Resumo Apesar das mudanças observadas nos relacionamentos sociais nos últimos anos, especialmente entre as gerações mais novas, pouca evidência está disponível sobre os fatores associados à percepção dos relacionamentos sociais. Neste estudo nós investigamos a associação entre a percepção das próprias relações sociais, comportamentos associados à saúde, maturação biológica e indicadores de saúde mental em adolescentes. Este é um estudo transversal conduzido com 1.336 adolescentes (605 meninos e 731 meninas) com idades entre 10 e 17 anos, alunos de escolas públicas. A percepção dos relacionamentos sociais (família, amigo e professores), frequência de sentimentos de estresse e tristeza, o desempenho acadêmico, consumo de álcool, tabaco e alimentos gordurosos, bem como o nível de atividade física e tempo de tela foram avaliados por questionário. A maturação biológica foi estimada a partir do pico de velocidade de crescimento. Observamos que as piores relações sociais percebidas estiveram relacionadas ao consumo de tabaco (família e professores), de álcool (professores), alto consumo de alimentos gordurosos (professores), sentimentos de estresse (família e professores) e de tristeza (família e amigos) mais frequentes, e pior percepção do desempenho acadêmico (amigos e professores).

Abstract Although changes have been observed in social relationships in the recent years, especially among younger generations, little evidence is available concerning factors associated with adolescents’ perceived social relationships. In this study we investigated the association between self-perceived social relationships, health-related behaviors, biological maturation, and mental health in adolescents. This is a cross-sectional study conducted with 1,336 adolescents (605 boys and 731 girls) aged between 10 to 17 years from public schools. Self-perceived social relationships (family, friends, and teachers), feelings of stress and sadness, academic performance, tobacco smoking, alcohol and fat consumption, physical activity, and screen time were evaluated by a questionnaire. Biological maturation was assessed by the peak height velocity. We observed that worse perceived social relationships were associated with tobacco smoking (family and teachers), alcohol drinking (teachers), higher consumption of fat (teachers), greater feelings of stress (family and teachers) and sadness (family and friends), and poor academic achievement (friends and teachers).

Resumo Apesar das mudanças observadas nos relacionamentos sociais nos últimos anos, especialmente entre as gerações mais novas, pouca evidência está disponível sobre os fatores associados à percepção dos relacionamentos sociais. Neste estudo nós investigamos a associação entre a percepção das próprias relações sociais, comportamentos associados à saúde, maturação biológica e indicadores de saúde mental em adolescentes. Este é um estudo transversal conduzido com 1.336 adolescentes (605 meninos e 731 meninas) com idades entre 10 e 17 anos, alunos de escolas públicas. A percepção dos relacionamentos sociais (família, amigo e professores), frequência de sentimentos de estresse e tristeza, o desempenho acadêmico, consumo de álcool, tabaco e alimentos gordurosos, bem como o nível de atividade física e tempo de tela foram avaliados por questionário. A maturação biológica foi estimada a partir do pico de velocidade de crescimento. Observamos que as piores relações sociais percebidas estiveram relacionadas ao consumo de tabaco (família e professores), de álcool (professores), alto consumo de alimentos gordurosos (professores), sentimentos de estresse (família e professores) e de tristeza (família e amigos) mais frequentes, e pior percepção do desempenho acadêmico (amigos e professores).

Abstract Although changes have been observed in social relationships in the recent years, especially among younger generations, little evidence is available concerning factors associated with adolescents’ perceived social relationships. In this study we investigated the association between self-perceived social relationships, health-related behaviors, biological maturation, and mental health in adolescents. This is a cross-sectional study conducted with 1,336 adolescents (605 boys and 731 girls) aged between 10 to 17 years from public schools. Self-perceived social relationships (family, friends, and teachers), feelings of stress and sadness, academic performance, tobacco smoking, alcohol and fat consumption, physical activity, and screen time were evaluated by a questionnaire. Biological maturation was assessed by the peak height velocity. We observed that worse perceived social relationships were associated with tobacco smoking (family and teachers), alcohol drinking (teachers), higher consumption of fat (teachers), greater feelings of stress (family and teachers) and sadness (family and friends), and poor academic achievement (friends and teachers).

