Sports participation plays a relevant role in the relationship between birth weight and bone mineral content in adolescents.

The Developmental Origins of Health and Disease hypothesis (DOHaD) proposes that growth during the prenatal period might play a critical role in health, affecting the development of diseases, such as osteoporosis. Bone health is particularly affected by human behaviors when sports participation constitutes the main manifestation of physical exercise. The aim of this study is to analyze the relationship between birth weight (BW) and bone mineral content (BMC) among adolescents, as well as to identify if sports participation and maturity can affect this relationship. The sample was composed of adolescents with ages ranging from 11 to 18 years, stratified according to normal birth weight (n = 331), low birth weight (n = 36), and macrosomia (n = 47), extracted from a wider cross-sectional study (ABCD Growth Study). BW was self-reported by the adolescent's parent. Sports participation was assessed by face-to-face interview. BMC was assessed using dual-energy X-ray absorptiometry. In the multivariate models, the relationships between BW and BMC remained non-significant, while sports participation was significantly related to BMC on lower limbs among boys (r = 0.154; p value = .001) and BMC of upper limbs among girls (r = 0.124; p value = .044). APHV was related to BMC of upper limbs among boys (r = 0.137; p value = .001). In conclusion, BMC was not affected by BW, while this phenomenon seems to be significantly affected by the positive impact of sports participation and maturation on it.

Mediation effects of lean mass and fat mass on the relationship between body mass index and handgrip strength.

OBJECTIVE: This study aimed to assess the mediation effects of lean mass and fat mass on the relationship between body mass index (BMI) and handgrip strength (HGS) in adolescents. METHOD: The sample included 118 adolescents (60 girls) aged 10-14 years. Body composition, determined from lean mass (LM) and fat mass (FM), was measured by dual-energy x-ray absorptiometry. HGS was measured using a digital dynamometer. Moderate-to-vigorous physical activity and sexual maturation, treated as covariates, were evaluated by accelerometry and pubic hair development, respectively. Spearman correlation and simple mediation analysis were used for statistical analysis. RESULTS: A positive relationship was observed between BMI and HGS (rho = .364, p < .001), BMI and LM (rho = .466, p < .001), LM and HGS (rho = .784, p < .001), BMI and FM (rho = .907, p < .001), and FM and HGS (rho = .291, p = .001). LM was the only significant mediator of the relationship between BMI and HGS. CONCLUSION: Only LM mediated the association between BMI and HGS, almost entirely explaining the relationship. The findings reinforce the need to include LM measurements in routine strength testing. Furthermore, strategies focused on LM development may be promising in preventing low muscle strength in adolescents.

Effects of Teasing in Physical Education Classes, Self-efficacy, and Physical Activity on Adolescents’ Self-esteem / [El efecto del hostigamiento en las clases de educación física, la autoeficacia y la actividad física en la autoestima de los adolescentes]

Objective: To investigate the differences between boys and girls in the present variables, and assess the possible associations between self-esteem and teasing in school physical education classes, self-efficacy, and physical activity among adolescents. Method: The sample included 944 adolescents aged 14 to 19 years (mean =16.52, SD = 1.12, 53.6% male), enrolled in public high schools in Florianópolis, Santa Catarina, Brazil. Information was collected on age, body mass index, physical activity level, self-efficacy, teasing experiences in physical education classes, and self-esteem (dependent variable). Self-esteem was assessed using the Rosenberg Self-esteem Scale. Results: Adolescents had a mean self-esteem score of 28.71 (out of 40), with boys having higher scores than girls (29.66 vs. 27.61, p < .001). In both sexes, adolescents who reported lower levels of teasing in physical education classes had higher self-esteem. Boys with high self-efficacy and higher levels of physical activity had higher self-esteem scores. Conclusion: Experiencing teasing in school physical education classes was a predictor of self-esteem in adolescents of both sexes, and self-efficacy and physical activity were predictors of self-esteem in boys.(AU)

