Estadios de Tanner y orquidometría de Prader en varones adolescentes. Estudio descriptivo transversal / Tanner stages and Prader orchidometry in male adolescents. A descriptive, cross-sectional study

Introducción. La escala de Tanner y el orquidómetro de Prader son los instrumentos más utilizados para evaluar el desarrollo puberal en los niños. La evaluación de la pubertad en la clínica solo es útil si se dispone de datos de referencia recientes y confiables de la misma población para comparar. Objetivo: evaluar la correlación entre los estadios de Tanner y el volumen testicular (VT) en adolescentes argentinos. Población y métodos. Diseño descriptivo transversal, realizado con varones saludables de 9 a 20 años de edad. Se excluyeron varones con patología urogenital y enfermedades que afectan el crecimiento testicular. La correlación entre estadios de Tanner y VT fue evaluada con pruebas no paramétricas. Resultados. Se evaluaron 367 varones con una edad de 13,8 ± 2,5 años. El VT aumentó en correlación a los estadios de Tanner (Spearman 0,943; p <0,001) con volúmenes significativamente diferentes, salvo en los estadios iniciales genital 1-2 (p 0,343) y vello púbico 1-2 (p 0,447). El 16 % (intervalo de confianza del 95 % 9,6-24,4 %; n = 17/106) de los varones peripuberales fue clasificado erróneamente basado en los estadios de Tanner. Conclusiones. Durante la pubertad masculina, el VT aumentó en correlación con los estadios de Tanner, pero no presentó diferencias significativas entre los estadios 1 y 2 de Tanner. Es fundamental el uso del orquidómetro de Prader para detectar el inicio puberal en varones.

Introduction. The Tanner scale and the Prader orchidometer are the instruments most commonly used to assess pubertal development in children. The assessment of puberty in the clinic is only useful if recent and reliable references in the same population are available for comparison. Objective: to assess the correlation between Tanner stages and testicular volume (TV) in Argentine adolescents. Population and methods. Study with a descriptive, cross-sectional design conducted in healthy boys aged 9­20 years. Male children and adolescents with urogenital conditions and disorders affecting testicular growth were excluded. The correlation between Tanner stages and TV was assessed using non-parametric tests. Results. A total of 367 male adolescents with an average age of 13.8 ± 2.5 years were assessed. TV increased in correlation to Tanner stages (Spearman: 0.943, p < 0.001) with significantly different volumes, except in the early genital 1-2 stages (p 0.343) and pubic hair 1-2 stages (p 0.447). Among peripubertal boys, 16% (95% confidence interval: 9.6­24.4%, n = 17/106) were wrongly classified based on Tanner stages. Conclusions. During male puberty, TV increased in correlation to Tanner stages, but no significant differences were observed between Tanner stages 1 and 2. Using the Prader orchidometer is critical to establish the onset of puberty in boys

Bis (2-butoxyethyl) Phthalate Delays Puberty Onset by Increasing Oxidative Stress and Apoptosis in Leydig Cells in Rats / 生物医学与环境科学（英文）

OBJECTIVE@#This study investigated the effects of bis (2-butoxyethyl) phthalate (BBOP) on the onset of male puberty by affecting Leydig cell development in rats.@*METHODS@#Thirty 35-day-old male Sprague-Dawley rats were randomly allocated to five groups mg/kg bw per day that were gavaged for 21 days with BBOP at 0, 10, 100, 250, or 500 mg/kg bw per day. The hormone profiles; Leydig cell morphological metrics; mRNA and protein levels; oxidative stress; and AKT, mTOR, ERK1/2, and GSK3β pathways were assessed.@*RESULTS@#BBOP at 250 and/or 500 mg/kg bw per day decreased serum testosterone, luteinizing hormone, and follicle-stimulating hormone levels mg/kg bw per day (P < 0.05). BBOP at 500 mg/kg bw per day decreased Leydig cell number mg/kg bw per day and downregulated Cyp11a1, Insl3, Hsd11b1, and Dhh in the testes, and Lhb and Fshb mRNAs in the pituitary gland (P < 0.05). The malondialdehyde content in the testis significantly increased, while Sod1 and Sod2 mRNAs were markedly down-regulated, by BBOP treatment at 250-500 mg/kg bw per day (P < 0.05). Furthermore, BBOP at 500 mg/kg bw per day decreased AKT1/AKT2, mTOR, and ERK1/2 phosphorylation, and GSK3β and SIRT1 levels mg/kg bw per day (P < 0.05). Finally, BBOP at 100 or 500 μmol/L induced ROS and apoptosis in Leydig cells after 24 h of treatment in vitro (P < 0.05).@*CONCLUSION@#BBOP delays puberty onset by increasing oxidative stress and apoptosis in Leydig cells in rats.@*UNLABELLED@#The graphical abstract is available on the website www.besjournal.com.

Imagem corporal e autoestima em adolescentes da rede pública estadual de Salvador-Bahia / Imagen corporal y autoestima en adolescentes de la red pública estatal de Salvador-Bahía / Body image and self-esteem in adolescents from the state public network of Salvador-Bahia

RESUMO. Objetivo: Analisar a associação entre insatisfação com a imagem corporal e autoestima de adolescentes matriculados na rede pública estadual de ensino fundamental em Salvador-Bahia. Método: Participaram deste estudo de corte transversal 860 adolescentes de 10 a 19 anos de idade, de ambos os sexos, matriculados do 7º sétimo ao 9º nono ano em 12 escolas de médio porte da rede pública estadual do ensino fundamental em turno integral, do município de Salvador, Bahia. A autoestima foi avaliada por meio da Escala de Autoestima de Rosenberg e a insatisfação com a imagem corporal pelo Body Shape Questionnaire. Dados demográficos e socioeconômicos, maturação sexual, estado antropométrico, nível de atividade física e sedentarismo foram também avaliados. A associação entre insatisfação com a imagem corporal e autoestima foi analisada pela regressão multinominal para variáveis politômicas utilizando o programa estatístico SPSS, versão 23.0. Resultados: Entre os adolescentes, 24,8% tinham moderada autoestima e 27,3% apresentaram os menores escores desse constructo. A insatisfação com a imagem corporal foi identificada em 25,2% dos adolescentes. A análise de associação revelou que adolescentes com insatisfação com a imagem corporal possuem 5,61 (IC 95% 3,08-10,24) vezes maior chance em manifestar baixa autoestima para o sexo feminino e 3,83 (IC 95% 2,03-7,25) vezes para o sexo masculino. Ainda entre as meninas, a insatisfação com a imagem corporal permaneceu associada positivamente à moderada autoestima após ajuste do modelo (OR: 2,31; IC 95% 1,21-4,41). Conclusão: Foi observada alta prevalência de níveis baixos e moderados de autoestima e que a insatisfação com a imagem corporal influenciou a baixa autoestima em ambos os sexos e a moderada entre as meninas.

