Tempo de sono e variação do IMC em escolares: análise conjunta de seis ensaios randomizados de base escolar / Sleep time and BMI variation in schoolchildren: a pooled analysis of five school - based randomized trials

Crianças e adolescentes têm apresentado sono insuficiente levando ao risco de desenvolvimento de doenças. Estudos transversais mostram que poucas horas de sono estão associadas com obesidade, já em estudos longitudinais esses resultados são inconclusivos. O objetivo desse estudo é analisar a relação entre tempo de sono inadequado (curto e longo) e variação do IMC em escolares. Foram utilizados dados de 5 ensaios randomizados de base escolar para prevenção de obesidade, que ocorreram de 2005 a 2019, com duração de um ano letivo, totalizando 5369 escolares. O tempo de sono foi avaliado na linha de base e categorizado em sono curto, adequado e longo de acordo com os pontos de corte recomendado pela American Academy of Sleep Medicine (2016). Empregou-se análise longitudinal com efeitos mistos, considerando o efeito de cluster das escolas, para verificar a taxa de variação do IMC ao longo do tempo segundo o tempo de sono. Foram realizadas análises brutas e ajustadas por possíveis fatores de confundimento (sexo, tempo de tela, e raça/cor), utilizando o software SAS. A idade em cada estudo foi utilizada como variável indicadora do tempo, e os modelos foram adicionalmente ajustados pelo ano de cada pesquisa, com o objetivo de corrigir o modelo para o aumento do IMC com a idade. Observou-se que 17,2% dos estudantes apresentaram sobrepeso e 11,6% obesidade; 31% dos estudantes apresentaram sono curto e 8,9% apresentaram sono longo. As médias de idade, peso, estatura e IMC foram maiores entre aqueles que apresentaram sono longo tanto na linha de base (12,8; 47,1; 154,8 e 19,4, respectivamente) como no seguimento (13,2; 49,4; 156,8 e 19,8, respectivamente). Contudo, a variação do IMC ao longo do tempo não foi alterada de acordo com o de tempo de sono (p-valor =0,93). O presente estudo, envolvendo análise agrupada com um ano de duração, não identificou efeito na associação entre tempo de sono e variação do IMC. Os estudantes com tempo de sono longo apresentavam maior IMC na linha de base e assim se mantiveram ao longo do período de observação. (AU)

Children and adolescents have shown insufficient sleep leading to the risk of developing diseases. Cross-sectional studies show that few hours of sleep are associated with obesity, whereas in longitudinal studies, these results are inconclusive. The aim of this study is to analyze the relationship between inadequate sleep time (short and long) and BMI variation in schoolchildren. Data from 5 school-based randomized trials for obesity prevention, which took place from 2005 to 2019, lasted one school year, totaling 5369 schoolchildren, were used. Sleep time was assessed at baseline and categorized into short, adequate, and long sleep according to the cutoff points recommended by the American Academy of Sleep Medicine (2016). Longitudinal analysis with mixed effects was used, considering the cluster effect of schools, to verify the BMI variation rate over time according to sleep categories. Crude and adjusted analyses for possible confounding factors (gender, screen time, and race/color), were performed using the SAS software. Age in each study was used as the time indicator variable, and the models were additionally adjusted for the year of each study, with the objective of correcting the model for the increase in BMI with age. It was observed that 17.2% of students were overweight and 11.6% were obese. The frequency of adequate sleep was 60%, 31% of the students had a short sleep and 8.9% had long sleep. The mean age, weight, height and BMI were higher among those who had long sleep both at baseline (12.8; 47.1; 154.8 and 19.4, respectively) and at follow-up (13.2; 49.4; 156.8 and 19.8, respectively). However, the variation in BMI over time was not altered according to sleep time (p-value =0.93). The present study, involving longitudinal pooled analysis, did not identify an effect on the association between sleep time and BMI variation. Students with long sleep times had higher BMI at baseline and remained so throughout the observation. (AU)

Processed and ultra-processed foods consumption in adults and its relationship with quality of life and quality of sleep / Consumo de alimentos processados e ultraprocessados em adultos e sua relação com qualidade de vida e qualidade do sono