Objetivo: Investigar las diferencias entre chicos y chicas en las variables de estudio, así como averiguar la posible asociación entre autoestima y el hostigamiento en las clases de educación física, autoeficacia y actividad física en adolescentes. Método: Se contó con una muestra de 944 de entre 14 y 19 años (media = 16.52, DT = 1.12, el 53.6% hombres) que estudiaban en centros escolares de Florianópolis, Santa Catarina, Brasil. Se recogió información sobre edad, índice de masa corporal, nivel de actividad física, autoeficacia, hostigamiento en las clases de educación física y autoestima (variable dependiente). La autoestima se midió mediante la Escala de Autoestima de Rosenberg. Resultados: La autoestima media de los adolescentes era 28.71 (de un máximo de 40), siendo más elevada la de los chicos que la de las chicas (29.66 vs. 27.61, p < .001). En ambos sexos la autoestima de los adolescentes que declaraban menos hostigamiento en educación física era superior. Los chicos que tenían una mayor autoeficacia y mayor actividad física tenían puntuaciones más elevadas en autoestima. Conclusión: Experimentar hostigamiento en las clases de educación física predecía la autoestima de los adolescentes de ambos sexos; la autoeficacia y la actividad física predecían la autoestima en los chicos.(AU)

Isolated and combined association of excessive screen time and physical inactivity with negative self-rated health in adolescents.

OBJECTIVE: The aim of this study was to analyze isolated and combined associations of physical inactivity excessive screen time with negative self-rated health, according to sex, among school adolescents. METHODS: In this cross-sectional study conducted with 2,517 adolescents in Amazonas State, participants were asked about their self-rated health with the following question: How do you rate your health? Responses were dichotomized into positive (excellent and good) and negative (regular, bad, and terrible). Information on sex, age group, family income, physical activity, and screen time (watching TV, using a computer, or playing video games) was collected through a self-administered questionnaire. Adolescents simultaneously classified as physically inactive (<60 min/day) and having excessive screen time (>2 h/day) were considered to have two risk factors. Data was analyzed using binary logistic regression. RESULTS: Out of every 10 adolescents, 2 had a negative self-rated health. After adjusting for age and family income, there were no isolated or combined associations between physical inactivity or excessive screen time and negative self-rated health in girls. In boys, negative self-rated health was associated with insufficient levels of physical activity (odds ratio [OR]: 2.39; 95% confidence interval [CI]: 1.03-5.59) and with the accumulation of two risk factors (OR: 1.61; 95%CI 1.10-2.34). CONCLUSIONS: Being insufficiently active and the combination of physical inactivity and excessive screen time become exposure factors to the negative self-rated health of adolescent boys.

Secular trends in physical activity in adolescents: A systematic review.

Objective: One in five adolescents has been estimated to perform sufficient physical activity (PA), thus potentially indicating that PA among adolescents has declined. This systematic review was aimed at reporting and summarizing the available knowledge regarding PA secular trends in adolescents over time. Methods: Seven databases were consulted (Web of Science, Scopus/Elsevier, Medline/PubMed, ScienceDirect, Lilacs, Physical Education Index, and SPORTDiscus), and 1809 studies were examined. According to the PRISMA guidelines, relevant research on secular PA trends in adolescents was screened for inclusion in a narrative synthesis. The risk of bias in the articles included was also assessed. Results: Forty-three studies with data collected between 1969 and 2018 met the inclusion criteria, and data from high-income countries predominated. PA was estimated predominantly by self-reporting, except in seven studies, and diverse contexts and domains were analyzed. Increased PA was reported in 16 studies (from 2.9% to 43.5%), decreased PA was reported in 15 studies (-2.5% to -69.5%), and no change was reported in 22 studies (-12.0% to 14.4%). Conclusions: Although PA has increased in some countries, very little information is available in low- and middle-income countries. Efforts should support studies on PA trends in adolescents from economically disadvantaged countries.

Secular trends in body image dissatisfaction and associated factors among adolescents (2007-2017/2018).

OBJECTIVE: To assess secular trends in body image dissatisfaction and associated factors among adolescents over a 10-year period (2007-2017/2018). METHODS: The sample included 1,479 (2007, n = 531; 2017/2018, n = 948) high school adolescents of both sexes, aged 14 to 18 years, of schools in a city in southern Brazil, in 2007 and 2017/2018. Data were collected on sex, age, physical activity (IPAQ, short form), anthropometric measurements (body weight, height, and triceps and subscapular skinfolds), and body image dissatisfaction (figure rating scale). The variables were compared with Independent samples t-test and Mann-Whitney U-test. The associations between sex and other variables were examined with chi-square test, and the factors associated with body image were identified with multinomial logistic regression. RESULTS: Most adolescents were dissatisfied with their body image in 2007 (65,2%) and 2017/2018 (71,1%). The prevalence of body dissatisfaction increased by 9.2% over the 10-year period, particularly dissatisfaction with thinness (21.3%). After stratification by sex, in 2017/2018 sample, dissatisfaction with overweight was 46.1% greater in boys, and dissatisfaction with thinness was 66.9% greater in girls. Factors found to be significantly associated with body image dissatisfaction were physical activity level, and body adiposity. CONCLUSIONS: There was a secular trend toward increased body image dissatisfaction in both sexes. Future efforts should go beyond scientific production, in public and private environments aimed at increasing awareness of health issues related to body care in the physical, psychological, and environmental domains.