ABSTRACT BACKGROUND: Physical activity (PA) practices seem to differ between weekdays and weekends and these pattern changes can affect body fat differently. However, previous studies did not assess the mediation effect of weekday and weekend PA on maintenance of body fat using sophisticated statistical models. OBJECTIVE: To analyze the mediation effect of PA during weekdays and weekends on maintenance of fat mass over a 12-month follow-up. DESIGN AND SETTING: Longitudinal cohort study (12 months) conducted at a public university in Presidente Prudente, Brazil. METHODS: A sample of 225 adults (117 females) was used. Body fatness and fat mass were assessed using dual-energy X-ray absorptiometry. PA levels were assessed using a pedometer. The statistical analysis consisted of paired-sample t tests, independent-sample t tests, Pearson correlations and mediation models. RESULTS: After 12 months, weekend PA had decreased while body composition indicators remained stable (without changes). The correlation between fat mass at baseline and follow-up was high for both sexes (men: 0.966; women: 0.941; P-value = 0.001 for both). Moreover, PA indices were inversely but moderately related to fat mass at baseline and follow-up. Lastly, weekend PA mediated the association between fat mass at baseline and follow-up (P-value < 0.05) by around 2% and 4%. CONCLUSION: Weekend PA mediated the association between fat mass at baseline and fat mass after one year of follow-up among these adults. Further studies are required to investigate the association between physical activity, body fat and other variables such as dietary patterns and sleep time.

RESUMO Objetivo: Avaliar o tracking da aptidão cardiorrespiratória da infância à adolescência, bem como testar a via de moderação pela maturação somática. Métodos: A amostra foi composta de 375 crianças (197 meninos), com idades entre 7 e 10 anos na linha de base. Os sujeitos foram acompanhados por três anos. Massa corporal e estatura foram mensuradas como indicadores antropométricos e usadas para estimar a maturação somática pelo método de Moore. Aptidão cardiorrespiratória foi avaliada pelo teste de 9 minutos de corrida. Adiposidade corporal foi estimada pelo método de dobras subcutâneas, com medidas das dobras tricipital e subescapular, além de ter sido utilizada como covariável. A amostra foi categorizada em tercis, e então o coeficiente Kappa (k) e o coeficiente de correlação de concordância de Lin (LCCC) foram adotados para verificar estabilidade. Foram criadas variáveis dummy nas regressões para estimar o efeito de moderação. Todas as análises foram conduzidas no Stata 14.0, adotando p<0,05. Resultados: A aptidão cardiorrespiratória apresentou tracking baixo a moderado da infância para a adolescência (k=0,294; LCCC=0,458). Além disso, o status de maturação moderou significativamente a associação entre aptidão cardiorrespiratória na infância e adolescência (independentemente da coorte e adiposidade) em meninos (β=0,644; p<0,003) e na amostra total (β=0,184; p<0,020), mas não em meninas (-0,217; p=0,413). Conclusões: O tracking da aptidão cardiorrespiratória da infância à adolescência é baixo a moderado em ambos os sexos. Ainda, o estado maturacional moderou a associação entre aptidão cardiorrespiratória na infância e adolescência. Menor idade do pico de velocidade de crescimento foi associada à maior aptidão cardiorrespiratória.

