can influence food choices in prepubertal and pubertal boys, since the active boys showed better dietary pattern and lower central adiposity. Therefore, the findings reinforce the need to encourage the regular practice of physical activities from an early age, mainly aimed at preventing obesity in children and adolescents.

Effects and individual response of continuous and interval training on adiponectin concentration, cardiometabolic risk factors, and physical fitness in overweight adolescents.

This study aimed to evaluate the effect and individual responsiveness after 12 weeks of high-intensity interval training (HIIT) and moderate-intensity of continuous training (MICT) on adiponectin, cardiometabolic risk factors and physical fitness in overweight adolescents. This study was participated by 52 adolescents, both sexes, 11 and 16 years old, separated into HIIT (n = 13), MICT (n = 15), and control group (CG, n = 24). Body mass, height, waist circumference (WC), fat mass (FM), fat-free mass (FFM), blood pressure, high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c), triglycerides, glucose, insulin, adiponectin, and C-reactive protein (CRP) were evaluated. Body mass index z-score (BMI-z), waist-to-height ratio (WHtR), insulin resistance, and insulin sensitivity were calculated. Resting heart rate (HRrest), peak oxygen consumption (VO2peak), right handgrip strength (HGS-right), left handgrip strength (HGS-left), and abdominal resistance (ABD) was evaluated. HIIT session lasted around 35 min and MICT of 60 min of exercises on stationary bicycle, three times a weekday for 12 weeks. ANOVA, effect size, and prevalence of responders were used for statistical analysis. HIIT reduced BMI-z, WHtR, LDL-c, and CRP, while increased of physical fitness. MICT reduced HDL-c, while increased of physical fitness. CG reduced FM, HDL-c, and CRP, while increased FFM and HRrest. Frequencies of respondents in HIIT were observed for CRP, VO2peak, HGS-right, and HGS-left. Frequencies of respondents in MICT were observed for CRP and HGS-right. Frequencies of no-respondents in CG were observed for WC, WHtR, CRP, HRrest, and ABD.  Conclusion: Interventions with exercises were effective to adiposity, metabolic health, and physical fitness improvements. Individual responses were observed in inflammatory process and physical fitness, important changes in overweight adolescent's therapy.  Trial registration number and date of registration: This study was registered with the Brazilian Registry of Clinical Trials (REBEC), the number RBR-6343y7, date of registration May 3, 2017. What is Known: • Effect of regular physical exercise positively affects overweight, comorbidities, and metabolic diseases, recommended mainly for children and adolescents. What is New: • Due to the great inter-individual variability, the same stimulus can provide different responses; adolescents who benefit from the stimulus are considered responsive. • Intervention of HIIT and MICT did not alter the concentrations of adiponectin; however, the adolescents presented responsiveness to the inflammatory process and physical fitness.

Prediction equations for maximal heart rate in obese and nonobese children and adolescents: a systematic review and meta-analysis.

OBJECTIVE: The aim of this study was to analyze which equation best estimates maximal heart rate (HRmax) for the pediatric population according to body mass. DATA SOURCE: We performed a meta-analysis (PROSPERO No. CRD42020190196) of cross-sectional studies that aimed to validate or develop HRmax equations and that had children and adolescents as samples. The search was conducted in Scopus, Science Direct, Web of Science, PubMed, and Biblioteca Virtual em Saúde with the descriptors "prediction or equation," "maximal heart rate," "maximum heart rate," "determination of heart rate," children, and adolescent. The TRIPOD Statement tool was used to assess the methodological quality and the relevant data were extracted for analysis. The meta-analysis was conducted in the Comprehensive Meta-Analysis, adopting p<0.05 and a 95% confidence interval (CI). DATA SYNTHESIS: In total, 11 studies were selected, of which 3 developed predictive equations, 10 performed external validity of the preexisting models, and 1 incremented values related to equations already developed. The results of the methodological quality analysis showed a moderate rating in most studies. The 164 + (0.270 × HRres) - (0.155 × body mass) + (1.1 × METs) + (0.258 × body fat percent) (r=0.500, 95%CI 0.426-0.567, p<0.001) and 166.7+ (0.46 × HRres) + (1.16 × maturation) (r=0.540, 95%CI 0.313-0.708, p<0.001) equations presented stronger correlations with measured HRmax in nonobese adolescents. The predictive model developed by 208 - (0.7 × age) showed a greater accuracy among the possible models for analysis (SDM=-0.183, 95%CI -0.787 to -0.422, p=0.554). No specific predictive equation was found for obese adolescents. CONCLUSIONS: Future research should explore new possibilities for developing predictive equations for this population as a tool to control exercise intensity in the therapeutic management of childhood and adolescent obesity.