Agreement Between Body Mass Index and Body Fat in Adolescents With Different Physical Activity Levels.

Purpose: This study aimed to verify the agreement between body mass index (BMI) and body fat in adolescents with different physical activity (PA) levels. Method: This cross-sectional study collected body fat data in 118 adolescents (aged 10 to 14 years) estimated using air-displacement plethysmography (ADP). Body mass 10 and height were used to calculate BMI. Physical activity levels were measured objectively by accelerometers. Results: For boys with low PA, BMI overestimated body fat values measured by ADP (mean error = -0.42; p = .018) which also occurred in group high PA (mean error = -0.76; p = .001). For girls, BMI underestimated body fat values measured by ADP values in group high PA (mean error = 0.43; p = .001) and low PA (mean error = 0.72; p < .001). Conclusion: It is recommended that researchers and practitioners 15 cautiously interpret BMI results, especially considering that most adolescents do not practice enough PA.

Isolated and combined association of excessive screen time and physical inactivity with negative self-rated health in adolescents / Associação isolada e combinada do tempo de tela excessivo e da inatividade física com autopercepção de saúde negativa em adolescentes

Abstract Objective: The aim of this study was to analyze isolated and combined associations of physical inactivity excessive screen time with negative self-rated health, according to sex, among school adolescents. Methods: In this cross-sectional study conducted with 2,517 adolescents in Amazonas State, participants were asked about their self-rated health with the following question: How do you rate your health? Responses were dichotomized into positive (excellent and good) and negative (regular, bad, and terrible). Information on sex, age group, family income, physical activity, and screen time (watching TV, using a computer, or playing video games) was collected through a self-administered questionnaire. Adolescents simultaneously classified as physically inactive (<60 min/day) and having excessive screen time (>2 h/day) were considered to have two risk factors. Data was analyzed using binary logistic regression. Results: Out of every 10 adolescents, 2 had a negative self-rated health. After adjusting for age and family income, there were no isolated or combined associations between physical inactivity or excessive screen time and negative self-rated health in girls. In boys, negative self-rated health was associated with insufficient levels of physical activity (odds ratio [OR]: 2.39; 95% confidence interval [CI]: 1.03-5.59) and with the accumulation of two risk factors (OR: 1.61; 95%CI 1.10-2.34). Conclusions: Being insufficiently active and the combination of physical inactivity and excessive screen time become exposure factors to the negative self-rated health of adolescent boys.

RESUMO Objetivo: Analisar a associação isolada e combinada do tempo excessivo de tela e inatividade física com a autopercepção negativa de saúde, de acordo com o sexo, em adolescentes estudantes. Métodos: Estudo transversal conduzido em 2.517 adolescentes amazonenses, os quais foram questionados sobre a autopercepção de saúde: "Como você considera a sua saúde?", dicotomizada em positiva (excelente, boa) e negativa (regular, ruim, péssima). Informações sobre sexo, faixa etária, renda familiar, atividade física e tempo excessivo de tela (assistindo TV, usando o computador ou jogando videogame) foram coletadas mediante questionário autoadministrado. Aqueles classificados, simultaneamente, como fisicamente inativos (<60 min/dia) e com tempo excessivo de tela (>2 horas/dia) foram considerados com dois fatores de risco. Os dados foram analisados utilizando-se a regressão logística binária. Resultados: Dois em cada dez adolescentes apresentaram autopercepção negativa de saúde. Após o ajuste pelas variáveis idade e renda familiar, não foram observadas, no sexo feminino, associações da inatividade física e do tempo excessivo de tela, de maneira isolada ou agrupada, com a autopercepção negativa de saúde. No sexo masculino, a percepção negativa de saúde foi associada com os níveis insuficientes de atividade física (odds ratio — OR: 2,39; intervalo de confiança — IC95% 1,03-5,59) e com o acúmulo de dois fatores de risco (OR: 1,61; IC95% 1,10-2,34). Conclusões: Ser insuficientemente ativo e associar a inatividade física com tempo excessivo de tela tornam-se fatores de exposição à percepção negativa em saúde de meninos adolescentes.