ABSTRACT Objective: To evaluate the consumption of processed and ultra-processed foods in Paraguayan adults and its relationship with quality of life and sleep quality. Methods: A cross-sectional descriptive observational study was carried out on Paraguayan adults in May 2022. An online survey was applied in which sociodemographic data, frequency of food consumption using the NOVA classification and Pan American Health Organization criteria, quality of life evaluated by the European Quality of Life-5 Dimensions and report of hours of sleep were collected. Results: A total of 273 Paraguayan adults were included in the study, of which 71.1% were female, 51.6% lived in the capital, 53.1% were single, 66% had a university educational level and the average age was 36.48±13.2. Regarding the consumption of processed and ultra-processed foods, the critical nutrients most consumed daily were free sugars by 34.0%, and fats by 23.4% of the population. The global quality of life index was low (0,58±0,05) and 69.0% reported insufficient hours of sleep. Statistically significant relationships were found between the consumption of processed and ultra-processed foods with quality of life and quality of sleep (p<0.05 for both). Conclusion: The most consumed critical nutrients in the Paraguayan adult population are free sugars and fats, finding a significant relationship between the consumption of processed and ultra-processed foods with quality of life and quality of sleep.

RESUMO Objetivo: Avaliar o consumo de alimentos processados e ultraprocessados em adultos paraguaios e sua relação com a qualidade de vida e qualidade do sono. Métodos: Foi realizado um estudo observacional descritivo transversal em adultos paraguaios em maio de 2022. Foi aplicado um questionário online onde foram questionados datos sociodemográficos, frequência de consumo alimentar pela classificação NOVA e critérios da Organização Pan-Americana da Saúde, qualidade de vida avaliada pelo Qualidade de Vida Europeia-5 Dimensões - foram coletados e relato de horas de sono. Resultados: Foram incluídas no estudo 273 paraguaios, das quais 71,1% eram do sexo feminino, 51,6% residiam na capital, 53,1% eram solteiras, 66,0% tinham nível universitário e a média de idade foi de 36,48±13,2 anos. Em relação ao consumo de alimentos processados e ultraprocessados, os nutrientes críticos mais consumidos diariamente foram os açúcares livres por 34.0% e as gorduras por 23,4% da população. O índice global de qualidade de vida foi baixo (0,58±0,05) e 69.0% relataram horas insuficientes de sono. Foram encontradas relações estatisticamente significativas entre o consumo de alimentos processados e ultraprocessados com qualidade de vida e qualidade do sono (p<0,05 para ambos). Conclusão: Os nutrientes críticos mais consumidos na população adulta paraguaia são os açúcares e gorduras livres, encontrando uma relação significativa entre o consumo de alimentos processados e ultraprocessados com a qualidade de vida e qualidade do sono.

Ansiedad durante pruebas de evaluación académica: influencia de la cantidad de sueño y la agresividad / Influence of sleep quantity and aggressiveness on anxiety during academics evaluation tests