RESUMEN. Objetivo: Analizar la asociación entre la insatisfacción con la imagen corporal y la autoestima en adolescentes matriculados en escuelas públicas estatales en Salvador - Bahía. Métodos: Participó en esta sección transversal un total de 860 adolescentes de 10 a 19 años, de ambos sexos, de 7º a 9º grado, matriculados en doce escuelas medianas en instituiciones públicas estatales de enseñanza a tiempo completo, en la ciudad de Salvador, Bahía. La Escala de autoestima de Rosenberg y el Body Shape Questionnaire evaluarón, respectivamente, la autoestima y la insatisfacción con la imagen corporal. También se evaluaron los datos demográficos y socioeconómicos, la maduración sexual, el estado antropométrico, el nivel de actividad física y la inactividad física. La asociación entre la insatisfacción con la imagen corporal y la autoestima se analizó mediante regresión multinominal para variables politómicas utilizando el programa estadístico SPSS Versión 23.0. Resultados: Entre los adolescentes, el 24,8% tenían una moderada autoestima y el 27,3% tenían las puntuaciones más bajas de este constructo. La insatisfacción con la imagen corporal se identificó en el 25,2% de los adolescentes. El análisis de asociación reveló que las chicas y los chicos con la insatisfacción con la imagen corporal tenían, respectivamente, 5,61 (IC 95% 3,08 - 10,24) veces y 3,83 (IC 95% 2,03 - 7,25) veces en tener más chances de tener baja autoestima. También entre las chicas, la insatisfacción con la imagen corporal se mantuvo positivamente asociada con uma moderada autoestima después del ajuste del modelo (OR: 2,31; IC del 95%: 1,21 a 4,41). Conclusión: Se observó una alta ocurrencia de baja y moderada autoestima y que la insatisfacción con la imagen corporal influyó en la baja autoestima en ambos sexos y en la moderada autoestima entre las chicas.

ABSTRACT. Objective: To analyze an association between dissatisfaction with body image and self - esteem of adolescents enrolled in the public elementary school system in Salvador - Bahia. Methods: Participated in this cross-sectional study 860 adolescents aged 10 to 19, of both sexes from the 7th to the 9th year, enrolled in twelve medium-sized schools of the public elementary school system in full shift, in the city of Salvador, Bahia. Self-esteem was assessed through the Rosenberg Self-esteem Scale and body image dissatisfaction by the Body Shape Questionnaire. Demographic and socioeconomic data, sexual maturation, anthropometric status, physical activity level and sedentary lifestyle were evaluated. The association between dissatisfaction with body image and self-esteem was analyzed by multinominal regression for polytomic variables using the statistical program SPSS Version 23.0. Results: Among the adolescents, 24.8% had moderate self-esteem and 27.3% had the lowest scores of this construct. Body image dissatisfaction was identified in 25.2% of the adolescents. The association analysis revealed that adolescents with body image dissatisfaction have 5.61 (95%ci 3.08-10.24) times greater chance of manifesting low self-esteem for females and 3.83 (95%ci 2.03-7.25) times for males. Still among girls, dissatisfaction with body image remained positively associated with moderate self-esteem after adjusting the model (OR: 2.31; 95%ci 1.21-4.41). Conclusion: It was concluded that the prevalence of low and moderate self-esteem was high, and dissatisfaction with body image influenced low self-esteem in both sexes and a moderate among girls.

A classification of genes involved in normal and delayed male puberty / 亚洲男科学杂志(英文版)

Puberty is a pivotal biological process that completes sexual maturation to achieve full reproductive capability. It is a major transformational period of life, whose timing is strongly affected by genetic makeup of the individual, along with various internal and external factors. Although the exact mechanism for initiation of the cascade of molecular events that culminate in puberty is not yet known, the process of pubertal onset involves interaction of numerous complex signaling pathways of hypothalamo-pituitary-testicular (HPT) axis. We developed a classification of the mechanisms involved in male puberty that allowed placing many genes into physiological context. These include (i) hypothalamic development during embryogenesis, (ii) synaptogenesis where gonadotropin releasing hormone (GnRH) neurons form neuronal connections with suprahypothalamic neurons, (iii) maintenance of neuron homeostasis, (iv) regulation of synthesis and secretion of GnRH, (v) appropriate receptors/proteins on neurons governing GnRH production and release, (vi) signaling molecules activated by the receptors, (vii) the synthesis and release of GnRH, (viii) the production and release of gonadotropins, (ix) testicular development, (x) synthesis and release of steroid hormones from testes, and (xi)the action of steroid hormones in downstream effector tissues. Defects in components of this system during embryonic development, childhood/adolescence, or adulthood may disrupt/nullify puberty, leading to long-term male infertility and/or hypogonadism. This review provides a list of 598 genes involved in the development of HPT axis and classified according to this schema. Furthermore, this review identifies a subset of 75 genes for which genetic mutations are reported to delay or disrupt male puberty.

Association of sex, sexual maturation, age group, economic class, and nutritional status with the different cutoff points of screen time in adolescents / Associação entre sexo, maturação sexual, faixa etária, classe econômica e estado nutricional com os diferentes pontos de corte do tempo de tela em adolescentes

Abstract Objectives: to estimate the prevalence of adolescents' screen time in three different scenarios and possible associations with gender, sexual maturation, age group, economic class, and nutritional status. Methods: a cross-sectional study conducted with a representative sample of 3,979 adolescents from Greater Curitiba. Screen time (television, computer, and video game) was self-reported and categorized as ≤2h/day, >2 to ≤4h/day, and >4h/day. Ordinal logistic regression tested the associations. Results: the sample consisted of adolescents of 14.60±1.88 years old, most girls (51.2%). The prevalence of screen time >4h/day was 89.3%. Girls (OR=0.61; CI95%=0.49-0.76) and the older age groups ("14 to 16 years" OR=0.29; CI95%=0.22-0.39, and "17 to 19 years" OR=0.11; CI95%=0.08-0.16) were less likely to be in the groups of higher screen time. Conclusions: screen time above four hours seems to be the most prevalent among adolescents. Older girls and teens are less likely to have higher screen time.

Resumo Objetivos: estimar a prevalência de tempo de tela de adolescentes em três diferentes cenários e possíveis associações com sexo, maturação sexual, faixa etária, classe econômica e estado nutricional. Métodos: estudo transversal realizado com amostra representativa de 3.979 adolescentes da Grande Curitiba. O tempo de tela (televisão, computador e videogame) foi autorrelatado e categorizado em ≤2h/dia, >2 a ≤4h/dia e >4h/dia. A regressão logística ordinal testou as associações. Resultados: amostra com idade média de 14,60±1,88 anos, formada por 51,2% de meninas.A prevalência de tempo de tela >4h/dia foi de 89,3%. Meninas (OR=0,61; IC95%=0,49-0,76) e os grupos de idade mais velhos ("14 a 16 anos" OR=0,29; IC95%=0,22-0,39 e "17 a 19 anos" OR=0,11; IC95%=0,08-0,16) eram menos propensos a estar nos grupos de maior tempo de tela. Conclusões: o tempo de tela acima de quatro horas parece ser o mais prevalente entre os adolescentes. Meninas e adolescentes mais velhos são menos propensos ao maior tempo de tela.