Agreement and validity between body fat estimated by skinfold measurement and air displacement plethysmography in adolescents / Concordância e validade entre a gordura corporal estimada por medidas de dobras cutâneas e pletismografia por deslocamento de ar em adolescentes

ABSTRACT Objective: Assess the agreement and validity between relative body fat percentages estimated using anthropometric measurements and air displacement plethysmography (ADP). Methods: A cross-sectional study was conducted on 118 adolescents (60 females) aged 10 to 14 years (x̄=12.19, sd=1.18). Adolescents were classified as eutrophic or with overweight according to body mass index (body weight/height2) (x̄=20,12, sd=3,56). Measurements of skinfold thickness (triceps and medial calf) were collected and used to estimate relative body fat by the Slaughter equation. ADP was used as a reference method for the estimation of relative body fat. Agreement between body fat measurement methods (anthropometry × ADP) was analyzed by the Bland-Altman method. The mean error (ME) was calculated by subtracting the body fat percentage estimated by the Slaughter equation from the body fat percentage estimated by ADP. Validity was tested with the concordance correlation coefficient (CCC). Results: There was no agreement between the methods, regardless of sex and weight status. For boys with overweight (ME = 4.52; p = 0.007), eutrophic girls (ME = 6.37; p < 0.001), and girls with overweight (ME = 5.55; p < 0.001), the Slaughter equation resulted in overestimation of body fat compared with ADP. Skinfold equations did not demonstrate validity when compared with ADP. Conclusion: Slaughter's skinfold equations did not demonstrate agreement and validity compared with ADP in either sex or weight status. Skinfold equations should be used with caution and, whenever possible, in combination with other body composition indicators.

RESUMO Objetivo: Avaliar a concordância e validade entre os percentuais de gordura corporal estimados usando medidas antropométricas e pletismografia por deslocamento de ar (PDA). Métodos: Um estudo transversal foi conduzido em 118 adolescentes (60 meninas) com idade entre 10 e 14 anos (x̄=12,19, dp=1,18). Os adolescentes foram classificados como eutróficos ou com sobrepeso de acordo com o índice de massa corporal (peso/altura2) (x̄=20,12, dp=3,56). Medidas de dobras cutâneas (tríceps e panturrilha medial) foram coletadas e utilizadas para estimar a gordura corporal relativa pela equação de Slaughter. A PDA foi utilizada como método de referência para a estimativa da gordura corporal relativa. A concordância entre os métodos de medida de gordura corporal (antropometria × PDA) foi analisada pelo método de Bland-Altman. O erro médio (EM) foi calculado subtraindo o percentual de gordura corporal estimado pela equação de Slaughter do percentual de gordura corporal estimado pela PDA. A validade foi testada com o coeficiente de correlação de concordância (CCC). Resultados: Não houve concordância entre os métodos, independente do sexo e status de peso. Para meninos com excesso de peso (EM = 4,52; p = 0,007), meninas eutróficas (EM = 6,37; p < 0,001) e meninas com excesso de peso (EM = 5,55; p < 0,001), a equação de Slaughter resultou em superestimação da gordura corporal comparada com PDA. As equações de dobras cutâneas não demonstraram validade quando comparadas ao PDA. Conclusão: As equações de dobras cutâneas de Slaughter não demonstraram concordância e validade em comparação com PDA em ambos os sexos ou status de peso. As equações de dobras cutâneas devem ser utilizadas com cautela e, sempre que possível, acompanhada de outros indicadores de composição corporal.

Physical Activity Levels in Brazilian Adolescents: A Secular Trend Study (2007-2017/18).