The situation of academic evaluation has often been studied in relation to emotional alterations such as anxiety, stress or even fear. Possibly, aggressiveness may be another variable present in these situations. Aggressiveness seems to be present in different teaching activities as well as in all levels of the educational context, showing even more clearly in students with academic difficulties and especially when exposed to stressful situations. Various classical investigations have indicated for some time now that physical and verbal aggressiveness is more frequent in men than in women, and also more intense. The execution of academic tests is perceived as an aversive situation and often even as a threat, which may explain why they would be the cause of anxiety or stress. In fact, an intense emotional alteration could be present in nearly 25% of the students during the examination procedure; furthermore, exams are the most frequent evaluation method used in all educational levels. According to some studies, women seem to show higher levels of resources for coping with stressful situations, which would also be applied to circumstances of academic evaluation. Nevertheless, again in relation to gender differences, higher levels of anxiety have been found in women in comparison to men among university students before exams are carried out. In this situation the presence of aggressiveness does not seem to be clear. Although in the psychological environment there is no doubt of the negative effect which sleep deprivation has on different types of performance, we have observed with some frequency that university students tend to reduce sleep time days before an exam. The studies centred in the population of university students' quality of sleep have found that it quite often drops during this period. Thus, for example, in normal circumstances (not during exam periods), poor sleep quality can be found in approximately 30% of the university students. With this, we may suppose that the quality and the quantity could be even worse in exam periods. The quality of sleep has been studied frequently and also in relation to difficulties and psychological alterations. In the case of test anxiety, the correlation with the reduction of the quantity of sleep the previous night seems to be positive. Although multiple investigations have centred on the disrupting role that anxiety plays on the performance of exams, not many have focused on the relation between test-anxiety and aggressiveness in that situation, and even less so in circumstances of reduction of sleep hours. In the present work, we intend to determine first the possible presence of aggressiveness during the execution of exams in a sample of university students. At the same time, it was of our interest to establish a possible relation between sleep hours and the level of aggressiveness in that situation, keeping in mind that many students reduce sleep hours during this time, and specially the night before an exam. A second objective is to determine if different levels of aggressiveness may be related to different levels of test-anxiety. Thirdly, we try to seek differences between men and women's levels of aggressiveness while test circumstances, differences in aggressiveness in function of different age levels, as well as in function of different amount of time dedicated to sleep. In this study, 143 students aged 19-48 participated. The average age was 21.67, with a 3.79 standard deviation. Forty-two of the participants were men, 98 women and three of them did not consign their gender. All of them participated in the study just before beginning the execution of a final test in diverse subjects when they were already seated in the classroom. Aggressiveness was assessed with the reduced Spanish version of the Aggression Questionnaire (AQ). For the anxiety assessment, the Spanish version of the Spiel berger State-Trait Anxiety Inventory (STAI) was used, applying only the state scale. Additionally, participants were asked to note the hours of sleep they had had the previous night. The collection of data was carried out during a final exam, which assigned the final qualification in that subject. Several studies have shown the poor sleep quality in university students, being this significant characteristic a variable with possible and important implications in their quality of life, health, or even in their performance. Our data show that the average number of hours of sleep on the previous night to an exam was 6.43 (S.D. = 1.55), which indicates that the tendency to reduce the hours of sleep in this situation is a frequent habit among the university students being analyzed. Our descriptive results indicated that the levels of aggressiveness are not too high, although a certain degree does exist before the evaluation tests. The correlation analysis carried out indicates that having less hours of sleep the previous night is not associated with a higher level of aggressiveness [r = -.066 (p = .437)]. Nevertheless, when the sample was divided into two groups in function of the aggressiveness level, we found significative differences in the hours of sleep the previous night. The amount of sleep was higher in subjects with less aggressiveness. This result agreed with other studies that have found a relation between sleep deprivation and emotional alterations, specifically anxiety, or other psychological alterations. According to our data, the quantity of sleep had the previous night is related to the latter aggressiveness, and possibly with other aspects of this situation, like sensation of threat or anger. On the other hand, our data has shown significant differences in test-anxiety when we compared subjects with low and high levels of aggressiveness. The result indicates that subjects with high levels of aggressiveness showed higher levels of test-anxiety. This result agrees with those studies that have found an association between some varieties of emotional alterations, for example, social anxiety and aggressiveness and even one acceptable mediator role of social anxiety on social aggression. It has surprised us not to find significant differences between men and women's levels of aggressiveness, keeping in mind that this result goes against most studies that have verified these types of differences. Perhaps this result shows that in a specific threatening and aversive situation, such as an exam, women are able to show levels of latent aggressiveness as high those of as men. Furthermore, in the same way, this situation could create higher levels of aggressiveness in women students than many other daily situations could. Nevertheless, this conclusion is no more than a preliminary one and needs to be further investigated in the future. No significant differences were found between younger and older students' levels of aggressiveness. Although this result matches those obtained by other authors, in our case the reason for this might be the reduced number of age groups within the subjects. We interpret our results in the sense that sleeping less hours before an exam would perhaps be able to imply a worse performance in the test, even the possible presence of emotional alterations such as stress or anxiety, but would not imply significant differences in aggressiveness. The situation of examination in a university context, in function of our results, seems to be a quite specific context. Our study shows different results in contrast with the data on the effects sleep deprivation has on the psychological operation, as well as the patterns of latent aggressiveness found in other populations. The results of this line of investigation have practical implications on the teaching-learning processes, specifically in relation to evaluation as a fundamental element of them, as well as of the role that some psychological variables would perform in these procedures.