ABSTRACT Objective: To evaluate cardiorespiratory fitness’ tracking from childhood to adolescence, as well as to test the moderation role of somatic maturation. Methods: Our sample was composed by 375 children (197 boys), with a baseline age between 7 and 10 years old. The children were followed-up over three years. Body mass and stature were measured as anthropometric indicators and were used to estimate maturity status through Moore’s method. Cardiorespiratory fitness was evaluated through 9-minute running test. Body adiposity was estimated through the subcutaneous skinfold method, with measures of triceps and subscapular skinfolds and used as a covariate. Sample was categorized into tertiles. Thereafter, the Kappa (k) coefficient and Lin’s concordance correlation coefficient (LCCC) tests were adopted to verify stability. Dummy variable in regression was used to test moderation effects. All analyses were conducted in Stata 14.0, adopting p<0.05. Results: Cardiorespiratory fitness presented a moderate to low tracking from childhood to adolescence (k=0.294; LCCC=0.458). Moreover, maturity status significantly moderated the association between cardiorespiratory fitness at childhood and adolescence (regardless of cohort and body adiposity) among boys (β=0.644; p=0.003) and role sample (β=0.184; p=0.020), but not girls (-0.217; p=0.413). Conclusions: Tracking of cardiorespiratory fitness from childhood to adolescence is moderate to low in both sexes. Moreover, maturity status moderated the relationship between cardiorespiratory fitness at baseline and in adolescence. A lower age at peak height velocity was associated to a greater cardiorespiratory fitness.

ABSTRACT BACKGROUND: Sports participation plays an important role in bone gain during childhood and adolescence. The aim here was to identify sex-related determinants of bone mineral density (BMD) differences between male and female adolescents, with emphasis on the role of sports participation. DESIGN AND SETTING: Longitudinal study conducted in a public university in Presidente Prudente, Brazil. METHODS: The sample comprised 48 adolescents aged 11-17 years, of both sexes, who were matched according to sex, age and sports participation. BMD was the main outcome, while muscle mass, sports participation, calendar age and biological maturation were treated as covariates. Participants were followed up after nine months. RESULTS: At baseline, BMD values were similar between the sexes. However, adjustment for covariates showed that BMD was higher among girls at all sites, with a contribution from lean soft tissue (LST) in the model (partial eta-squared, ES-r = 0.619 in upper limbs; 0.643 in lower limbs; 0.699 in spine; and 0.599 in whole body). Sports participation only explained the upper-limb variance (ES-r = 0.99). At the follow-up, the results resembled the baseline except in the lower limbs (P = 0.109), in which BMD was similar between the groups. BMD gain over time was similar between girls and boys in all segments, and baseline LST affected upper-limb and whole-body BMD accrual (ES-r = 0.396 and 0.107, respectively). CONCLUSION: Whole-body and specific-site BMD differed between baseline and follow-up. However,BMD accrual was similar between the sexes, given that muscle mass constituted the most relevant determinant of the difference between them.

ABSTRACT BACKGROUND: Our aim was to analyze multilevel correlates of cardiorespiratory fitness (CRF) according to sex, nutritional status and maturity status among adolescents. DESIGN AND SETTING: Cross-sectional study conducted in public schools. METHODS: This was a cross-sectional study on 1,209 adolescents aged between 10 and 17 years. CRF was estimated from the 20-meter shuttle run test. Anthropometric data on body mass index and waist circumference were obtained. Somatic maturation was assessed from the peak height velocity. Questionnaires were used to evaluate socioeconomic variables (family income, parents’ education level and number of siblings) and behavioral variables (physical activity, screen time and alcohol and tobacco consumption) among the parents and adolescents. RESULTS: Boys, adolescents with normal weight and on-time maturers presented greater CRF (P < 0.05). Concerning socioeconomic correlates, girls (tobacco smoking, alcohol consumption, physical activity and screen time), adolescents with normal weight (alcohol consumption, physical activity and screen time), and on-time maturers (alcohol consumption, physical activity during childhood and habitual physical activity) demonstrated higher numbers of behavioral correlates with CRF. Normal-weight adolescents presented a higher number of biological correlates (chronological age, age at peak height velocity and waist circumference). CONCLUSIONS: Different correlates were observed according to sex, nutritional status and somatic maturation status. However, habitual physical activity, waist circumference and chronological age seemed to be the strongest factors associated with cardiorespiratory fitness among adolescents.

