Sleep Hours: Risk behavior in adolescents from different countries

Sleep Medicine, 2016

To investigate factors associated with sleep duration in adolescence. Methods: Data are from the 1993 Pelotas Birth Cohort Study of 5249 live births. Of these individuals, 4563 were located for follow-up at 18 years of age, and 4106 agreed to be interviewed (follow-up rate 81.3%). Sleep duration was continuously assessed by survey as hours per weekday. Additional covariates were collected during the perinatal period and at the 11-and 18-year follow-ups. Linear regression models were used to estimate associations between sleep duration and its hypothesized influences. All analyses were sex-stratified. Results: The average sleep duration among participants was 8.4 hours (standard deviation 1.9). Longer sleep duration at 18 years of age was associated with the following perinatal factors: low maternal schooling, low family income, maternal black skin color, and low birth weight; and with the following factors measured at 18 years of age: being out of school, low achieved schooling, low family income, absence of depressive symptoms, and high screen time. Conclusion: Social and demographic variables may play an important role in determining adolescents' sleep duration, but the nature of these relationships in Brazil may differ from those observed in higherincome contexts.

International journal of adolescent medicine and health, 2016

Introduction: Adolescence is the period of transition between childhood and adult life, characterized by changes in physical, emotional, sexual and social development. Although during this phase most individuals are healthy, it is known that health status is related to behaviors and habits such as a healthy diet, the regular practice of physical activity and good sleep quality, which contribute to optimum physical and cognitive performance Objective: To determine some sleep characteristics of adolescents living in the city of Ribeirão Preto (SP). Methods: This was a cross-sectional descriptive study conducted at 14 schools in the city of Ribeirão Preto (SP) including adolescents aged 10 to 19 years who answered a questionnaire about sleep habits. The chi-square test was used to determine differences between genders with the aid of the EPI-INFO 7 software, with the level of significance set at p<0.05. Results: A total of 535 adolescents (65% girls) were included in the study. Of these, 47.7% studied during the morning period and 10.3% had a job and studied in the evening period. Regarding sleep duration, 242 (45%) slept less than 9 hours per night during week days and 256 (48%) during the weekends (Saturday and Sunday), Of the total number of adolescents studied, 75.5% reported that they went to bed when they felt sleepy, 90% reported delay in falling asleep, 84.3% used some type of electronic equipment before going to sleep, and 44% reported that they woke up during the night. In the morning, 70.3% needed to be awakened, and 44.7% reported a delay in waking up. During the daytime, 70% felt somnolent and 34% reported that they slept during the day. Girls reported that they felt more daytime sleepiness (71.3%) and slept more during the day (62.1%) than boys (28.7% and 37.9%, respectively), with the difference being statistically significant (p < 0.05). Conclusions: Almost half the adolescents investigated sleep less than the minimum time considered ideal. Furthermore, the most of adolescents went to the bed when they felt sleepy, used electronic devices before to sleep, had difficulties to fall asleep, need to be awake in the morning and felt sleepy during the day. A substantial proportion of adolescents studied awoke at night and slept during the day. Compared to boys, girls felt sleepy and slept during the day significantly.

MOJ Public Health, 2015

Objectives: To analyse the diverse mutual influences of sleep duration and sleep deprivation upon the sleep stealers and adolescent risk behaviours. Methods: The survey is a component of the Health Behaviour in School-Aged Children study, on 3476 students attending the 8th grade and the 10th grade; the mean age was 14.9 years. The questionnaire evaluated socio-demographics, sleep, sleep deprivation, sleep stealers and risk behaviours. Pearson correlations and chi-square tests were used to evaluate the behavioural differences between sleep deprived and non-sleep deprived students. Results: Sleep deprivation was present in 18.9% of the adolescents. Several behaviours had higher prevalence in sleep deprived adolescents, namely: excessive use of mobile phone, of computer use during week days and of internet facilities; substance use (tobacco, alcohol and drugs); violence (namely fights and carrying weapons to school); sexual relations and sedentary behaviour. No differences were found for TV viewing. Conclusion: Sleep stealers use and risk behaviors are increased by sleep deprivation; their correlations are complex in spite of similar association patterns. The prevalence of both sleep stealers and risk behaviours varies markedly across countries and therefore cultural differences, comparing youngsters of several continents and countries, are discussed.

