Explaining sleep duration in adolescents: The impact of socio-demographic and lifestyle factors and working status

Previous studies found students who both work and attend school undergo a partial sleep deprivation that accumulates across the week. The aim of the present study was to obtain information using a questionnaire on a number of variables (e.g., socio-demographics, lifestyle, work timing, and sleep-wake habits) considered to impact on sleep duration of working (n = 51) and non-working (n = 41) high-school students aged 14-21 yrs old attending evening classes (19:00-22:30h) at a public school in the city of Sao Paulo, Brazil. Data were collected for working days and days off. Multiple linear regression analyses were performed to assess the factors associated with sleep duration on weekdays and weekends. Work, sex, age, smoking, consumption of alcohol and caffeine, and physical activity were considered control variables. Significant predictors of sleep duration were: work (p < 0.01), daily work duration (8-10h/day; p < 0.01), sex (p = 0.04), age 18-21 yrs (0.01), smoking (p = 0.02) and drinking habits (p = 0.03), irregular physical exercise (p < 0.01), ease of falling asleep (p = 0.04), and the sleep-wake cycle variables of napping (p < 0.01), nocturnal awakenings (p < 0.01), and mid-sleep regularity (p < 0.01). The results confirm the hypotheses that young students who work and attend school showed a reduction in night-time sleep duration. Sleep deprivation across the week, particularly in students working 8-10h/day, is manifested through a sleep rebound (i.e., extended sleep duration) on Saturdays. However, the different roles played by socio-demographic and lifestyle variables have proven to be factors that intervene with nocturnal sleep duration. The variables related to the sleep-wake cyclenaps and night awakeningsproved to be associated with a slight reduction in night-time sleep, while regularity in sleep and wake-up schedules was shown to be associated with more extended sleep duration, with a distinct expression along the week and the weekend. Having to attend school and work, coupled with other socio-demographic and lifestyle factors, creates an unfavorable scenario for satisfactory sleep duration.

Prevalence and severity of dental caries in schoolchildren of Porto, Portugal

Objectives: To measure the prevalence and severity of dental caries in adolescents of the city of Porto, Portugal, and to assess socioeconomic and behavioural covariates of dental caries experience. Methods: A sample of 700 thirteen-year-old schoolchildren was examined. Results from the dental examination were linked to anthropometric information and to data supplied by two structured questionnaires assessing nutritional factors, socio-demographic characteristics and behaviour related to health promotion. Dental caries was measured using the DMFT index, and two dichotomous outcomes, one assessing the prevalence of dental caries (DMFT>0); the other assessing the prevalence of a high level of dental caries (DMFT=4). Results: Consuming soft drinks derived from cola (irrespective of sugared or diet) two or more times per week, attending a public school, being female and having parents with low educational attainment were identified as risk factors both for having dental caries and for having a high level of dental caries. Conclusion: Caries levels were positively associated with frequency of intake of sweetened foods and drinks.

Untreated dental caries in children with cerebral palsy in the Brazilian context

Objectives. To assess the prevalence of untreated dental caries in children with cerebral palsy and to assess socio-demographic, behavioural, and clinical covariates. Design. Cross-sectional assessment of 200 children and adolescents with cerebral palsy (2-17 years old) enrolled in a specialized healthcare unit in Sao Paulo, Brazil. The dental examination followed the World Health Organization`s guidelines for oral health surveys; familial caretakers informed on socio-economic status and behaviour; the patient`s medical record informed their clinical status. Results. The proportion of children that presented at least one tooth affected by untreated caries was 49.5%. Poor socio-economic standings and a higher frequency of sugar consumption associated with a worse profile of dental health; different types of cerebral palsy (spastic, tetraparesis) did not. The prevalence of untreated caries was higher than reference values assessed for the overall population of the same age range. Conclusions. The high burden of untreated dental caries on cerebral palsy patients reinforces the importance of the dentist in the interdisciplinary healthcare team attending these children. Factors associated with this outcome are the same for the general population; these findings underscore the necessity of implementing effective caries prevention in this population of cerebral palsy children.

The influence of maternal factors on the concentration of vitamin A in mature breast milk

Background & aims: This study evaluated the relationship between vitamin A concentration in maternal milk and the characteristics of the donors of a Brazilian human milk bank. Material and methods: A total of 136 donors were selected in 2003-2004 for micronutrient determinations in breast milk and blood, anthropometric measurements and investigation of obstetric, socioeconomic-demographic factors, and life style. Maternal serum/milk samples were obtained for vitamin A, iron, copper, and zinc determinations. Vitamin A concentrations in breast milk and blood were assessed by high-performance liquid chromatography. Copper, zinc and iron concentrations in breast milk, and copper and zinc concentrations in blood were detected by atomic emission spectrophotometry. Serum ceruloplasmin and serum iron were determined, respectively, by nephelometry and colorimetry. A linear regression model assessed the associations between milk concentrations of vitamin A and maternal factors. Results: Vitamin A in milk presented positive associations with iron in milk (p < 0.001), serum retinol (p = 0.03), maternal work (p = 0.02), maternal age (p = 0.02). and oral contraceptive use (p = 0.01), and a negative association with % body fat (p = 0.01) (R(2) = 0.47). Conclusion: These results suggest that some nutritional, obstetric, and socioeconomic-demographic factors may have an effect on mature breast milk concentrations of vitamin A in apparently healthy Brazilian mothers. (C) 2009 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.