Association between blood pressure, body mass index, eating habits, and physical activity in adolescents / Associação entre pressão arterial, índice de massa corporal, hábitos alimentares e atividade física em adolescentes

AIMS: This study sought to analyze blood pressure and its association with eating behavior, physical activity, and body mass index in high school students. METHODS: A cross-sectional study was performed with high school students from midwestern Brazil. Blood pressure was measured according to the guidelines outlined by the Brazilian Society of Cardiology. Nutritional status was assessed in accordance with the Brazilian Food and Nutrition Surveillance System (Sistema de Vigilância Alimentar Nutricional, SISVAN), according to the standard reference of the National Health and Nutritional Examination Survey (NHANES II), and the level of physical activity was assessed by the International Physical Activity Questionnaire-Short Form. The chi-square test and the Mann-Whitney U test were used for characterization of the population and comparisons between genders and normotensive and prehypertensive subjects. Bivariate and multivariate regression analyses were performed to verify the relationship between blood pressure, physical activity, and eating behavior. The significance level was set at p<0.05. RESULTS: Prehypertension was detected in 26% of the students and overweight frequency was higher than the national average (38% for girls and 20% for boys). Concerning eating behavior, students' nutritional habits were "very good" in 7%, "regular" in 68%, and "poor" in 24%. In bivariate analyses, systolic blood pressure and blood pressure percentile were positively associated with body mass index. In multivariate analyses, there were positive associations between eating behavior and body mass index with diastolic blood pressure: when body mass index was high and the eating behavior score was low (unhealthy eating habits), diastolic blood pressure was high. No relationship was observed between blood pressure and physical activity. CONCLUSIONS: The adolescents assessed in this study showed a high frequency of prehypertension. Body mass index was positively associated with high blood pressure, indicating that a high body mass index is a risk factor for the development of hypertension among adolescents. Therefore, early intervention to control body mass index may be a valuable strategy to prevent overweight, obesity, and hypertension.

OBJETIVOS: Este estudo procurou analisar a pressão arterial e suas associações com comportamento alimentar, atividade física e índice de massa corporal em estudantes do ensino médio. MÉTODOS: Um estudo transversal foi conduzido com estudantes do ensino médio do Centro-Oeste do Brasil. A pressão arterial foi mensurada de acordo com as diretrizes da Sociedade Brasileira de Cardiologia. O estado nutricional foi classificado de acordo com o Sistema de Vigilância Alimentar Nutricional (SISVAN), com base nos critérios de referência do National Health and Nutritional Examination Survey (NHANES II); e o nível de atividade física foi avaliado por meio do Questionário Internacional de Atividade Física, Forma Curta. O teste do Qui quadrado e o teste de Mann-Whitney foram usados para as comparações entre os gêneros e os sujeitos com pressão arterial normal e pré-hipertensão. As associações entre pressão arterial, atividade física e comportamento alimentar foram avaliadas pelos testes de regressão bivariada e multivariada. O nível de significância estabelecido foi de p<0,05. RESULTADOS: Foi detectada pré-hipertensão em 26% dos estudantes e a frequência de sobrepeso foi maior do que a média nacional, 38% em meninas e 20% em meninos. Em relação ao comportamento alimentar, foram encontrados 7% de estudantes com hábitos "muito bons", 68% "regulares" e 24% com hábitos nutricionais "ruins". Nas análises bivariadas, a pressão arterial sistólica e o percentil da pressão arterial associaram-se positivamente com índice de massa corporal. Nas análises multivariadas houve associação positiva entre comportamento alimentar e índice de massa corporal com pressão arterial diastólica: quando o índice de massa corporal era alto e o escore nutricional era baixo (hábitos alimentares não saudáveis), a pressão arterial diastólica era alta. Não foi observada relação entre pressão arterial e nível de atividade física. CONCLUSÕES: Os adolescentes incluídos no estudo apresentaram alta frequência de pré-hipertensão. O índice de massa corporal associouse positivamente com pressão arterial, de forma que o índice de massa corporal elevado pode ser considerado como fator de risco para o desenvolvimento de hipertensão arterial em adolescentes. Assim, a intervenção precoce para controlar o índice da massa corporal pode ser uma estratégia valiosa para prevenir o sobrepeso, a obesidade e a hipertensão arterial.

Moderate physical exercise attenuates the alterations of feeding behaviour induced by social stress in female rats.

Epidemiological studies have demonstrated that stress-related disorders, such as the increase on the caloric intake, are twice as common in women as in men, but surprisingly, very few studies have been tested this subject on female experimental animals. Additionally, it has been proposed that regular physical exercise can improve the deleterious effects of stress. Therefore, the present longitudinal study, performed in female rats, aimed to test the influence of chronic stress (ST) imposed by social isolation on the animals' caloric intake and to assess the effect of regular physical exercise of low intensity on this behaviour. In 4 groups of Wistars rats (control sedentary, n = 6; control exercised, n = 6; ST sedentary, n = 6; ST exercised, n = 6), body weight, food intake, abdominal fat weight, adrenal weight, corticosterone metabolites in faeces and plasma insulin levels were measured during the experimental protocol and/or at its end. The results showed that social isolation was not able to modify the amount of abdominal fat and the body weight; however, it promoted significant increases in the corticosterone metabolites and in the amount of caloric intake, which were attenuated in exercised rats. Additionally, exercised groups presented lower levels of fasting insulin than sedentary groups. Therefore, the present study demonstrated that regular physical exercise of low intensity attenuates the corticosterone metabolites and overeating behaviour triggered by social stress.