Prediction equations for maximal heart rate in obese and nonobese children and adolescents: a systematic review and meta-analysis / Equações preditivas da frequência cardíaca máxima em crianças e adolescentes obesos e não obesos: uma revisão sistemática e metanálise

Abstract Objective: The aim of this study was to analyze which equation best estimates maximal heart rate (HRmax) for the pediatric population according to body mass. Data source: We performed a meta-analysis (PROSPERO No. CRD42020190196) of cross-sectional studies that aimed to validate or develop HRmax equations and that had children and adolescents as samples. The search was conducted in Scopus, Science Direct, Web of Science, PubMed, and Biblioteca Virtual em Saúde with the descriptors "prediction or equation," "maximal heart rate," "maximum heart rate," "determination of heart rate," children, and adolescent. The TRIPOD Statement tool was used to assess the methodological quality and the relevant data were extracted for analysis. The meta-analysis was conducted in the Comprehensive Meta-Analysis, adopting p<0.05 and a 95% confidence interval (CI). Data synthesis: In total, 11 studies were selected, of which 3 developed predictive equations, 10 performed external validity of the preexisting models, and 1 incremented values related to equations already developed. The results of the methodological quality analysis showed a moderate rating in most studies. The 164 + (0.270 × HRres) - (0.155 × body mass) + (1.1 × METs) + (0.258 × body fat percent) (r=0.500, 95%CI 0.426-0.567, p<0.001) and 166.7+ (0.46 × HRres) + (1.16 × maturation) (r=0.540, 95%CI 0.313-0.708, p<0.001) equations presented stronger correlations with measured HRmax in nonobese adolescents. The predictive model developed by 208 - (0.7 × age) showed a greater accuracy among the possible models for analysis (SDM=-0.183, 95%CI -0.787 to -0.422, p=0.554). No specific predictive equation was found for obese adolescents. Conclusions: Future research should explore new possibilities for developing predictive equations for this population as a tool to control exercise intensity in the therapeutic management of childhood and adolescent obesity.

Resumo Objetivo: Analisar qual equação melhor estima a frequência cardíaca máxima (FCmáx) na população pediátrica conforme a massa corporal. Fontes de dados: Foi realizada uma metanálise (PROSPERO no CRD42020190196) de estudos transversais que visavam validar ou desenvolver equações da FCmáx para crianças e adolescentes. As bases de dados foram Scopus, Science Direct, Web of Science, PubMed e Biblioteca Virtual em Saúde. Utilizaram-se os descritores "prediction or equation", "maximal heart rate", "maximum heart rate", "determination of heart rate", "children" e "adolescents". A ferramenta TRIPOD Statement foi utilizada para avaliar a qualidade metodológica e os dados relevantes foram extraídos para análise. A metanálise foi conduzida no Comprehensive Meta-Analysis, adotando-se valor de p<0,05 e intervalo de confiança de 95%. Síntese dos dados: Foram selecionados 11 estudos, dos quais três desenvolveram equações preditivas, dez realizaram a validade externa de modelos preexistentes e um a incrementação de valores relacionados com equações já desenvolvidas. Em sua maioria, os estudos foram classificados com qualidade moderada. As equações 164 + (0.270 × FCrep) - (0.155 × massa corporal) + (1.1 × METs) + (0.258 × percentual de gordura) (2017) (r=0,500; p<0,001) e 166.7+ (0.46 × FCrep + (1.16 × maturação) (r=0,540; p<0,001) apresentaram correlações mais fortes com a FCmáx medida em adolescentes não obesos. O modelo de 208 - (0.7 × idade) mostrou a maior precisão entre os modelos possíveis para análise (SDM=-0,183; p=0,554). Não foi encontrada nenhuma equação preditiva específica para adolescentes obesos. Conclusões: Pesquisas futuras devem explorar novas possibilidades de desenvolvimento de equações preditivas para essa população, uma vez que elas são uma ferramenta para controlar a intensidade do exercício na gestão terapêutica da obesidade infantil e do adolescente.

Predicting Cardiorespiratory Fitness Using the 20-m Shuttle Run Test: New Insights Using Nonlinear Allometry.

PURPOSE: Recently, doubts have been raised concerning the validity of the 20-m shuttle run test (20mSRT) to predict cardiorespiratory fitness (CRF) in youth. Despite these doubts, authors continue to provide powerful evidence that CRF can be predicted reliably using the 20mSRT albeit using contrasting models. Therefore, we aimed to compare a new linear model with an alternative allometric model to predict CRF (peak oxygen uptake, V˙O2peak) using the 20mSRT. METHODS: The study included 148 adolescents (43% girls) age 13.37 ± 1.84 yr. Adolescents were randomly assigned to validation (n = 91) and cross-validation (n = 57) groups. V˙O2peak was measured using a gas analyzer in both maximal exercise tests in the laboratory and the 20mSRT. Multiple linear regression methods were applied to develop the linear models using the 20mSRT (laps), body mass index, and body fat percentage. Alternative allometric models were also proposed/fitted using the 20mSRT (laps), height, and body mass. RESULTS: The criterion validity values of both the linear and the allomeric models were found to be acceptable, with R2 = 82.5% and 82.7% respectively, providing reassuring evidence that the 20mSRT can be used with confidence to predict CRF. However, the allometric model identified a height-to-mass ratio, not dissimilar to the inverse body mass index (known to be a measure of leanness), to be associated with CRF. The allometric model also revealed that the rise in energy cost (V˙O2peak) with increasing laps was exponential. This will more accurately reflect the nonlinear rise in energy demand of shuttle running as the test progresses to exhaustion. CONCLUSIONS: These observations provided powerful evidence that allometric models are more than satisfactory in terms of both criterion and construct validity when predicting CRF (V˙O2peak) using the 20mSRT.