Excesso de adiposidade corporal periférica, central e geral em adolescentes de uma cidade do sul do Brasil / Excess of peripheral, central and general body adiposity in adolescents in a city in southern Brazil

Objetivo: estimar a prevalência e analisar os fatores sociodemográficos e de estilo de vida associados ao excesso de adiposidade periférica, central e geral em adolescentes. Método: estudo transversal, realizado na cidade de São José/Santa Catarina, Brasil, com 1.132 adolescentes (14-19 anos). As variáveis dependentes foram adiposidade periférica (dobra cutânea [DC] do tríceps), central (DC subescapular) e geral (presença de adiposidade periférica e central), classificadas pelo percentil 90 do Centers for Disease Control and Prevention. As variáveis independentes foram nível econômico, atividade física (AF) e hábitos alimentares, obtidos por meio de questionários. A maturação sexual foi avaliada segundo critérios de Tanner. Resultados: o excesso de adiposidade periférica, central e geral, foi de 11,1%, 10,3% e 7,1%, respectivamente, para adolescentes do sexo masculino e, 13,1%,14,7% e 9,8%, respectivamente, para adolescentes do sexo feminino. Os adolescentes do sexo masculino com baixos níveis de AF apresentaram maiores chances de excesso de adiposidade periférica (OR:2,32; IC95%: 1,09-5,37). As adolescentes do sexo feminino, no estágio maturacional pós-púbere apresentaram maiores chances de excesso de adiposidade central (OR:3,80; IC95%:2,25-6,41) e geral (OR:3,31; IC95%:1,79-6,10), e aquelas que estudavam no período noturno apresentaram menores chances de ter excesso de adiposidade central (OR:0,35; IC95%:0,18-0,71) e geral (OR:0,43; IC95%:0,19-0,95). Conclusão: o excesso de adiposidade se fez presente, sendo que o baixo nível de AF para os adolescentes do sexo masculino, o estágio maturacional póspúbere e o turno de estudo diurno foram fatores associados ao excesso de adiposidade para as adolescentes do sexo feminino. (AU)

Objective: to estimate the prevalence and to analyze sociodemographic and lifestyle factors associated with excess peripheral, central and general adiposity in adolescents. Method: a cross-sectional study, conducted in the city of São José/Santa Catarina, Brazil, with 1,132 adolescents (14-19 years old). The dependent variables were peripheral adiposity (tríceps skinfold), central (subscapular skinfold) and general (presence of peripheral and central adiposity), classified from the 90th percentile of the Centers for Disease Control and Prevention curve. The independent variables were economic level, physical activity (PA) and eating habits, obtained through questionnaires. The sexual maturation was evaluated according to Tanner criteria. Results: the excess of central and general peripheral adiposity was 11.1%, 10.3% and 7.1%, respectively, for male adolescents and 13.1%, 14.7% and 9.8%, respectively, for adolescent females. Males with low PA l evels presented higher odds of excess peripheral adiposity (OR: 2.32; 95% CI: 1.09-5.37). The female adolescents in the post-pubertal maturational stage presented higher odds of excess central adiposity (OR: 3.80; 95% CI: 2.25-6.41) and general adiposity (OR: 3.31; 95% CI: 1.79-6.10), and those who studied at night had a lower chance of having excess central adiposity (OR: 0.35, 95% CI: 0.18-0.71) and general adiposity (OR: 0.43; 95% CI: 0.19-0.95). Conclusion: the excess of adiposity was present and that the low level of PA for the male adolescents, the post-pubertal maturational stage and the daytime shift were factors associated with excess adiposity for female adolescents. (AU)

Perceived causes of change in Nigerian adolescent sexual risk behaviour ­ Results from semi-structured mobile instant messaging interviews

The study explores the perceived causes of change in sexual risk behaviour among Nigerian adolescents over the past years. By embedding the results into a theoretical context, the study aims to further develop interventions targeting adolescent sexual health. To do so, 23 semi-structured interviews are conducted through the mobile-instant-messaging tool WhatsApp. The interview sample consists of both female and male adolescents and adults from different regions in Nigeria. The interviews are conducted as simultaneous chats and analysed based on the qualitative content analysis approach. Respondents perceive a multitude of different factors as causes of change in sexual risk behaviour among Nigerian adolescents. They can be categorised into (1) individual actors, (2) structural factors, and (3) socio-cultural factors. Interrelations between the different factors can partly be observed. The other factors are mostly modifiable and can therefore contribute to reducing adolescent SRB.

Aspectos reproductivos de la raya látigo Hypanus longus (Garman, 1880) de los desembarques de la pesca artesanal en el Pacífico de Guatemala / Reproductive aspects of the longtail stingray Hypanus longus (Garman, 1880) from the landings of the artisanal fishery in the Pacific of Guatemala

La raya látigo Hypanus longus, ha pasado de ser una especie de captura incidental a una especie objetivo en la pesca artesanal del Pacífico de Guatemala. Esta actividad es realizada sin considerar criterios biológicos esenciales para su aprovechamiento sostenible. Aunado a ello, H. longus es una especie sensible, presentando características biológicas como: madurez sexual tardía, ciclos reproductivos largos y baja fecundidad. El presente estudio contribuye al conocimiento de la biología reproductiva de la raya látigo. Durante mayo de 2019 a marzo de 2020 se realizaron 11 muestreos de los desembarques de la pesca artesanal en la comunidad de Sipacate, Escuintla, en cada muestreo se registró el ancho de disco (AD), el peso, sexo y estado de maduración sexual de H. longus. En total se registraron 336 organismos, que presentaron una proporción sexual de 1:1, un AD para hembras de M = 82.33 cm, DS = 22.24 y de M = 76.91 cm, DS = 11.86 para machos. A partir de las evaluaciones externas e internas de los aparatos reproductores se determinó la talla de madurez sexual (L50), siendo de 88.2 y 79.3 cm AD para hembras y machos respectivamente. Finalmente, este estudio evidencio que el 65.68% de hembras y el 52.10% de machos son capturados por debajo de la L50, por lo cual se recomienda elaborar e implementar estra-tegias o medidas tendientes a la regulación de las prácticas pesqueras o artes de pesca que permitan la captura de organismos mayores a 95 cm de AD.