Sleep Medicine, 2016

Objective: In this epidemiological study, we evaluate the impact of school-time in sleep parameters in children and adolescents. Methods: This cross-sectional study involved 639 elementary and high-school students (mean age 13.03 years [range: 8-18]; 58.5% female) from the south of Brazil. Participants answered the Morningness-Eveningness Questionnaire (MEQ), and asked as to their sleeping habits on weekdays and the weekend. Sleep deficit was defined as the difference between sleep duration on weekdays and weekend. Results: The morning school-time students presented the significantly highest age, bedtime and wake up differences, sleep deficit and social jet lag. The sleep deficit presented by girls was greater than that observed in boys of the same age. The difference between weekdays and weekend waking times was also significantly greater in girls than boys aged 13 to 18 years. Sleep deficit was significant positively correlated with age and difference in wake up times; and significant negatively correlated with MEQ scores, social jet lag, difference between weekdays and weekend bedtimes, midpoint of sleep on free days and midpoint of sleep on free days corrected for sleep deficit. A step-by-step multivariate logistic regression identified social jetlag, the difference between weekdays and weekend waking times, and the midpoint of sleep on free days as significant predictors of sleep deficit (Adjusted R 2 = 0.95; F = 1606.87; p < 0.001). Conclusion: Our results showed that school-time influences the sleep parameters. The association of school schedules and physiological factors influence the sleep/wake cycle.

Arquivos de Neuro-Psiquiatria, 2005

Objective: This study investigated the sleep habits in Brazilian children according to age, gender and starting time to school. Method: We investigated 2,482 scholars aged 7 to 10 years. We compared sleep habits, gender, and starting time to school (morning and aftern o o n ) . R e s u l t s: Sixty-one per cent of the children presented sleep rituals before sleep. Milk drinking before sleep was more frequent among seven years old children. We found a progressive reduction with age in keeping the lights on. Girls used to leave an object to bed more than boys did. Children that studied in the morning presented reduced total sleep time, sleep earlier, and nap more frequently than children that studied in the afternoon. Conclusion. Starting time to school deeply influences sleep habits in Brazilian children from São Paulo City, in whom bed-time rituals are highly prevalent.

2014

Background: Sleep duration, either short or long, has been associated with diseases such as obesity, type-2 diabetes and cardiovascular diseases. Characterizing the prevalence and patterns of sleep duration at the population-level, especially in resource-constrained settings, will provide informative evidence on a potentially modifiable risk factor. The aim of this study was to explore the patterns of sleep duration in the Peruvian adult and adolescent population, together with its socio-demographic profile. Material and methods: A total of 12, 424 subjects, mean age 35.8 years (SD ±17.7), 50.6% males, were included in the analysis. This is a cross-sectional study, secondary analysis of the Use of Time National Survey conducted in 2010. We used weighted means and proportions to describe sleep duration according to socio-demographic variables (area and region; sex; age; education attainment; asset index; martial and job status). We used Poisson regressions, taking into account the multistage sampling design of the survey, to calculate crude and adjusted prevalence ratios (PR) and 95% confidence intervals (95% CI). Main outcomes were short-(<6 hours) and long-sleep duration (9 hours). ≥ Results: On average, Peruvians slept 7.7 hours (95% CI 7.4-8.0) on weekdays and 8.0 hours (95% CI 7.8-8.1) during weekends. The proportions of short-and long-sleep, during weekdays, were 4.3% (95% CI 2.9%-6.3%) and 22.4% (95% CI 14.9%-32.1%), respectively. Regarding urban and rural areas, a much higher proportion of shortsleep was observed in the former (92.0% vs. 8.0%); both for weekdays and weekends. On the multivariable analysis, compared to regular-sleepers (6 to <9 hours), short-sleepers ≥ were twice more likely to be older and to have higher educational status, and 50% more likely to be currently employed. Similarly, relative to regular-sleep, long-sleepers were more likely to have a lower socioeconomic status as per educational attainment. Conclusions: In this nationally representative sample, the sociodemographic profile of short-sleep contrasts the long-sleep. These scenarios in Peru, as depicted by sleeping duration, differ from patterns reported in other high-income settings and could serve as the basis to inform and to improve

International Journal of Adolescent Medicine and Health, 2016

Sleep is an important physiological condition that plays a role in the physical and emotional development of adolescents. The aim of the study is to determine some sleep characteristics of adolescents living in the city of Ribeirão Preto (SP).This is a cross-sectional descriptive study conducted at 14 schools in the city of Ribeirão Preto (SP) including adolescents aged 10–19 years using a questionnaire about sleep habits. The χA total of 535 adolescents (65% girls) were included in the study. Of these, 47.7% studied during the morning period and 10.3% had a job and studied in the evening period. Regarding sleep duration, 242 (45%) slept &lt;9 h per night during week days and 256 (48%) during the weekends (Saturday and Sunday). Of the total number of adolescents studied, 75.5% reported that they went to bed when they felt sleepy, 90% reported delay in falling asleep, 84.3% used some type of electronic equipment before going to sleep, and 44% reported that they woke up during the nig...