Validation of equations to estimate the peak oxygen uptake in adolescents from 20 metres shuttle run test.

This study aimed to develop new prediction models from directly determined peak of oxygen uptake (VO2peak) in adolescents using 20-metre shuttle run test (20 m-SR) and to compare the new models with previously published equations. This study included 148 adolescents (43% girls), aged 13.37 ± 1.84 years old. Adolescents were randomly assigned to validation (n = 91) and cross-validation (n = 57) groups. VO2peak was measured using a gas analyser in both maximal exercise tests in the laboratory as well as by 20 m-SR. The multiple linear regression method was applied to develop the models using BMI, BMI-z score and body fat percentage (%FM). The proposed models presented better predictive performance (R2 = 75.6% to 78.9%) and a lower absolute percentage error (%error = 10.51 to 11.78%) than the previously published equations (R2 = 38.8% to 69.1%; %error = 13.13% to 21.54%). The Model with BMI-z was the best fit equation in girls, and the model with BMI-z and %FM in boys. Therefore, it is recommended that the equations developed in the present study be used in future research and projects in the school environment to estimate VO2peak in adolescents by the 20 m-SR test.

Association between physical activity, cardiometabolic risk factors and vitamin D in children and adolescents: a systematic review / Associação entre atividade física, fatores de risco cardiometabólico e vitamina D em crianças e adolescentes: uma revisão sistemática

This systematic review aimed to synthesize evidence of cross-sectional studies on the associations between physical activity, cardiometabolic risk factors and vitamin D concentrations in children and adolescents. The search was performed in PubMed, SciELO, LILACS, Scopus, MEDLINE and SPORTDiscus. Cardiometabolic risk factors included obesity, insulin resistance, systemic arterial hypertension and unfavorable changes in the lipid profile (low levels of high-density lipoprotein, el-evated low-density lipoprotein and triglycerides). Cross-sectional design studies published between 2007 and 2019 were included whether they evaluated the relationship between vitamin D and phys-ical activity and/or vitamin D and cardiometabolic risk factors. Fourteen studies were selected, in-volving 8340 children and adolescents. The main results found were a significant inverse relationship between vitamin D levels and cardiometabolic risk factors. All studies (n = 8) that tested association between physical activity and 25-hydroxyvitamin D (25 (OH) D) concentrations showed a signif-icant and direct relationship between them. In addition, nine out of eleven studies that tested the association between 25 (OH) D and body mass index reported an inverse and significant relationship between 25 (OH) D and obesity. In conclusion, sufficient concentrations of vitamin D are related to a more favorable cardiometabolic profile, and children and adolescents who are obese or insufficiently active have a higher risk of present hypovitaminosis D

Esta revisão sistemática objetivou sintetizar evidências de estudos transversais sobre as associações entre atividade física, fatores de risco cardiometabólicos e concentrações de vitamina D em crianças e adolescentes. A busca foi realizada na PubMed, SciELO, LILACS, Scopus, MEDLINE e SPORTDiscus. No presente estudo, fatores de risco cardiometabólico incluíram obesidade, resistência à insulina, hipertensão arterial sis-têmica e alterações desfavoráveis no perfil lipídico (high density lipoprotein baixo, low density lipoprotein e triglicerídeos elevados). Estudos originais com delineamento transversal, publicados entre 2007 e 2019, avaliando a relação entre vitamina D e atividade física e/ou vitamina D e fatores de risco cardiometabólico foram incluídos. No total, quatorze estudos foram selecionados, envolvendo 8340 crianças e adolescentes. Os principais resultados encontrados foram relação inversa significativa entre os níveis de vitamina D e os fatores de risco cardiometabólico. Todos os estudos (n = 8) que testaram a associação entre atividade física e concentrações de 25-hidroxivitamina D (25 (OH) D) mostraram uma relação direta e significativa entre eles. Além disso, nove dos onze estudos que testaram a associação entre 25 (OH) D e índice de massa corporal apresentaram uma relação inversa e significativa entre 25 (OH) D com obesidade. Conclui-se que concen-trações suficientes de vitamina D estão relacionadas a um perfil cardiometabólico mais favorável. Crianças e adolescentes obesos ou insuficientemente ativos têm maior risco de apresentar hipovitaminose D