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.

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.

Adrb2 gln27glu polymorphism associated with adiposity indicators and il-10 in adolescents / Polimorfismo adrb2 gln27glu associado a indicadores de adiposidade e il-10 em adolescentes / Polimorfismo adrb2 gln27glu asociado a indicadores de adiposidad e il-10 en adolescentes

ABSTRACT Introduction: Studies of association between obesity and genetic factors have demonstrated a significant contribution of polymorphisms related to body fat distribution and subclinical inflammatory process. Objective: To investigate the association between genotypes of the Gln27Glu polymorphism of the ADRB2 gene and indicators of adiposity, inflammatory markers, metabolic parameters and parameters of physical fitness in overweight adolescents. Methods: A total of 44 male and female adolescents, aged between 13 and 17 years, with positive clinical diagnosis of overweight, were divided into two groups according to the Gln27Glu polymorphism genotypes of the ADRB2 gene: a) Group of carriers of the 27Glu allele (Gln27Glu/Glu27Glu) (n = 22); b) Group of non-carriers of the 27Glu allele (Gln27Gln) (n = 22). Both groups were evaluated for body composition, sexual maturation, cardiorespiratory fitness variables and indicators of muscle strength. Basal glycemia and insulin, lipid profile and inflammatory profile were measured. Abdominal subcutaneous and visceral adiposities were evaluated by ultrasonography. Genotyping of the Gln27Glu polymorphism of the ADRB2 gene was performed by the Taqman allelic discrimination assay. Results: The genotype frequency found was: Gln/Gln (n = 22) (50.0%), Gln/Glu (n = 18) (41.0%) and Glu/Glu (n = 4) %). The frequency of the 27Glu allele was 29.5%. The group of adolescent carriers of the 27Glu allele of the ADRB2 gene presented higher mean adiposity indicators (abdominal circumference, trunk fat mass and visceral fat), as well as lower IL-10 concentrations when compared to non-carriers. Conclusions: The 27Glu allele was associated with adiposity indicators in overweight adolescents, while subcutaneous abdominal fat exhibited an inverse relationship with inflammatory variables and maximum oxygen uptake, which may result in more damage to health. Level of evidence III; Case-control study.

RESUMO Introdução: Estudos de associação entre a obesidade e fatores genéticos têm demonstrado a significativa contribuição de polimorfismos relacionados à distribuição de gordura corporal e processo inflamatório subclínico. Objetivo: Investigar a associação entre os genótipos do polimorfismo Gln27Glu do gene ADRB2 e indicadores de adiposidade, marcadores inflamatórios, parâmetros metabólicos e de aptidão física em adolescentes com excesso de peso. Métodos: Participaram 44 adolescentes, de ambos os sexos, com idade entre 13 e 17 anos, com diagnóstico clínico positivo de excesso de peso, divididos em dois grupos conforme os genótipos do polimorfismo Gln27Glu do gene ADRB2: a) Grupo de portadores do alelo 27Glu (Gln27Glu/Glu27Glu) (n=22); b) Grupo de não portadores do alelo 27Glu (Gln27Gln) (n=22). Ambos os grupos foram avaliados quanto à composição corporal, maturação sexual, variáveis de aptidão cardiorrespiratória e indicadores de força muscular. Foram dosados glicemia e insulina basais, perfil lipídico e perfil inflamatório. As adiposidades abdominais subcutânea e visceral foram avaliadas através de ultrassonografia. A genotipagem do polimorfismo Gln27Glu do gene ADRB2 foi realizada através do ensaio de discriminação alélica Taqman. Resultados: A frequência genotípica encontrada foi: Gln/Gln (n=22) (50,0%), Gln/Glu (n=18) (41,0%) e Glu/Glu (n=4) (9,0%). A frequência do alelo do 27Glu foi de 29,5%. O grupo de adolescentes portadores do alelo 27Glu do gene ADRB2 apresentou maiores médias de indicadores de adiposidade (circunferência abdominal, massa gorda troncular e gordura visceral), assim como menores concentrações de IL-10 quando comparados aos não portadores. Conclusões: O alelo 27Glu apresentou associação com os indicadores de adiposidade em adolescentes com excesso de peso, assim como a gordura abdominal subcutânea demonstrou relação inversa com as variáveis inflamatórias e o consumo máximo de oxigênio, podendo resultar em maiores prejuízos à saúde. Nível de evidência III; Estudo de caso-controle.