ABSTRACT BACKGROUND: This study aimed to investigate the relationship between total and segmental bone mineral density (BDM) and physical activity (PA) in different domains (school, leisure and sports) among adolescents and children. DESIGN AND SETTING: Cross-sectional study in the Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP). METHODS: The study sample consisted of 173 children and adolescents (10.31 ± 1.87 years). The BMDs for the whole body (WB) and the regions of the trunk and legs were measured using dual energy X-ray absorptiometry (DXA). PA was measured using the Baecke questionnaire. A regression model was used to analyze the relationship between all the BMDs and the different domains of PA. RESULTS: 41.5% of the adolescents had high percentages of body fat. Regarding the comparison between physically active and insufficiently active adolescents, there were no statistically significant differences in any BMD variables (P > 0.05). The BMD of the legs showed positive relationships with the total PA (β = 0.009; P = 0.013) and sports PA (β = 0.010; P = 0.049) after insertion of the confounders. Similarly, the WB BMD showed the same relationships (total PA: β = 0.005; P = 0.045; and sports PA: β = 0.008; P = 0.049). No relationship was found between leisure and school PA and any of the BMDs (P > 0.05). CONCLUSION: The results indicated that practice of sport was related to higher BMD values, independent of sex, age and body fatness.

RESUMO CONTEXTO E OBJETIVO: O pico de velocidade de crescimento (PVC) constitui importante evento maturacional durante a adolescência, afetando o tamanho do esqueleto. O objetivo do estudo foi comparar variáveis ósseas em adolescentes praticantes de diferentes modalidades esportivas, bem como identificar se diferenças nas variáveis ósseas atribuídas à prática esportiva são dependentes do estado da maturação somática. DESENHO E LOCAL: Estudo transversal, Universidade Estadual Paulista (UNESP). MÉTODOS: O estudo foi constituído por 93 adolescentes (12 a 16,5 anos), divididos em três grupos: grupo sem envolvimento esportivo (n = 42), futebol/basquete (n = 26) e natação (n = 25). A densidade e conteúdo mineral ósseo foram mensurados utilizando absortiometria de raio-x de dupla energia e a maturação somática foi estimada através do uso do PVC. Informações sobre volume de treinamento foram fornecidas pelos treinadores. RESULTADOS: Adolescentes com idade tardia no PVC apresentaram maiores valores de densidade mineral óssea em membros superiores (P = 0,018). Após ajustes por variáveis de confusão, como a maturação somática, os nadadores apresentaram menores valores de densidade mineral óssea em membros inferiores, coluna e corpo inteiro. Apenas a densidade mineral óssea de membros superiores foi similar entre os grupos. Existiu relação negativa entre conteúdo mineral ósseo de corpo inteiro e tempo de treino semanal (β: -1563.967; 95% intervalo de confiança, IC: -2916.484 a -211.450). CONCLUSÃO: As diferenças em variáveis ósseas atribuídas à prática esportiva ocorrem independentemente da maturação, enquanto elevada quantidade de treinamento em situações de hipogravidade parece estar relacionada com menor massa óssea em nadadores.