La agresividad parece estar presente en diversas actividades docentes así como en todos los grados y niveles del contexto educativo. Igualmente, diversas investigaciones clásicas han señalado desde hace tiempo la agresividad física y verbal como más intensa y frecuente en hombres que en mujeres. Por otra parte, con cierta frecuencia observamos que los estudiantes universitarios suelen reducir el tiempo que dedican al sueño en fechas previas a un examen. Los estudios centrados en el sueño de la población de estudiantes universitarios han encontrado con cierta frecuencia una relativa baja calidad del mismo. La realización de pruebas académicas suele ser percibida como una situación aversiva y frecuentemente incluso como amenazante, por lo que podría ser generadora de alteraciones emocionales como por ejemplo ansiedad o estrés. En el caso de la ansiedad a los exámenes, la correlación con la reducción en la cantidad de sueño la noche anterior parece ser positiva. En el presente trabajo se pretende determinar, en primer lugar, la posible presencia de agresividad durante la realización de exámenes en una muestra de estudiantes universitarios. Paralelamente es de interés establecer una posible relación entre horas de sueño la noche anterior y agresividad. Un segundo objetivo se centra en determinar si diferentes niveles de agresividad pueden relacionarse con ansiedad a los exámenes. En tercer lugar intentamos determinar si variables como el género, la edad, la ansiedad y la duración del sueño, pueden predecir diferencias en agresividad en nuestra muestra. Participaron 143 estudiantes con edades comprendidas entre 19-48 años. La media de edad fue de 21.67 años con una desviación estandar de 3.79. Cuarenta y dos de los participantes eran hombres, 98 mujeres, y tres de ellos no indicaron su género. La agresividad se evaluó con la versión española reducida del Aggression Questionnaire (AQ). Para la valoración de la ansiedad se utilizó la versión española del cuestionario de Ansiedad Estado-Rasgo de Spielberger (STAI), aplicándose únicamente la escala de evaluación de la ansiedad-estado. Adicionalmente se les pidió a los participantes que anotaran las horas de sueño que habían dormido la noche anterior al examen. Los datos se obtuvieron durante un examen final, donde estaba en juego la calificación definitiva de esa asignatura. Los datos muestran la tendencia a reducir las horas de sueño en los estudiantes universitarios estudiados, encontrándose un cierto grado de agresividad latente ante la realización de pruebas de evaluación. El análisis de correlación llevado a cabo indica que a mayores niveles de agresividad parece asociarse menor cantidad de sueño la noche anterior al examen, aunque esta relación no resultó significativa. Sin embargo, cuando dividimos a la muestra en grupos según el nivel de agresividad, sí se observan diferencias significativas en la cantidad de sueño la noche anterior al examen, siendo ésta menor en los sujetos más agresivos. Este resultado concuerda con aquellos otros estudios que sí han encontrado una relación entre pocas horas de sueño y alteraciones emocionales, específicamente ansiedad u otras alteraciones psicológicas. Se han encontrado diferencias significativas en ansiedad a los exámenes cuando comparábamos a sujetos con niveles bajos y altos de agresividad. La prueba de diferencia de medias confirma que los estudiantes más agresivos manifiestan mayores niveles de ansiedad a los exámenes en comparación con los estudiantes menos agresivos. Ha resultado sorprendente no encontrar diferencias significativas entre hombres y mujeres en los niveles de agresividad, teniendo en cuenta que este resultado va en contra de la mayor parte de estudios revisados. Quizá este resultado pueda deberse a que en una situación de amenaza tan específica como es un examen, las mujeres podrían mostrar niveles de agresividad latente tan elevados como los hombres. Este punto merece mayor investigación y atención futura. La asociación entre agresividad y baja duración del sueño se corresponde con un escenario bastante específico que se acerca en cierto sentido a los datos encontrados en otras poblaciones en cuanto a las repercusiones de la duración del sueño sobre el funcionamiento psicológico, así como en cuanto a los patrones de agresividad latente.