The whip ray Hypanus longushas gone from being a bycatch species to a target species in artisanal fisheries in the Pacific of Guatemala. This activity is carried out without considering essential biological criteria for its sustainable use. In addition, H. longusis a sensitive species, presenting biological characteristics such as late sexual maturity, long reproductive cycles and low fecundity. The present study contributes to the knowledge of the reproductive biology of the whip ray. During May 2019 to March 2020, 11 samplings were conducted from artisanal fishery landings in the community of Sipacate, Escuintla, in each sampling the disc width (AD), weight, sex and sexual maturation stage of H. longus were recorded. A total of 336 organisms were recorded, which pre-sented a sex ratio of 1:1, with a female AD of M = 82.33 cm, SD = 22.24 and M = 76.91 cm, SD = 11.86 for males. From the external and internal evaluations of the reproductive apparatus, the size at sexual maturity (L50) was determined to be 88.2 and 79.3 cm AD for females and males, respectively. Finally, this study showed that 65.68% of females and 52.10% of males are caught below L50, so it is recommended to develop and implement strategies or measures to regulate fishing practices or fishing gear that allow the capture of organisms larger than 95 cm AD.

Reproductive biology of seven fish species of commercial interest at the Ramsar site in the Baixada Maranhense, Legal Amazon, Brazil

The purpose of this study is to determine the parameters of the reproductive biology of seven commercial species at the Ramsar Site of the Baixada Maranhense to support fisheries management measures. The collections were carried out between 2012 and 2016. The reproductive period, sex ratio, weight-length relationship and first sexual maturity were evaluated for seven species of commercial importance. The sex ratio showed that females are predominant for all species, except for Plagioscion squamossissimus. The weight-length relationship indicated a greater investment in weight for Cichla monoculus and Hassar affinis, and a greater investment in length for Hoplias malabaricus, Plagioscion squamosissimus, Prochilodus lacustris, Pygocentrus nattereri, and Schizodon dissimilis. The reproductive activity of the species was predominant in the rainy season, but C. monoculus, H. malabaricus and P. lacustris showed the ability to reproduce in both seasons. As management measures for the region, it is suggested a change in the closed fishing season established by IBAMA, from December 1 to April 30, to ensure the protection of all commercial species in this study.(AU)

Este estudo teve como objetivo determinar os parâmetros da biologia reprodutiva de sete espécies comerciais no Sítio Ramsar da Baixada Maranhense, para apoiar medidas de manejo pesqueiro. As coletas foram realizadas entre 2012 e 2016, com um ano de coleta para cada espécie. Foram avaliados o período reprodutivo, a razão sexual, a relação peso-comprimento e a primeira maturidade sexual para sete espécies de importância comercial. A razão sexual mostrou que as fêmeas são predominantes para todas as espécies, exceto para Plagioscion squamossissimus. A relação peso-comprimento indicou um maior investimento em peso para Cichla monoculus e Hassar affinis, e um maior investimento em comprimento para Hoplias malabaricus, Plagioscion squamosissimus, Prochilodus lacustris, Pygocentrus nattereri e Schizodon dissimilis. A atividade reprodutiva das espécies foi predominante na estação chuvosa, mas C. monoculus, H. malabaricus e P. lacustris mostraram capacidade de se reproduzir nas duas estações. Como medidas de manejo para a região, sugere-se uma mudança do período de defeso, estabelecida pelo IBAMA, de 1 de dezembro a 30 de abril, para garantir a proteção de todas as espécies comerciais.(AU)

Reproductive cycle of native viviparous fish species (Actinopterygii: Cyprinodontiformes: Goodeidae) in a subtropical Mexican lake

Reproductive tactics and strategies contribute to the persistence and maintenance of long-term populations in fish species. Members of the subfamily Goodeinae are a group of small-bodied freshwater fish with specialized reproduction (viviparity-matrotrophy). They are found in the highlands of central Mexico, most of them endemic. The aim of this study was to conduct a comprehensive investigation to evaluate the annual reproductive cycle of seven species of goodeines (splitfins). We carried out our study in the subtropical Lake Zacapu, Mexico, with bi-monthly sampling from May 2019 to March 2020. We obtain the fertility, size at first maturity (L50), sex ratio, and gonadosomatic index. Our result shows that populations of goodeines have high fertility compared to other populations of the same species in other aquatic systems and also to other species of goodein. We found that males mature at smaller sizes than females, the observed proportion of females was greater than males in all the goodeines. Lake Zacapu goodeines have two reproductive peaks, one in spring (April to June) and another in fall (September to November). These tactics (fertility rates, sex ratio, reproductive period) and strategies (viviparity-matrotrophy) favor reproductive success in this environmentally stable subtropical lake in the highlands of Mexico.(AU)

Las tácticas y estrategias reproductivas contribuyen a la persistencia y el mantenimiento de las poblaciones a largo plazo en especies de peces. Miembros de la subfamilia Goodeinae son un grupo de peces de agua dulce con reproducción especializada (viviparidad-matrotrofia). Se encuentran en el centro de México, la mayoría de ellos endémicos. El objetivo de este estudio fue realizar una investigación integral para evaluar el ciclo reproductivo anual de siete especies de goodeines o mexclapiques. Realizamos nuestro estudio en el lago subtropical de Zacapu, México, con muestreo bimestral de mayo de 2019 a marzo de 2020. Nuestros resultados muestran que las poblaciones de goodeines tienen una alta fertilidad en comparación con otras poblaciones de la misma especie en otros sistemas acuáticos y también con otras especies de goodeines. Encontramos que los machos maduran en tamaños más pequeños que las hembras, la proporción observada de hembras fue mayor que los machos en todas las goodeines. Los goodeines del lago Zacapu tienen dos picos reproductivos, uno en primavera (abril a junio) y otro en otoño (septiembre a noviembre). Estas tácticas (fertilidad, proporción de sexos, período reproductivo) y estrategias (viviparidad-matrotrofia) favorecen el éxito reproductivo en este lago subtropical ambientalmente estable en el altiplano de México.(AU)

Normative values of handgrip strength in adolescents according to chronological age and sexual maturation

Abstract Aim: Handgrip strength is considered an important health indicator. It is extremely important to establish normative values so that the handgrip strength is correctly interpreted in adolescents. The present study aims to establish normative values of handgrip strength (HGS) for adolescents, according to chronological age and sexual maturation. Methods: Data from three large projects carried out in Florianopolis and São José, Santa Catarina were used, corresponding to a sample of 2,637 adolescents aged 14 to 19 years old of both sexes (1,428 girls). The HGS of the right and left hands was measured by a manual dynamometer, and total HGS being defined by the sum of the left hand and the right-hand strength. Sexual maturation was determined by the development of pubic hair. The percentiles 3, 10, 15, 25, 50, 75, 85, 90, and 97 were calculated for the right, left, and total HGS. The percentile ranges < p15 (low), p15-p85 (normal) and > p85 (high) were used. ANOVA and Kruskal-Wallis tests were applied. Results: In boys, the mean total HGS ranged from 67.5 ± 16.5 to 86.9 ± 21.8 (p < 0.001) and 74.3 ± 17.5 to 82.2 ± 17.8 (p < 0.001) for age and sexual maturation, respectively, while in girls the mean HGS total ranged from 48.8 ± 11.3 to 56.4 ± 16.0 (p = 0.127) and 47.8 ± 10.6 to 54.3 ± 12.3 (p < 0.001). Conclusion: Reference values established by the percentile score, can be used to identify adolescents with better athletic condition and can be useful for prescribing exercises.