ABSTRACT CONTEXT AND OBJECTIVE: Peak height velocity (PHV) is an important maturational event during adolescence that affects skeleton size. The objective here was to compare bone variables in adolescents who practiced different types of sports, and to identify whether differences in bone variables attributed to sports practice were dependent on somatic maturation status. DESIGN AND SETTING: Cross-sectional study, São Paulo State University (UNESP). METHODS: The study was composed of 93 adolescents (12 to 16.5 years old), divided into three groups: no-sport group (n = 42), soccer/basketball group (n = 26) and swimming group (n = 25). Bone mineral density and content were measured using dual-energy x-ray absorptiometry and somatic maturation was estimated through using peak height velocity. Data on training load were provided by the coaches. RESULTS: Adolescents whose PHV occurred at an older age presented higher bone mineral density in their upper limbs (P = 0.018). After adjustments for confounders, such as somatic maturation, the swimmers presented lower values for bone mineral density in their lower limbs, spine and whole body. Only the bone mineral density in the upper limbs was similar between the groups. There was a negative relationship between whole-body bone mineral content and the weekly training hours (β: -1563.967; 95% confidence interval, CI: -2916.484 to -211.450). CONCLUSION: The differences in bone variables attributed to sport practice occurred independently of maturation, while high training load in situations of hypogravity seemed to be related to lower bone mass in swimmers.

Abstract AIM To compare bone mass and body composition variables between adolescents engaged in high-impact sports and adults who were sedentary during early life. METHOD A cross-sectional study with 155 participants (64 adolescents and 91 adults) aged between 11 and 50 years old. Among the adults, history of sports was evaluated during face-to-face interviews, and information regarding the adolescents' training routines was provided by their coaches. Body composition was evaluated using Dual Energy X-Ray Absorptiometry which provided data about bone mineral density (BMD), bone mineral content (BMC), fat mass (FM), and free fat mass (FFM). RESULTS Adults who engaged in sports practice during early life had higher values of BMC (ES-r = 0.063), FFM (ES-r = 0.391), and lower values of FM (ES-r = 0.396) than sedentary adults. Higher values of BMC (ES-r = 0.063) and BMD in lower limbs (ES-r = 0.091) were observed in active adolescents. Adolescents engaged in sports and adults who were sedentary in early life presented similar values in all bone variables, FM, and FFM. CONCLUSIONS Sports involvement in early life is related to higher bone mass in adulthood. Adolescents engaged in sports presented similar bone mass to adults who had been sedentary in early life.

Resumo Objetivo: Analisar a relação entre a prática de artes marciais (judô, karatê e kung-fu) e a densidade mineral óssea em adolescentes. Métodos: O estudo foi composto por 138 adolescentes (48 praticantes de artes marciais e 90 não praticantes) de ambos os sexos, com média de 12,6 anos. A densidade mineral óssea foi medida com absortometria radiológica de dupla energia em braços, pernas, coluna, tronco, pelve e total. A carga de treinamento semanal e o tempo anterior de envolvimento na modalidade esportiva foram relatados pelo treinador. A correlação parcial testou a associação entre a carga semanal de treinamento e a densidade mineral óssea, controlada para sexo, idade cronológica, prática anterior e maturação somática. A análise de covariância foi usada para comparar os valores de densidade mineral óssea de acordo com os grupos controle e de artes marciais, controlados para sexo, idade cronológica, prática anterior e maturação somática. Associações significativas entre a densidade mineral óssea e a massa muscular foram inseridas em um modelo multivariado e as inclinações dos modelos foram comparadas com o teste t de Student (controle versus arte marcial). Resultados: Os adolescentes envolvidos na prática de judô apresentaram valores maiores de densidade mineral óssea do que os do grupo controle (p=0,042; tamanho de efeito médio [eta-quadrado=0,063]), enquanto a relação entre a quantidade de treinos semanais e a densidade mineral óssea foi significativa entre os adolescentes praticantes de judô (braços [r=0,308] e pernas [r=0,223]) e kung-fu (braços [r=0,248] e coluna [r=0,228]). Conclusões: Diferentes modalidades de artes marciais estão relacionadas com maior densidade mineral óssea em diferentes regiões do corpo em adolescentes.