Only a small proportion of Brazilian adolescents practice sufficient physical activity (PA). However, it is not clear whether this proportion has been decreasing over time. This study aimed to examine the 10-year trends of sufficient PA in adolescents and to investigate differences by sex and age. Using a standard protocol, we compared two cross-sectional cohorts of adolescents aged 15 to 18 years, recruited in 2007 (n = 1040) and in 2017/18 (n = 978). Using the International Physical Activity Questionnaire-Short Form (IPAQ-SF), the adolescents reported moderate-to-vigorous PA (MVPA) performed in the last seven days. Sufficient PA was defined as engaging in at least 60 min/day of MVPA. In the subgroups, investigated by sex or age, there was an increase in the prevalence of sufficient PA. Overall, sufficient PA declined by 28.1% from 2007 to 2017/18. Boys in 2007 were more active than their 2017/18 peers, and this was equally observed in girls in 2007 compared to those in 2017/18. The findings show decreasing secular trends in sufficient PA in the investigated adolescents. Not only are public health authorities in Brazil witnessing an escalation of insufficient PA, but they are also losing ground with the most active adolescents.

Relationship between body composition and bone mass in normal-weight and overweight adolescents.

Adolescence is a period characterized by large accumulation of bone mass. Body composition is an important determinant of bone mass. This study aimed to assess the relationship of bone mass with lean mass (LM) and fat mass (FM) in normal-weight and overweight adolescents with consideration of sex, sexual maturation and physical activity covariates. A total of 118 adolescents (60 girls and 58 boys) aged between 10 and 14 years participated in the study. Individuals were classified as normal weight or overweight according to body mass index. Bone mineral density (BMD), bone mineral content (BMC), LM, and FM were measured by dual-energy X-ray absorptiometry. In normal-weight adolescents, LM (ß = 0.725, p < 0.001) and FM (ß = 0.185, p = 0.019) were associated with lumbar spine BMC, whereas in overweight adolescents only LM (ß = 0.736, p < 0.001) was associated with lumbar spine BMC. Furthermore, in the normal-weight group, FM and LM were associated with total body less head BMD (LM, ß = 0.792, p < 0.001; FM, ß = 0.257, p = 0.007) and lumbar spine BMD (LM, ß = 0.553, p < 0.001; FM, ß = 0.199, p < 0.035). In the overweight group, only LM was associated with total body less head BMD (ß = 0.682, p < 0.001) and lumbar spine BMD (ß = 0.528, p < 0.001). LM was the main predictor of bone mass in normal-weight and overweight adolescents. FM was associated with bone mass in normal-weight adolescents only. LM may be considered an important and useful marker in adolescents, when investigating bone health in this population. Activities that promote LM gain to reduce the risk of bone fractures and diseases in adulthood are recommended.

Bone Density and Bone Geometry in University Athletes From Sports With Different Levels of Impact: Simultaneous Association With Multiple Factors.

ABSTRACT: Moraes, MS, Fernandes, RA, Moreno, YMF, Pelegrini, A, and Silva, DAS. Bone density and bone geometry in university athletes from sports with different levels of impact: simultaneous association with multiple factors. J Strength Cond Res 36(11): 3113-3121, 2022-The aim of this study was to use the bone loading unit (BLU) classification to compare bone density and bone geometry of sports with different levels of impact, simultaneously controlling the multiple factors that interfere with bone metabolism in athletes. Overall, 167 university athletes (92 men) participated in the study. Bone mineral density (BMD), strength index, cross-sectional area (CSA) at the moment of inertia, section modulus (Z), CSA, neck-shaft angle (NSA), and hip axis length (HAL) were measured. Sports were categorized by level of impact, high BLU (higher impact) and moderate/low BLU (lower impact). Covariates were fat mass, lean tissue mass, training volume, time of practice, dietary supplementation, use of oral contraceptives and menstrual status. Multiple linear regression with 5% significance level ( p < 0.05) was used. In men, HAL was higher in sports with high BLU compared with those with moderate/low BLU (ß: -0.21; R2 : 0.30; p = 0.03). In women, NSA was higher in sports with moderate/low BLU compared with those with high BLU (ß: 0.31; R2 : 0.11; p = 0.02). There was no difference between BLU groups for BMD. These results persisted when the simultaneous interference of covariates was controlled. Thus, this study recommends BLU to classify sports and reinforces the importance of monitoring HAL and NSA in athletes in addition to the control of multiple factors that interfere with bone metabolism, because they influence physical performance and bone health during and after athletic life.

Results from Brazil's 2022 Report Card on Physical Activity for Children and Adolescents.