RESUMEN Introducción: Estudios de asociación entre la obesidad y factores genéticos han demostrado la significativa contribución de polimorfismos relacionados a la distribución de grasa corporal y proceso inflamatorio subclínico. Objetivo: Investigar la asociación entre los genotipos del polimorfismo Gln27Glu del gen ADRB2 e indicadores de adiposidad, marcadores inflamatorios, parámetros metabólicos y de aptitud física en adolescentes con exceso de peso. Métodos: Participaron 44 adolescentes, de ambos sexos, con edad entre 13 y 17 años, con diagnóstico clínico positivo de exceso de peso, divididos en dos grupos según los genotipos del polimorfismo Gln27Glu del gen ADRB2: a) Grupo de portadores del alelo 27Glu (Gln27Glu/Glu27Glu) (n = 22); b) Grupo de no portadores del alelo 27Glu (Gln27Gln) (n = 22). Ambos grupos fueron evaluados cuanto a la composición corporal, madurez sexual, variables de aptitud cardiorrespiratoria e indicadores de fuerza muscular. Fueron dosificadas glucemia e insulina basales, perfil lipídico y perfil inflamatorio. Las adiposidades abdominales subcutánea y visceral fueron evaluadas a través de ultrasonografía. El genotipado del polimorfismo Gln27Glu del gen ADRB2 fue realizado a través del ensayo de discriminación alélica Taqman. Resultados: La frecuencia genotípica encontrada fue: Gln/Gln (n = 22) (50,0%), Gln/Glu (n = 18) (41,0%) y Glu/Glu (n = 4) (9,0%). La frecuencia del alelo del 27Glu fue del 29,5%. El grupo de adolescentes portadores del alelo 27Glu del gen ADRB2 presentó mayores promedios de indicadores de adiposidad (circunferencia abdominal, masa grasa troncular y grasa visceral), así como menores concentraciones de IL-10, en comparación con los no portadores. Conclusiones: El alelo 27Glu presentó asociación con los indicadores de adiposidad en adolescentes con exceso de peso, así como la grasa abdominal subcutánea demostró relación inversa con las variables inflamatorias y el consumo máximo de oxígeno, lo que puede resultar en mayores perjuicios a la salud. Nivel de Evidencia III; Estudio de caso-control.

Localized fat-free mass does not influence muscle strength in obese and non-obese boys / Massa livre de gordura localizada não influencia força muscular em rapazes obesos e não obesos / Masa libre de grasa localizada no influencia la fuerza muscular en jóvenes obesosy no obesos

INTRODUCTION: Obesity in adolescents has increased worldwide, and is generally associated with poor eating habits and physical inactivity. OBJECTIVE: To compare absolute and relative muscle strength with body mass (BM), fat-free mass (FFM) and localized FFM of upper and lower limbs among obese and non-obese adolescents. METHODS: BM, height and body mass index (BMI) were verified in 39 male adolescents (aged 13-17 years). Body composition was measured by dual-energy X-ray absorptiometry (DXA) and maximal strength of upper and lower limbs was estimated by a one-repetition maximum (1RM) test. Participants were divided into three groups: eutrophic (normal weight) (n=11), overweight (n=14), and obese (n=14). One-way ANOVA was used to compare the variables, followed by a Bonferroni post-hoc test for multiple comparisons. Pearson's correlation coefficient was used for relevant correlations and multiple linear regression to verify the influence of anthropometric variables, body composition and muscle strength of upper and lower limbs. RESULTS: Obese and overweight adolescents had absolute muscle strength values similar to those of the eutrophic adolescents, which were lower when corrected by BM (p<0.001). However, muscle strength related to FFM and localized FFM were similar between groups in both upper and lower limbs. Linear regression showed that BMI explained 59% of the variation in absolute muscle strength of the lower limbs (ß=0.59, p<0.05), FFM explained 84% of the variation in absolute muscle strength of the upper limbs (ß=0.84, p<0.01) and 68% of the lower limbs (ß=0.68; p<0.01), while localized FM was inversely associated in the lower limbs (ß=−0.53, p<0.05). CONCLUSION: Muscle strength of lower and upper limbs, when corrected by localized FFM, does not distinguish between overweight and normal weight adolescents, indicating that obesity does not have a negative effect on generation of muscle strength in obese boys. Level of Evidence III; Case-control study.