Referencias internacional y nacional, su uso en el estudio del crecimiento y la maduración física / International and national references, their use in the study of growth and physical maturation

Los factores genéticos y ambientales interactúan durante todo el crecimiento. La talla final adulta, el ritmo o tempo de crecimiento y maduración, así como la maduración sexual, esquelética y dental, tienen una transmisibilidad entre 41 y 71%. El estirón puberal ocurre un año antes en africanos que en europeos y los asiáticos son intermedios. Esta heterogeneidad puberal dificulta el uso de una referencia internacional en esta etapa, aunque su valor al permitir la comparabilidad entre poblaciones es indiscutible, así como el hecho que no todos los países pueden desarrollar sus propias referencias. En la Región Latinoamericana, Argentina, Cuba y Venezuela desarrollaron referencias hace muchos años y recientemente, Colombia, Ecuador y Perú. En Venezuela, se realizó el Estudio Nacional de Crecimiento y Desarrollo Humano (ENCDH) y el Estudio Longitudinal de Caracas (ELAMC) para establecer patrones de referencia, relevantes debido a la maduración más temprana y a las diferencias significativas en crecimiento y maduración con los anglosajones. Así mismo se elaboró el Atlas de Maduración Ósea del Venezolano y se han construido Curvas para uso Clínico integrando ambos estudios. Debido a la disparidad en el uso de referencias- internacionales y nacionalesse está planificando un estudio multicéntrico, denominado PRONNA, de la línea de investigación sobre Crecimiento y Desarrollo en Niños y Adolescentes (CDNNA) del Grupo Transición Alimentaria y Nutricional (grupo TAN) para la escogencia definitiva de las referencias a ser usadas(au)

Genetic and environmental factors interact during growth. Final height, tempo of growth, sexual, skeletal and dental maturation have between 41 and 71% heritability. The puberal spurt occurs one year earlier in Africans than in European descendants, Asiatic are intermediate. This pubertal heterogeneity difficult the use of an international reference during this period, although its importance in the comparability of prevalences is unique, as well as the fact that many countries are unable to develop their own references. In the Latin American Region, Argentina, Cuba and Venezuela have long--standing references, Colombia, Ecuador and Perú only recently. In Venezuela, due to the earlier maturation and differences from puberty onwards with anglosaxons, the National Growth and Development Study and the Caracas Longitudinal Study were developed in order to obtain growth charts. Both studies integrated for Clinical Use dual use charts: an Atlas for Bone Maturity Asessment is also available. Due to the multiple use of references (national as well as international) a multicenter national study-PRONNA- is being planned in order to decide which reference is most adequate. This is part of the Growth and Development Research line of study of TAN Group (Food and Nutritional Transition Group)(AU)

Gonadal maturation in Pseudoplatystoma metaense x Leiarius marmoratus hybrids, (Siluriformes: Pimelodidae) / Maduración gonadal en híbridos de Pseudoplatystoma metaense x Leiarius marmoratus (Siluriformes: Pimelodidae)

SUMMARY: Establishing guidelines for responsible management in fish production systems requires knowledge of the basic biology of the fish to be raised. The objective of this work was to determine the reproductive capacity of hybrids produced from the crossing of females of Pseudoplatystoma metaense with males of Leiarius marmoratus. Males presented a digitiform, unrestricted spermatogonial testicle containing caudal digits producing glycoproteins that do not form a seminal vesicle. It was possible to find free sperm in the lumen of the tubules and in the ducts. The ovary of the females was found to be saccular and synchronous with at least three groups of oocytes. In the first year of life, only oogonia up to previtellogenic oocytes (cortical alveolus 284.9 ± 35.7 mm in diameter) were found. After the second year vitellogenic oocytes 730 ± 3.78 mm in diameter were observed. The events of gonadal development of the hybrids indicate that they are gonochoric, synchronic animals. The maturation peaks in the high-water season, overlapping with the parental species. Therefore, the escape of hybrids from fish cultures to the rivers may increase the risk of crosses, gene introgression, or diminution of the reproductive capacity of the pure species.

RESUMEN: El establecimiento de pautas para la gestión responsable en los sistemas de producción de peces requiere el conocimiento de la biología básica de los peces a criar. El objetivo de este trabajo fue determinar la capacidad reproductiva de los híbridos producidos por el cruce de hembras de Pseudoplatystoma metaense con machos de Leiarius marmoratus. Los machos presentaron un testículo espermatogonial digital no restringido que contiene dígitos caudales que producen glucoproteínas que no forman una vesícula seminal. Fue posible encontrar esperma libre en la luz de los túbulos y en los conductos. Se encontró que el ovario de las hembras era sacular y sincrónico con al menos tres grupos de ovocitos. En el primer año de vida, solo se encontraron oogonia hasta ovocitos previtelogénicos (alvéolo cortical de 284,9 ± 35,7 mm de diámetro). Después del segundo año, se observaron ovocitos vitelogénicos de 730 ± 3,78 mm de diámetro. Los eventos de desarrollo gonadal de los híbridos indican que son animales sincrónicos gonocóricos. La maduración alcanza su punto máximo en la temporada de aguas altas, superponiéndose con las especies parentales. Por lo tanto, el escape de híbridos de cultivos de peces a los ríos puede aumentar el riesgo de cruces, introgresión genética o disminución de la capacidad reproductiva de las especies puras.