This research aims to summarize the process and results of the 2022 Report Card on Physical Activity for Brazilian children and adolescents. A group of experts led by 10 PhD researchers gathered the best possible evidence on physical activity indicators. The Report Card Brazil 2022 included the top 10 indicators of physical activity and sleep, obesity, and poor mental health variables, which made up four dimensions: (I) Daily Behaviors; (II) Settings and Sources of Influence; (III) Government Strategies and Investments; and (IV) Health Outcomes. Comprehensive searches, including peer-reviewed and gray literature searches, were performed for each indicator. Data were considered from systematic reviews, local and national surveys, websites, and official information from the Brazilian Federal Government. Grades from the indicators ranged from F (Active Play) to B (School). In addition, the results found for each indicator were Overall Physical Activity (D), Organized Sport Participation (C-), Active Transportation (C), Sedentary Behaviors (D), Sleep (C), Family and Peers (C-), Community and Environment (C), Government (D+), Physical Fitness (D+), Obesity (11.7%), and Poor Mental Health (37.8%). Successfully strategies for increasing physical activity among Brazilian children and adolescents should look at the different indicators presented in this report.

Anthropometric indicators of body fat as discriminators of low levels of cardiorespiratory fitness in adolescents.

PURPOSE: To evaluate the discriminatory power of anthropometric indicators of body fat (BF) for identifying low levels of cardiorespiratory fitness, as well as the association between cutoff points and low levels of cardiorespiratory fitness in adolescents. DESIGN AND METHODS: This is a cross-sectional study involving 1132 students (age 14-19 years). The following anthropometric variables were measured according to international standards: body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), triceps skinfold thickness (TR), subscapular skinfold (SS), suprailiac skinfold (SI), sum of triceps and subscapular skinfolds (∑TR + SS), and sum of triceps, subscapular and suprailiac skinfolds (∑TR + SS + SI). The BF percentage was calculated using the equations of Lohman (1986) (%FL), Slaughter et al. (1988) (%FS), and Boileau et al. (1985) (%FB). RESULTS: Except for TR, WC, WHtR and BMI, boys with values for the other anthropometric indicators (SS, SI, ∑TR + SS, ∑TR + SS + SI, %FL, %FS, %FB) above the cutoff point were more likely to have low levels of cardiorespiratory fitness. Girls with values for TR, ∑TR + SS, %FB and %FL above the cutoff points were more likely to have low levels of cardiorespiratory fitness. CONCLUSIONS: Anthropometric indicators had discriminatory power to identify low levels of cardiorespiratory fitness. PRACTICE IMPLICATIONS: The reported anthropometric indicators, indexes and equations can be used by healthcare professionals in clinical practice and by school teachers as a simple, fast and inexpensive alternative to identify low levels of cardiorespiratory fitness.

Relationship Between Muscle Strength, Body Composition and Bone Mineral Density in Adolescents.

Adolescence is an important period for the acquisition of bone mass, which can be enhanced by several factors. This study aimed examine the relationships of handgrip strength, free-fat mass, and fat mass with bone mineral density in adolescents. 118 adolescents (60 girls), aged 10 to 14 years, participated in the study. Information on sex, age, handgrip strength, free-fat mass, fat mass and bone mineral density were collected. Multiple linear regression analyses were conducted to examine possible relationships between bone mineral density and handgrip strength, free-fat mass and fat mass. There was a relation between handgrip strength and free-fat mass with bone mineral density in both sexes. Fat mass was correlated with bone mineral density only in girls (r= 0.314, p< 0.014). The final models, adjusted for sexual maturation, included free-fat mass (girls - ß= 0.419, p< 0.001; boys - ß= 0.455; p< 0.001) and handgrip strength (girls - ß= 0.358, p< 0.05; boys - ß= 0.325; p< 0.05) and these variables together explained 51.8% and 62.9% of the variation of bone mineral density, in girls and boys, respectively. Handgrip strength and free-fat mass were positively associated with bone mineral density. A sex-specific difference indicated that higher levels of free-fat mass are of paramount importance for both sexes.