INTRODUÇÃO: A obesidade em adolescentes tem aumentado em todo o mundo, geralmente associada a hábitos alimentares inadequados e inatividade física. OBJETIVO: Comparar a força muscular absoluta e relativa com a massa corporal (MC), massa livre de gordura (MLG) e MLG localizada dos membros superiores e inferiores entre adolescentes obesos e não obesos. MÉTODOS: Em 39 adolescentes do sexo masculino (entre 13 e 17 anos) foram verificados MC, estatura e índice de massa corporal (IMC). A composição corporal foi medida por absorciometria de raios-x de dupla energia (DXA) e a força máxima de membros superiores e inferiores foi estimada por um teste de repetição máxima (1RM). Os participantes foram divididos em três grupos: eutrófico (n = 11), sobrepeso (n = 14) e obeso (n = 14). Utilizou-se o teste One-way ANOVA para comparar as variáveis, seguido de teste post hoc de Bonferroni para comparações múltiplas, para as correlações relevantes, usou-se o coeficiente de correlação de Pearson e a regressão linear múltipla foi usada para verificar a influência das variáveis antropométricas, composição corporal e a força muscular dos membros superiores e inferiores. RESULTADOS: Os adolescentes obesos e com sobrepeso tinham força muscular absoluta similar aos dos eutróficos, sendo menores quando corrigidas pela MC (p < 0,001). Porém, a força muscular relacionada com a MLG e a MLG localizada foi semelhante entre os grupos, tanto em membros superiores como inferiores. A regressão linear mostrou que o IMC explicou 59% da variação da força muscular absoluta dos membros inferiores (ß = 0,59, p < 0,05), a MLG explicou 84% da variação da força muscular absoluta dos membros superiores (ß = 0,84, p < 0,01) e 68% dos membros inferiores (ß = 0,68; p < 0,01), enquanto a massa gorda localizada foi inversamente associada nos membros inferiores (ß = −0,53; p < 0,05). CONCLUSÃO: A força muscular dos membros superiores e inferiores, quando corrigida pela MLG localizada, não diferencia adolescentes com sobrepeso e eutróficos, indicando que a obesidade não afeta negativamente a geração de força muscular em rapazes obesos. Nível de Evidência III; Estudo de caso-controle.

INTRODUCCIÓN: La obesidad en adolescentes ha aumentado en todo el mundo, generalmente asociada a malos hábitos alimenticios y falta de actividad física. OBJETIVO: Comparar fuerza muscular absoluta y relativa de la masa corporal (MC), MLG y MLG localizada en miembros inferiores y superiores entre adolescentes obesos y no obesos. MÉTODOS: Se verificó en 39 adolescentes hombres (entre 13 y 17 años) sus MC, estaturas e índices de masa corporal (IMC). La composición corporal fue mensurada por absorciometría de rayos-x de doble energía (DXA) y el test de repetición máxima para estimar la fuerza máxima de miembros superiores e inferiores, divididos en tres grupos: 11 eutróficos, 14 con sobrepeso y 14 obesos. Se usó ANOVA (one way) para comparación de variables, seguido de Post Hoc de Bonferroni para comparaciones múltiples, correlaciones por el coeficiente de correlación Pearson y Regresión Lineal Múltiple para la influencia de variables antropométricas, composición corporal y fuerza muscular de miembros inferiores y superiores. RESULTADOS: Obesos y con sobrepeso presentaron valores de fuerza muscular absoluta similares a los eutróficos, pero menor si se corrigen por MC (p<0,001). Sin embargo, la fuerza muscular relativa a MLG y MLG localizada fue semejante. En regresión lineal, el IMC explicó el 59% de variación de fuerza muscular absoluta en miembros inferiores (ß=0,59, p<0,05), MLG 84% de variación de fuerza muscular absoluta en miembros superiores (ß=0,84, p<0,01) y 68% en miembros inferiores (ß=0,68; p<0,01), mientras que la MG localizada fue inversamente asociada a los superiores (ß=−0,53; p<0,05). CONCLUSIÓN: La fuerza muscular de miembros superiores e inferiores, cuando es corregida por la MLG localizada, no se diferencia en adolescentes con sobrepeso y eutróficos, indicando que la obesidad no afecta negativamente la generación de fuerza muscular en jóvenes obesos. Nivel de Evidencia III; Estudio caso-control.