Evaluation of sleep-wake cycles among high school evening students who work and don’t work from São Paulo, Brazil

Author(s)

Liliane Reis Teixeira

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Saúde Pública (FSP/CIR)
• Defense date: 2002-08-21

Examining board members

Frida Marina Fischer; Maria Izabel Galvao Gomes Pereira; Lúcia Rotenberg

• Advisor: Frida Marina Fischer

Abstract

Changes of the sleep-wake cycle are associated to several factors, such as, puberty, school hours, duration and type of activities during free time, working hours. The objective of this study was to evaluate patterns of sleep-wake cycles among high school students who work and don’t work. Twenty-seven high school students, ages 14-18 years old participated in the study. They were studying in a public school of São Paulo, Brazil. Their Monday-Friday study hours were 19:00 to 22:30h. They answered a comprehensive questionnaire about working and living conditions, and reported health symptoms and diseases. Also, activity- rest measurements were continuously recorded with Actigraph (Ambulatory Monitoring, USA). Activities and sleep dairies during 15 consecutive days were also reported. Main variables were tested using one factor ANOVA and t-Student tests were performed to compare sleep duration during Monday-Friday and weekends. It was used Tukey HSD test for multiple comparisons among the variables. Results of sleep showed working students went to sleep earlier during weekends [F(1,23)= 6.1; p= .02] and woke up earlier during working days than non-working students [F(1,23)=17,3; p= .00].The duration of night sleep is shorter among working students [F(1,23)= 16,7; p= .00], and males [F(1,23)=10,8; p= .00] than non-working students. The male working students showed a shorter nap duration during the working week [F(1,23)= 5,6; p= .03] compared to females and non-working students. Reported sleep complaints were “difficulties waking up in the morning" [F(1,23)= 6,2; p= .02]. Conclusions: work caused negative consequences to sleep among adolescents, with possible build up of a chronic sleep debt. This can affect the quality of life, and schooling development of working students. (AU)