High waist-to-height ratio and associated factors in adolescents from a city in Southern Brazil: a cross-sectional study / Razão cintura-estatura elevada e fatores associados em adolescentes de uma cidade do Sul do Brasil: um estudo transversal

ABSTRACT Objective: To verify the prevalence of abdominal obesity with the waist-to-height ratio (WHtR) and associated factors in adolescents from a city in Southern Brazil. Methods: A total of 960 adolescents (494 boys) aged 15-18 years old participated in this study. The dependent variable was WHtR; independent variables were self-reported age, economic level, sexual maturation, physical activity level, screen time, and body fat. Data were analyzed using descriptive statistics and logistic regression. Results: It was observed that 36.7% of the adolescents presented high WHtR (50.2% in girls and 23.9% in boys). Regardless of sex, adolescents with high body fat were more likely of having high WHtR (boys: Odds Ratio [OR] 29.79; 95% confidence interval [95%CI] 16.87-52.62; girls: OR 19.43; 95%CI 10.51-35.94). In girls, high WHtR was associated with age (OR 1.83; 95%CI 1.17-2.87), and in boys, with economic level (OR 2.34; 95%CI 1.01-5.45). Conclusions: One in each three adolescents has abdominal obesity. Among adolescents with high body fat, girls aged 15-16 and boys with high-income are the groups most exposed to abdominal obesity.

RESUMO Objetivo: Verificar a prevalência de obesidade abdominal, por meio da razão cintura-estatura (RCE), e fatores associados em adolescentes de uma cidade do sul do Brasil. Métodos: Participaram 965 adolescentes (499 meninos) de 15 a 18 anos. A variável dependente foi a RCE elevada e as variáveis independentes foram idade, nível econômico, maturação sexual, nível de atividade física, tempo de tela e adiposidade corporal. Os dados foram analisados por meio de estatística descritiva e regressão logística. Resultados: 36,7% dos adolescentes apresentaram RCE elevada (50,2% das meninas e 23,9% dos meninos). Independentemente do sexo, os adolescentes com adiposidade corporal elevada apresentaram maiores chances de terem RCE elevada (masculino: OR 30,91; IC95% 17,37-55,00; feminino: OR 19,18; IC95% 10,39-35,40). Nas meninas, observou-se associação da RCE elevada com idade (OR 1,88; IC95% 1,20-2,94) e, nos meninos, com nível econômico (OR 2,35; IC95% 1,01-5,46). Conclusões: Um em cada três adolescentes tem obesidade abdominal. Adolescentes com adiposidade corporal elevada, meninas de 15-16 anos e meninos de nível econômico alto são os grupos mais expostos à obesidade abdominal.

Handgrip strength and associated factors among Brazilian adolescents: A cross-sectional study.

BACKGROUND: The handgrip strength (HGS) is an indicator of muscle strength associated with several health outcomes in adolescents and adults. This cross-sectional study aimed to identify HGS levels and associated modifiable and non-modifiable risk factors in adolescents. METHODS: The study included 971 adolescents (496 boys) aged 15-18 years. The HGS was measured by a dynamometer, and the maximum value of right and left hands were summed for a total score. Age, economic status, balanced diet, physical activity, and sedentary behavior were assessed by questionnaires, while body mass index was determined by measuring body weight and height. Multiple linear regression was carried out to examine the association. RESULTS: 65.4% of the adolescents presented low levels of HGS (boys: 73.8%; girls: 56.6%). Low levels of HGS were associated with weight status and height in both sexes. In boys, low levels of HGS were associated with age, balanced diet, physical activity, and sedentary behavior. CONCLUSION: About six out of ten adolescentes presented low levels of HGS. The main predictors of low levels of HGS in boys were age, physical activity, sedentary behavior, and balanced diet, and weight status and height in both sexes.

High waist-to-height ratio and associated factors in adolescents from a city in Southern Brazil: a cross-sectional study.

OBJECTIVE: To verify the prevalence of abdominal obesity with the waist-to-height ratio (WHtR) and associated factors in adolescents from a city in Southern Brazil. METHODS: A total of 960 adolescents (494 boys) aged 15-18 years old participated in this study. The dependent variable was WHtR; independent variables were self-reported age, economic level, sexual maturation, physical activity level, screen time, and body fat. Data were analyzed using descriptive statistics and logistic regression. RESULTS: It was observed that 36.7% of the adolescents presented high WHtR (50.2% in girls and 23.9% in boys). Regardless of sex, adolescents with high body fat were more likely of having high WHtR (boys: Odds Ratio [OR] 29.79; 95% confidence interval [95%CI] 16.87-52.62; girls: OR 19.43; 95%CI 10.51-35.94). In girls, high WHtR was associated with age (OR 1.83; 95%CI 1.17-2.87), and in boys, with economic level (OR 2.34; 95%CI 1.01-5.45). CONCLUSIONS: One in each three adolescents has abdominal obesity. Among adolescents with high body fat, girls aged 15-16 and boys with high-income are the groups most exposed to abdominal obesity.