Reproductive biology, morphology, and morphometry of ovaries and oviducts of Trachemys scripta elegans in Brazilian Cerrado / Biologia reprodutiva, morfologia e morfometriade ovários e ovidutos de Trachemys scripta elegans no Cerrado Brasileiro

Although Trachemys scripta elegans is an exotic species popular as a pet in Brazil, studies on reproductive biology and capacity are non-existent in the Brazilian Cerrado. This study analyzed ovarian and oviduct characteristics and the egg production capacity of T. scripta elegans grown in this biome. The findings will associate with the size of the specimens and the sexual maturity, aiming at comparisons with native and exotic populations, as well as interspecific and contributing to the understanding of its impact on the invaded ecosystems and the establishment of eradication programs. Thus, 39 females had evaluated the body biometry and the morphology and morphometry of the ovaries and oviducts. G2 (N=20): with Class I (>5-10mm) follicles, with Class I and Class II (>10-fold) follicles, 25mm) and G3 (N=9) with Class I, Class II and Class III (>25mm) follicles. Analysis of variance, Scott-Knott's test, and Pearson's correlation analysis showed that there was no significant difference between the groups in body biometry; in the mean gonadosomatic index and gonadal morphometry, only the width of the oviducts in the right antimer and the mass and width in the left antimer were higher in G3, the only one that presented eggs. There was positive and harmonic development between body mass, carapace, and plastron, and gonadal growth occurred concomitantly with body growth, indicating a higher reproductive potential and a positive relationship between the size of the litter and the female litter. The gonadosomatic index proved to be an excellent reproductive indicator, and the ovarian evaluation was a better indicator of sexual maturity than the maximum carapace length. Ovaries were irregular structures, without delimitation between the cortical and medullary regions and filled with vitelogenic follicles of different diameters, atresic follicles, and corpora lutea, which reflected the ovarian complexity of the species and the presence of follicular hierarchy. In the scarce stroma, two germinative beds were observed per ovary and the presence of gaps very close to the follicles and associated with the blood vessels. Analysis of gonadal tissue revealed three types of oocytes according to cytoplasmic characteristics: homogeneous, vesicular or vesicular in the cortex with apparent granules. Oviducts were functional and separated, joining only in the final portion to form the cloaca and subdivided into infundibulum, tuba, isthmus, uterus, and vagina. The structure of the uterine tube was composed of serosa, muscular and mucous, which was full of glands. The presence of eggs in the oviducts indicated that the specimens can reproduce in the Brazilian Cerrado. This study provides necessary and relevant information on the reproductive biology and capacity of T. scripta elegans in the Brazilian Cerrado and can contribute to the understanding of its impact on the invaded ecosystems and the establishment of eradication programs. The extraction of females with capacity can reduce the annual reproductive yield of the species and decrease its effect on local biodiversity.(AU)

Embora Trachemys scripta elegans seja uma espécie exótica popular como animal de estimação no Brasil, estudos sobre biologia e capacidade reprodutivas são inexistentes no Cerrado brasileiro. Este estudo analisou características ovarianas e do oviduto e a capacidade de produção de ovos em T. scripta elegans criadas neste bioma, correlacionando estes achados ao tamanho dos espécimes e a maturidade sexual, visando comparações com populações nativas e exóticas, bem como interespecíficas e contribuir para a compreensão de seu impacto nos ecossistemas invadidos e com o estabelecimento de programas de erradicação. Assim, 39 fêmeas tiveram avaliadas a biometria corporal e a morfologia e morfometria dos ovários e ovidutos. De acordo com o tamanho dos folículos ovarianos as fêmeas foram separadas em G1 (N= 10): com folículos Classe I (>5-10 mm), G2 (N= 20): com folículos Classe I e Classe II (>10-25 mm) e G3 (N= 9) com folículos Classe I, Classe II e Classe III (>25 mm). À análise de variância, teste de Scott-Knott e à análise de correlação de Pearson verificou-se que não houve diferença significativa entre os grupos na biometria corporal; no índice gonadossomático médio e na morfometria gonadal, apenas a largura dos ovidutos no antímero direito e a massa e a largura no antímero esquerdo foram maiores no G3, o único que apresentou ovos. Houve desenvolvimento positivo e harmônico entre massa corporal, carapaça e plastrão e o crescimento gonadal ocorreu concomitante ao crescimento corporal, indicando maior potencial reprodutivo e relação positiva entre o tamanho da ninhada de ovos e o da fêmea. O índice gonadossomático mostrou-se um bom indicador reprodutivo e a avaliação ovariana um melhor indicador da maturidade sexual que o comprimento máximo da carapaça. Ovários foram estruturas irregulares, sem delimitação entre a região cortical e medular e repletos de folículos vitelogênicos de diferentes diâmetros, folículos atrésicos e corpos lúteos, que refletiram a complexidade ovariana da espécie e a presença de hierarquia folicular. No estroma escasso foram observados dois leitos germinativos por ovário e a presença de lacunas muito próximas aos folículos e associadas aos vasos sanguíneos. A análise do tecido gonadal revelou três tipos de oócitos de acordo com as características do citoplasma: homogêneo, vesicular ou vesicular no córtex com grânulos aparentes. Ovidutos eram funcionais e separados, unindo-se apenas na porção final para formar a cloaca e subdividiam-se em infundíbulo, tuba uterina, istmo, útero e vagina. A estrutura da tuba uterina era constituída de serosa, muscular e mucosa, a qual era repleta de glândulas. A presença de ovos nos ovidutos indicou que os espécimes podem se reproduzir no cerrado brasileiro. Este estudo fornece informações básicas e relevantes da biologia e capacidade reprodutivas de T. scripta elegans no Cerrado brasileiro e pode contribuir com a compreensão de seu impacto nos ecossistemas invadidos e com o estabelecimento de programas de erradicação, uma vez que a extração de fêmeas com capacidade reprodutiva pode contribuir com a diminuição do rendimento reprodutivo anual da espécie e diminuir seu efeito sobre a biodiversidade local.(AU)

Effect of prednisolone on linear growth in children with nephrotic syndrome / Efeito da prednisolona sobre o crescimento linear em crianças com síndromenefrótica

Abstract Objective This study aims at determining the relationship between prednisolone cumulative dose and linear growth in pre-pubertal children with idiopathic nephrotic syndrome. Method This cross-sectional study was conducted on all children with idiopathic nephrotic syndrome registered to the pediatric nephrology department at the main referral children's hospital in Southwestern Iran. Inclusion criteria included age (males <12 years; females <10 years), >6 months of use, and the minimum prednisolone cumulative dose of 152 mg/kg. The exclusion criteria were individuals who had entered puberty or had other diseases affecting linear growth. Based on the prednisolone cumulative dose of ≥550 mg/kg (four or more relapses), the children were divided into two groups. All data regarding age, height, and weight at disease onset and the last visit, bone age, and the parents' height were collected. Secondary variables including mid-parental target height and predicted adult height were also calculated. Height data were compared between the different rates of relapse. Results A total of 97 children (68% male) were enrolled. Their post-treatment mean height Z-score was less than that obtained before treatment (−0.584 vs. −0.158; p = 0.001). Subjects with higher prednisolone cumulative doses were found to have more reduction in height Z-score (p = 0.001). Post-treatment height prediction also showed less growth potential compared to pre-treatment target height (p = 0.006). Thirty-three children (34.4%) had four or more relapses, among whom more mean-height Z-score decreases were found compared to those with less-frequent relapses (−0.84 vs. −0.28; p = 0.04). Conclusion This study showed the negative effect of cumulative dosages of prednisolone on linear growth, which was greater in children with four or more relapses.