Abstract Objective: The purpose of this study was to analyze the relationship between martial arts practice (judo, karate and kung-fu) and bone mineral density in adolescents. Methods: The study was composed of 138 (48 martial arts practitioners and 90 non-practitioners) adolescents of both sexes, with an average age of 12.6 years. Bone mineral density was measured using Dual-Energy X-ray Absorptiometry in arms, legs, spine, trunk, pelvis and total. Weekly training load and previous time of engagement in the sport modality were reported by the coach. Partial correlation tested the association between weekly training load and bone mineral density, controlled by sex, chronological age, previous practice and somatic maturation. Analysis of covariance was used to compare bone mineral density values according to control and martial arts groups, controlled by sex, chronological age, previous practice and somatic maturation. Significant relationships between bone mineral density and muscle mass were inserted into a multivariate model and the slopes of the models were compared using the Student t test (control versus martial art). Results: Adolescents engaged in judo practice presented higher values of bone mineral density than the control individuals (p-value=0.042; Medium Effect size [Eta-squared=0.063]), while the relationship between quantity of weekly training and bone mineral density was significant among adolescents engaged in judo (arms [r=0.308] and legs [r=0.223]) and kung-fu (arms [r=0.248] and spine [r=0.228]). Conclusions: Different modalities of martial arts are related to higher bone mineral density in different body regions among adolescents.

OBJETIVO: Analisar a associação entre sarcopenia, fatores sociodemográficos e doenças crônicas não transmissíveis em idosos longevos. MÉTODOS: A amostra foi constituída por 120 idosos - 76 mulheres (83,4±3,0 anos) e 44 homens (83,4±2,6 anos) -, com idade entre 80 e 95 anos (83,4±2,9 anos), residentes na cidade de Presidente Prudente (SP), Brasil. Os fatores sociodemográficos e epidemiológicos investigados foram: estrato etário, sexo, estado civil, escolaridade, doenças crônicas não transmissíveis, etnia e estado nutricional. A análise da composição corporal foi feita pela técnica de absorptiometria de raios-X de dupla energia, e, para identificação da sarcopenia, foi utilizada a razão da massa apendicular (massa magra dos membros superiores mais massa magra dos membros inferiores [kg]/estatura [m]2). Para tratamento estatístico, foi empregado o teste Qui-quadrado para analisar a associação entre os fatores sociodemográficos, epidemiológicos e sarcopenia, e a análise de regressão logística binária foi utilizada para expressar a magnitude das associações. Foi utilizado o software Statistical Package for the Social Sciences (17.0), e o nível de significância estabelecido foi de 5%. RESULTADOS: Os fatores que se associaram com a sarcopenia foram: sexo, idade, estado nutricional, osteopenia/osteoporose. CONCLUSÃO: O sexo, a idade, o estado nutricional e a presença de osteopenia/osteoporose são fatores que estão independentemente associados à sarcopenia em idosos longevos.

OBJECTIVE: To analyze whether sarcopenia is associated with sociodemographic factors and chronic noncommunicable diseases in adults aged 80 years and older. METHODS: The sample consisted of 120 adults aged 80 to 95 years (83.4±2.9 years) from the city of Presidente Prudente (São Paulo, Brazil), of which 76 were females (83.4±3.0 years) and 44 were males (83.4±2.6 years). The study sociodemographic and epidemiological factors were: age stratum, gender, marital status, education level, chronic noncommunicable diseases, ethnicity, and nutritional status. Body composition was determined by Dual-Energy X-Ray Absorptiometry and sarcopenia was identified by the appendicular lean mass ratio (upper limb lean mass + lower limb lean mass [kg]/height [m]2). The Chi-square test analyzed whether sarcopenia was associated with sociodemographic and epidemiological factors and binary logistic regression expressed the magnitude of the associations. The data were treated by the software Statistical Package for the Social Sciences (17.0) at a significance level of 5%. RESULTS: The factors associated with sarcopenia were gender, age, nutritional status, and osteopenia/osteoporosis. CONCLUSION: The factors gender, age, nutritional status, and osteopenia/osteoporosis are independently associated with sarcopenia in adults aged 80 years and older.