PeerJ, 2014

Background. Sleep duration, either short or long, has been associated with diseases such as obesity, type-2 diabetes and cardiovascular diseases. Characterizing the prevalence and patterns of sleep duration at the population-level, especially in resource-constrained settings, will provide informative evidence on a potentially modifiable risk factor. The aim of this study was to explore the patterns of sleep duration in the Peruvian adult and adolescent population, together with its sociodemographic profile. Material and Methods. A total of 12,424 subjects, mean age 35.8 years (SD ±17.7), 50.6% males, were included in the analysis. This is a cross-sectional study, secondary analysis of the Use of Time National Survey conducted in 2010. We used weighted means and proportions to describe sleep duration according to socio-demographic variables (area and region; sex; age; education attainment; asset index; martial and job status). We used Poisson regressions, taking into account the multistage sampling design of the survey, to calculate crude and adjusted prevalence ratios (PR) and 95% confidence intervals (95% CI). Main outcomes were short-(<6 h) and long-sleep duration (≥9 h). Results. On average, Peruvians slept 7.7 h (95% CI [7.4-8.0]) on weekdays and 8.0 h (95% CI [7.8-8.1]) during weekends. The proportions of short-and longsleep, during weekdays, were 4.3% (95% CI [2.9%-6.3%]) and 22.4% (95% CI [14.9%-32.1%]), respectively. Regarding urban and rural areas, a much higher proportion of short-sleep was observed in the former (92.0% vs. 8.0%); both for weekdays and weekends. On the multivariable analysis, compared to regular-sleepers (≥6 to <9 h), short-sleepers were twice more likely to be older and to have higher educational status, and 50% more likely to be currently employed. Similarly, relative to regular-sleep, long-sleepers were more likely to have a lower socioeconomic status as per educational attainment. Conclusions. In this nationally representative sample, the sociodemographic profile of short-sleep contrasts the long-sleep. These scenarios in Peru, as depicted by sleeping duration, differ from patterns reported in other high-income settings and could serve as the basis to inform and to improve sleep habits in the population. Moreover, it seems important to address the higher frequency of short-sleep duration found in urban versus rural settings. How to cite this article Carrillo-Larco et al. (2014), Peruvians' sleep duration: analysis of a population-based survey on adolescents and adults. PeerJ 2:e345; Miller MA. 2011. Sleep duration predicts cardiovascular outcomes: a systematic review and meta-analysis of prospective studies. European Heart Journal 32:1484-1492 DOI 10.1093/eurheartj/ehr007. Cappuccio FP, D'Elia L, Strazzullo P, Miller MA. 2010a. Quantity and quality of sleep and incidence of type 2 diabetes: a systematic review and meta-analysis. Diabetes Care 33:414-420 DOI 10.2337/dc09-1124. Cappuccio FP, D'Elia L, Strazzullo P, Miller MA. 2010b. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep 33:585-592. Chang JJ, Pien GW, Duntley SP, Macones GA. 2010. Sleep deprivation during pregnancy and maternal and fetal outcomes: is there a relationship? Sleep Medicine Reviews 14:107-114 Sun Y. 2013. Epidemiological evidence for the link between sleep duration and high blood pressure: a systematic review and meta-analysis. Hargreaves JR. 2012. Measuring socio-economic position for epidemiological studies in low-and middle-income countries: a methods of measurement in epidemiology paper.

Pediatrics International, 2008

Studies in Sociology of Science, 2014

Introduction: The pattern of sleep plays an important role in protecting the adolescents' health. The main objective of this research is to determine the relationship between sufficient sleep (≥ 8 hours of sleep per night on school days) and health-risk behaviours in Portuguese adolescents. Methods: 5,050 participants with an average age of 13.98 (DP ± 1.85), 52.3% of which were female. The instrument used was the Health Behaviour in School-aged Children 2010 (HBSC) questionnaire. The associations were studied by applying χ² tests and the multivariate logistic regression models. Results: A significant percentage of adolescents (39%) get less than 8 hours sleep on weekdays. Sufficient sleep (≥ 8 h) is associated with younger age: adolescents between the ages of 13 and 15 (OR=0.549, p<.05) and those aged 16 or older (OR=0.291, p<.05) sleep less, as well as with less consumption of tobacco (OR=0.728, p<.05) and alcohol (OR=0.837, p<.05), a lower level of sadness (OR=0.786, p<.05) and a lower tendency to use the computer for 3 hours or more a day (OR=0.829, p<.05). Conclusion: The adolescents' pattern of sleep is an important feature in adolescents lifestyles being associated to a large range of health and health compromising behaviours.