Translation and validation of the Brazilian version of the Physical Appearance Comparison Scale-Revised in college women.

Brazilian women are known to present high levels of physical appearance concerns, and data suggest they often compare themselves with others. Nevertheless, there is no validated instrument to systematically assess appearance comparisons in the Brazilian population. Thus, this study aimed to translate the Physical Appearance Comparison Scale-Revised (PACS-R) into Brazilian Portuguese and evaluate its factor structure, internal consistency, and convergent validity in Brazilian college women. The translated version into Brazilian Portuguese of the PACS-R was completed by 832 Brazilian college women and its factor structure was examined through exploratory and confirmatory factor analyses, internal consistency through McDonald's omega, and convergent validity through its associations with measures of eating disorder symptoms, internalization of appearance ideals, appearance-related sociocultural pressures, body satisfaction, and self-esteem. The results suggested an 11-item single-factor scale. The Brazilian Portuguese PACS-R showed adequate internal consistency and was significantly associated with all measures of convergent validity in the expected direction, indicating its adequate convergent validity. The Brazilian Portuguese PACS-R might be useful in the investigation of the appearance comparison among women in Brazil, as also in the study of body image and eating disorders.

Validade das medidas do tempo sentado do questionário IPAQ-versão curta em universitários brasileiros / Validity of measure of sitting time of IPAQ Questionnaire short version in undergraduate from Brazil

Os objetivos deste estudo foram estimar o nível de reprodutibilidade das medidas do tempo sen-tado do questionário International Physical Activity Questionnaire (IPAQ-versão curta) e analisar a validade concorrente dessas medidas em relação ao tempo sedentário mensurado pelo acelerômetro em universitários. Realizou-se um estudo correlacional com amostra de 61 universitários de uma instituição do ensino superior de Minas Gerais, Brasil, que autopreencheram as medidas do tempo sentado do IPAQ, intercalados por dois momentos diferentes para fins da análise de reprodutibili-dade, e usaram o acelerômetro para estimativa do tempo sedentário e emprego como padrão ouro na análise de validade concorrente. Empregou-se as análises de correlação, via coeficiente de correlação intraclasse (CCI) e gráfico de dispersão de Bland-Altman, para analisar a concordância. O nível de significância adotado foi de 5%. A média de idade foi de 21,54 anos e 62,3% foram do sexo feminino. A reprodutibilidade do tempo sentado durante um dia de semana foi moderada (CCI = 0,51; p < 0,01), enquanto em um dia do final de semana foi baixa (CCI = 0,30; p = 0,01). As diferenças médias entre o tempo sentado pelo IPAQ e o tempo sedentário pelo acelerômetro, em um dia da semana foi de -51 minutos e em um dia do final de semana foi de -64,7 minutos. Conclui-se que houve correlações e concordâncias satisfatórias tanto na reprodutibilidade quanto na comparação com a medida critério (acelerômetro) das medidas do tempo sentado mensurado pelo IPAQ para aplicação em universitários

The objectives of this study were to estimate the level of reproducibility of the sitting time measurements of the International Physical Activity Questionnaire (IPAQ-short version), and to analyze the concurrent validity of these measurements in relation the sedentary time measured by the accelerometer, in university students. A correlational study was carried out with a sample of 61 university students of a higher educa-tion institution from Minas Gerais, Brazil, who self-completed the IPAQ sitting time measurements, with interval of seven days for the purposes of the reproducibility analysis and used the accelerometer to estimate sedentary time and employment as the gold standard in the analysis of concurrent validity. The correlation analyzes via intraclass correlation coefficient (ICC) and Bland-Altman scatter plot were used to analyze the agreement. The significance level adopted was 5%. The average age was 21.54 years and 62.3% were female. The reproducibility of sitting time on a weekday was moderate (ICC = 0.51; p < 0.01), while on a weekend day it was low (ICC = 0.30; p = 0.01). The mean differences between sitting time using the IPAQ and sedentary time using the accelerometer on a weekday was -51 minutes and on a weekend was -64.7 minutes. Concluded that there were satisfactory correlations and agreements both in reproducibility and in comparison, with the criterion measure (accelerometer) of the sitting time measures measured by the IPAQ for application in university students