Resumo Objetivo Determinar a relação entre a dose cumulativa de prednisolona e o crescimento linear em crianças pré-púberes com síndrome nefrótica idiopática. Método Estudo transversal conduzido em todas as crianças com síndrome nefrótica idiopática registradas no departamento de nefrologia pediátrica no principal hospital infantil para encaminhamento no sudoeste do Irã. Os critérios de inclusão incluíram idade (meninos < 12 anos; meninas < 10 anos), > 6 meses e a dose cumulativa de prednisolona mínima de 152 mg/kg. Os critérios de exclusão foram indivíduos que entraram na puberdade ou tinham outras doenças que afetam o crescimento linear. Com base na dose cumulativa de prednisolona de ≥ 550 mg/kg (≥ 4 recidivas), as crianças foram divididas em dois grupos. Foram coletados todos os dados relacionados a idade, estatura e peso no início da doença e na última visita, idade óssea e estatura dos pais. Também foram calculadas as variáveis secundárias, inclusive estatura-alvo e estatura adulta prevista. Os dados de estatura foram comparados entre as diferentes taxas de recidivas. Resultados Foram inscritas 97 crianças (68% do sexo masculino). Seu escore z de estatura média pós-tratamento foi inferior ao obtido antes do tratamento (−0,584 em comparação com −0,158; p = 0,001). Os indivíduos com maiores doses cumulativas de prednisolona mostraram maior redução no escore z para estatura (p = 0,001). A estatura pós-tratamento também foi preditiva de menor potencial de crescimento em comparação com a estatura-alvo pré-tratamento (p = 0,006); 33 crianças (34,4%) apresentaram ≥ 4 recidivas, entre as quais foram encontradas mais reduções médias no escore z para estatura em comparação com as recidivas menos frequentes (−0,84 em comparação com −0,28; p = 0,04). Conclusão Este estudo mostrou o efeito negativo das doses cumulativas de prednisolona sobre o crescimento linear, que foi maior em crianças com ≥ 4 recidivas.

Height and sexual maturation in girls with juvenile idiopathic arthritis / Estatura e maturação sexual em meninas com artrite idiopática juvenil

Abstract Objective To evaluate height, sexual maturation, and the difference between final and expected height in girls with juvenile idiopathic arthritis and no glucocorticoid treatment for at least six months, as compared to a group of healthy girls. Methods This cross-sectional study involved 44 girls with juvenile idiopathic arthritis, diagnosed according to the International League of Associations for Rheumatology criteria, and 59 healthy controls aged between 8 and 18 (incomplete) years with no comorbid chronic diseases. Demographic data were collected from all participants, and disease and treatment variables were compiled for the patient group. Anthropometric measurements were converted into Z-scores based on World Health Organization standards. Sexual maturation was classified according to Tanner stages. Results Body mass index and height Z-scores were lower in girls with juvenile idiopathic arthritis as compared to control participants. These values differed significantly in Tanner stage II. Three (6.8%) girls with juvenile idiopathic arthritis had height-for-age Z-scores <−2 (short stature). Girls with polyarticular juvenile idiopathic arthritis and higher cumulative glucocorticoid doses were significantly more likely to present with short stature. The percentage of prepubertal girls in the juvenile idiopathic arthritis group was significantly higher than that observed in the control group, (p = 0.012). Age of menarche, adult height, and the difference between actual and expected height did not differ between groups. Conclusion These findings suggest that even six months after the suspension of glucocorticoid treatment, children with polyarticular/systemic juvenile idiopathic arthritis subtypes are still susceptible to low height and delayed puberty.

Resumo Objetivo Avaliar a estatura, maturação sexual e a diferença entre a estatura final e a esperada em meninas com artrite idiopática juvenil (AIJ) sem tratamento com glicocorticoides por pelo menos seis meses, em comparação com um grupo de meninas saudáveis. Métodos Este estudo transversal avaliou 44 meninas com artrite idiopática juvenil, diagnosticadas de acordo com os critérios da International League of Associations for Rheumatology e 59 controles saudáveis, entre oito e 18 anos (incompletos) sem comorbidades por doenças crônicas. Os dados demográficos foram coletados de todos os participantes e as variáveis de doença e tratamento foram compiladas para o grupo de pacientes. As medidas antropométricas foram convertidas em escores-z com base nos padrões da Organização Mundial da Saúde. A maturação sexual foi classificada de acordo com os estágios de Tanner. Resultados Índice de massa corporal e escores-z de estatura foram menores em meninas com artrite idiopática juvenil em comparação com os participantes-controle. Esses valores diferiram significativamente no estágio II de Tanner. Três (6,8%) meninas com artrite idiopática juvenil tinham escores-z de estatura para idade < -2 (baixa estatura). Meninas com artrite idiopática juvenil poliarticular e doses cumulativas de glicocorticoides foram significativamente mais propensas a apresentar baixa estatura. A porcentagem de meninas pré-púberes no grupo artrite idiopática juvenil foi significativamente maior do que a observada no grupo controle (p = 0,012). A idade da menarca, a estatura adulta e a diferença entre a estatura real e a esperada não diferiram entre os grupos. Conclusão Esses achados sugerem que, mesmo após seis meses da suspensão do tratamento com glicocorticoides, as crianças com os subtipos poliarticular/sistêmico de AIJ ainda são suscetíveis a baixa estatura e atraso na puberdade.

Association of body fat ratio with precocious puberty in girls / 中国当代儿科杂志

OBJECTIVE@#To study the association of body fat ratio with precocious puberty in girls. Previous studies have shown that body mass index (BMI) is associated with the girls' age of puberty but have not revealed the association of body fat ratio with age of puberty.@*METHODS@#Based on the consensus on the diagnosis and treatment of central precocious puberty (CPP), 128 children with precocious puberty who were admitted to the hospital from July to August, 2017, were divided into a CPP group with 87 children and a peripheral precocious puberty (PPP) group with 41 children. A total of 51 girls without any puberty development signs were enrolled as the control group. Dual-energy X-ray absorptiometry was used to measure the body fat ratios of upper limbs, legs, trunk, android area, gynoid area, and the whole body. The association between body fat ratios and precocious puberty was analyzed with reference to age, BMI, BMI-Z score, bone age, ovarian volume, and hormone levels.@*RESULTS@#Compared with the control group, the CPP and PPP groups had significantly higher body fat ratios of upper limbs, legs, trunk, android area, gynoid area, and the whole body, legs/whole body fat ratio, and (upper limbs+legs)/trunk fat ratio (P0.05). For the girls with precocious puberty, the high body fat ratio group had significantly higher luteinizing hormone (LH) base value, luteinizing hormone releasing hormone (LHRH)-stimulated LH peak value, and LH/follicle-stimulating hormone peak value than the low body fat ratio group (P<0.05). Compared with the control group, both the high body fat ratio and low body fat ratio groups had a significantly higher LH base value (P<0.05).@*CONCLUSIONS@#The increase in body fat may be a factor inducing precocious puberty in girls, but further studies are needed to determine the mechanism.

