Gender and age differences in the sleep habits : a cross-sectional study in adolescents

Objectives: Analyze gender and age differences in sleep habits in a sample of adolescents. Design: A cross-sectional study. Setting: Public schools of Viseu, Portugal. Participants: Sample consisted of 7534 students, aged 11-20 years (mean age: 14.96 ± 1.81 years; 53.6% girls). Measurements: Data was collected using a self-administered questionnaire, answered in class and consists of questions to assess insomnia (DSM-IV criteria), sleep patterns, socio-demographic and daily habit variables. Results: Mean sleep duration in this sample was 8.02 ± 1.13 h. Age interfered with sleep duration that decreased with the increasing of age, from 8.45 ± 1.14 h among 11/12 years old to 7.37 ± 1.04 h for ages ≥ 17 years old. Insomnia and symptoms of insomnia were associated with gender and with increasing of age. Nearly 80% of students reported daytime tiredness, 66.7% sleepiness during the day; 56.1% during classes and 47.6% reported waking up with headaches, all variables more prevalent among girls and older adolescents. Conclusions: The sleep problems and variables related to sleep have become more frequent among girls and with increasing age. We recommend that the promotion of sleep hygiene and prevention of the consequences should be encouraged in adolescents and their families, especially among the female gender and older adolescents.

Knowledge about sources of dietary fibres and health effects using a validated scale: a cross-country study

Objectives Dietary fibre (DF) is one of the components of diet that strongly contributes to health improvements, particularly on the gastrointestinal system. Hence, this work intended to evaluate the relations between some sociodemographic variables such as age, gender, level of education, living environment or country on the levels of knowledge about dietary fibre (KADF), its sources and its effects on human health, using a validated scale. Study design The present study was a cross-sectional study. Methods A methodological study was conducted with 6010 participants, residing in 10 countries from different continents (Europe, America, Africa). The instrument was a questionnaire of self-response, aimed at collecting information on knowledge about food fibres. The instrument was used to validate a scale (KADF) which model was used in the present work to identify the best predictors of knowledge. The statistical tools used were as follows: basic descriptive statistics, decision trees, inferential analysis (t-test for independent samples with Levene test and one-way ANOVA with multiple comparisons post hoc tests). Results The results showed that the best predictor for the three types of knowledge evaluated (about DF, about its sources and about its effects on human health) was always the country, meaning that the social, cultural and/or political conditions greatly determine the level of knowledge. On the other hand, the tests also showed that statistically significant differences were encountered regarding the three types of knowledge for all sociodemographic variables evaluated: age, gender, level of education, living environment and country. Conclusions The results showed that to improve the level of knowledge the actions planned should not be delineated in general as to reach all sectors of the populations, and that in addressing different people, different methodologies must be designed so as to provide an effective health education.