The association between sleep duration, bedtimes, and early pubertal timing among Chinese adolescents: a cross-sectional study

BACKGROUND AND OBJECTIVE@#Early pubertal timing is associated with sleep among Western adolescents, but little is known about this association in Chinese adolescents, especially with regard to the association between bedtimes and early pubertal timing. This paper aimed to identify the association between sleep duration, bedtimes, and early pubertal timing in Chinese adolescents.@*METHODS@#An anonymous cross-sectional survey was conducted among primary and junior middle students (grades 3 to 9) from QiJiang District, ChongQing, China. Participants were recruited by applying stratified cluster sampling. Pubertal timing, sleep duration, and bedtimes were assessed using the Pubertal Development Scale and a self-designed sleep questionnaire. We utilized multivariable logistic linear regression (MLLR) to test the association between sleep duration, bedtimes, and pubertal timing.@*RESULTS@#A total of 5461 adolescents were evaluated, with mean age and BMI values of 11.41 ± 2.05 and 18.03 ± 3.03, respectively, of whom 1257 (23.02%) were in early pubertal timing. In MLLR controlling for age, BMI, family economic status, and other covariates, sufficient sleep (b = - 0.214, P = 0.032, OR = 0.808, 95% CI 0.664-0.982) was negatively related to early pubertal timing, and later bedtime (b = 0.195, P < 0.001, OR = 1.215, 95% CI 1.104-1.338) was positively associated with early pubertal timing.@*CONCLUSION@#Students with early pubertal timing had less sleep duration and later bedtimes, which may be the result of increased stress caused by physical and psychological changes. Therefore, more attention should be paid to pubertal health education for adolescents during puberty. Further longitudinal studies are needed to confirm the causality between sleep and early pubertal timing in Chinese adolescents.

Fenótipos corporais na adolescência: é necessário ajustar o índice de massa corporal de acordo com os estágios de maturação sexual? / Body phenotypes in adolescence: is it necessary to adjust body mass index according to sexual maturation stages? / Fenotipos corporales en la adolescencia: ¿es necesario ajustar el índece de masa corporal de acuerdo a las fases de madurez sexual?

Resumo: O objetivo deste trabalho é analisar o efeito da maturação sexual sobre os fenótipos corporais gerados por análise multivariada do estado nutricional de adolescentes. Este é um estudo transversal e a amostra foi composta por 833 adolescentes escolares de 10 a 15 anos, selecionados por amostragem complexa em Piracicaba, São Paulo, Brasil. Os fenótipos corporais foram definidos por análise de componentes principais (ACP), a partir da idade, dados antropométricos (massa corporal, altura, dobras cutâneas e circunferência da cintura), composição corporal (ângulo de fase medido por impedância bioelétrica) e bioquímicos (triglicerídeos, glicose, razão colesterol total/LDL, hemoglobina). Os fenótipos corporais definidos foram: F1adiposidade caracterizada pela associação positiva com as variáveis dobras cutâneas, massa corporal e circunferência da cintura; F2crescimento caracterizado pela associação positiva entre altura e idade; F3bioquímico caracterizado pela associação positiva com razão colesterol/LDL, triglicerídeos e glicose; e F4metabólico caracterizado pela associação positiva com ângulo de fase, hemoglobina e negativa com glicose. Posteriormente, os fenótipos corporais foram considerados desfechos na análise dos efeitos mistos, incorporando o sexo no primeiro nível e as variáveis maturação sexual, idade, sexo e escore socioeconômico no segundo nível. Esta análise permitiu dimensionar o efeito da maturação sexual nos fenótipos corporais. Nossos resultados indicam que a maturação sexual apresentou variabilidade de explicação relevante somente sobre o fenótipo corporal que representa crescimento linear (altura e idade). Dessa forma, não é necessário ajustar as medidas antropométricas pela maturação sexual.

Abstract: This study aimed to analyze the effect of sexual maturation on body phenotypes, based on multivariate analysis of adolescents' nutritional status. This was a cross-sectional study with a sample of 833 adolescent schoolchildren 10 to 15 years of age, selected by complex sampling in Piracicaba, São Paulo State, Brazil. Body phenotypes were defined by principal components analysis (PCA), based on age, anthropometric data (body mass, height, skinfolds, and waist circumference), body composition (phase angle measured by bioelectrical impedance), and biochemical parameters (triglycerides, glucose, total cholesterol/LDL ratio, hemoglobin). Body phenotypes were classified as: P1adiposity characterized as positive association with skinfolds, body mass, and waist circumference; P2growth characterized as positive association between height and age; P3biochemical characterized as positive association with total cholesterol/LDL ratio, triglycerides, and glucose; and P4metabolic characterized as positive association with phase angle and hemoglobin and negative association with glucose. The phenotypes were later considered outcomes in the mixed effects analysis, incorporating sex at the first level and sexual maturation, age, sex, and socioeconomic score at the second level. This analysis allowed measuring the effect of sexual maturation on body phenotypes. Our results indicate that sexual maturation only a displayed relevant explanation of body phenotype that represents linear growth (height and age). Thus, it is not necessary to adjust anthropometric measures by sexual maturation.

Resumen: El objetivo de este trabajo es analizar el efecto de la madurez sexual sobre los fenotipos corporales generados por análisis multivariado del estado nutricional de adolescentes. Este es un estudio transversal, cuya la muestra estuvo compuesta por 833 adolescentes escolares de 10 a 15 años, seleccionados por muestra compleja en Piracicaba, São Paulo, Brasil. Los fenotipos corporales se definieron por análisis de componentes principales (ACP), a partir de la edad, datos antropométricos (masa corporal, altura, pliegues cutáneos y circunferencia de la cintura), composición corporal (ángulo de fase medido por impedancia bioeléctrica) y bioquímicos (triglicéridos, glucosa, razón colesterol total/LDL, hemoglobina). Los fenotipos corporales definidos fueron: F1adiposidad, caracterizada por la asociación positiva con las variables pliegues cutáneos, masa corporal y circunferencia de la cintura; F2crecimiento, caracterizado por la asociación positiva entre altura y edad; F3bioquímico, caracterizado por la asociación positiva con razón colesterol/LDL, triglicéridos y glucosa; y F4metabólico, caracterizado por la asociación positiva con ángulo de fase, hemoglobina y negativa con glucosa. Posteriormente, los fenotipos corporales fueron considerados resultados en el análisis de los efectos mixtos, incorporando el sexo en el primer nivel y las variables de madurez sexual, edad, sexo y marcador socioeconómico en el segundo nivel. Este análisis permitió dimensionar el efecto de la madurez sexual en los fenotipos corporales. Nuestros resultados indican que la madurez sexual presentó variabilidad de explicación relevante solamente sobre el fenotipo corporal que representa crecimiento lineal (altura y edad). De esta forma, no es necesario ajustar las medidas antropométricas por la madurez sexual.