Adequate sleep duration among children and adolescents: a review of the Brazil's Report Card

Duração do sono adequada entre crianças e adolescentes: revisão para o Report Card Brazil

abstract –

This study aimed to summarize existing research examining the prevalence of adequate sleep duration or meeting sleep recommendations among Brazilian children and adolescents. A systematic review was conducted on eight databases. The criteria for inclusion were original research, samples including Brazilian children and adolescents (age 0–18), studies that reported variables regarding sleep duration using both objective or subjective measures, school- or population-based surveys with random sampling, and cross-sectional or cohort studies. Of the 54 articles included, only 27 used data from different studies. Most of the studies were conducted in the southern region (n = 17) with only two studies having a nationally representative sample. Two studies included children below age five, and the age group most investigated was adolescents (>10 years old). A majority of the studies used a self-reported questionnaire and showed variability in the cutoff point applied for adequate sleep duration with the most reported being ≥8 hours. The proportion of adolescents who met recommendations or had adequate sleep duration ranged from 15% to 89%. Among children, the prevalence ranged from 17% to 95%. The least variability was observed among toddlers, ranging from 93% to 95%. No consistent gender differences were observed among the gender-stratified groups of children and adolescents across the studies. It can be observed that, because of the wide range of results and the lack of data with national representativeness, the prevalence of sufficient sleep among young people aged below 18 remains undefined in Brazil.

Keywords:
Adolescent; Children; Preschool; Epidemiology; Sleep

resumo –

Objetivou-se resumir os estudos existentes que examinaram a prevalência de duração adequada do sono ou atendimento às recomendações de sono entre crianças e adolescentes brasileiros. Uma revisão sistemática foi realizada em oito bases de dados. Os critérios de inclusão foram pesquisas originais, amostras incluindo crianças e adolescentes brasileiros (de 0 a 18 anos), estudos que relataram variáveis ​​relacionadas à duração do sono usando medidas objetivas ou subjetivas, pesquisas baseadas na escola ou na população com amostragem aleatória e transversal ou estudos de coorte. Dos 54 artigos incluídos, apenas 27 utilizaram dados de estudos diferentes. A maioria dos estudos foi realizada na região sul (n = 17), com apenas dois estudos tendo uma amostra representativa nacionalmente. Dois estudos incluíram crianças menores de cinco anos, e a faixa etária mais investigada foi de adolescentes (> 10 anos). A maioria dos estudos utilizou um questionário autorreferido e mostrou variabilidade no ponto de corte aplicado para a duração adequada do sono com a maioria relatada sendo ≥8 horas. A proporção de adolescentes que cumpriram as recomendações ou tiveram uma duração de sono adequada variou de 15% a 89%. Entre as crianças, a prevalência variou de 17% a 95%. A menor variabilidade foi observada entre as crianças, variando de 93% a 95%. Nenhuma diferença de gênero consistente foi observada entre os grupos. Observa-se que, pela ampla variabilidade de resultados e pela carência de dados com representatividade nacional, a prevalência de sono suficiente em jovens com menos de 18 anos permanece indefinida no Brasil.

Palavras-chave:
Adolescentes; Crianças; Pré-escolares; Epidemiologia; Sono

INTRODUCTION

Sleep is an essential component of human health and plays an important role in several physiological processes, such as hormone secretion and energy balance¹,², regulating mood, attention, and behaviors³. Healthy and adequate sleep is associated with reduced body mass, better diet, and improved mental health (e.g., better regulatory emotion), which is essential to promote the learning process among children and adolescents⁴,⁵. Conversely, sleep deprivation is a risk factor for health conditions, such as obesity and depression⁶.

In recent decades, there has been a significant reduction in the sleep duration of children and adolescents, making the monitoring of sleep behavior indispensable in this target population⁷. Therefore, age-based sleep guidelines have been created to prevent and reduce the burden of sleep deprivation (e.g., National Sleep Foundation—NSF from the USA⁸—and the Canadian 24-hour Movement Guidelines⁹). These guidelines provide similar recommendations for children and adolescents according to age groups as follows: school-aged children (5–13) and adolescents (14–17) are recommended to sleep 9–11 hours and 8–10 hours per night, respectively. Moreover, the guidelines are shown to be specific for infants aged less than a year old (NSF recommends 12–15 hours while the Canadian guidelines recommend 12–16 hours), toddlers aged 1–2 (11–14 hours), and preschoolers aged 3–4 (10–13 hours).

Studies from various countries have monitored the prevalence of sufficient sleep among young people with substantial distinctions between nations. In Canada, around 60% of children and 70% of adolescents sleep the number of hours recommended for their age group. In the USA, this prevalence dropped to 40% for children and 30% for adolescents. However, in Brazil, there are no national sleep guidelines, and studies investigating sleep deprivation in Brazilian children and adolescents have local representativeness and are based on no standardized recommendations or even on adults’ cutoff points for adequate sleep duration. Accordingly, the present review seeks to summarize representative and standardized evidence related to sleep duration among Brazilian children and adolescents in order to accurately assess the current national scenario. Moreover, this is the first entry of sleep parameters to the Report Card Brazil, allowing it to cover the complete spectrum of 24-hour movement behaviors (i.e., physical activity, sedentary behavior, and sleep). Therefore, this review aims to summarize studies that analyzed the prevalence of adequate sleep duration or meeting the existing recommendations in Brazilian children and adolescents up to 18 years of age.

METHOD

Measured outcome

This systematic review included sleep duration as the outcome and involved articles that have quantified sleep duration as continuous (e.g., hours or minutes per night) or categorical (e.g., prevalence of adequate sleep) measures independent of the cutoff points and recommendations considered in the study.

Study search strategies

A systematic search was conducted in August 2020 in the following electronic databases: Medline (PubMed), Scopus, Web of Science (Web of Knowledge), EMBASE, PsycINFO, CINAHL, SciELO, and LILACS (Literatura Latino-Americana em Ciências da Saúde). The search strategy included four groups of descriptors: concept (sleep), context (country or nationality), population (young people < 18 years), and sleep duration evaluation methods (see Supplementary File 4). The Boolean operator "AND" was used for combinations among descriptor groups, and “OR” was used for intragroup combinations. The truncation symbols ($, *, or "") specific to each database were also used to increase the range of searches for descriptor variations. Searches were conducted with descriptors in English and Portuguese (in databases that are available: LILACS and SciELO). The search of the electronic databases was supplemented by a personal library and a screening of the reference list of included articles in order to identify potentially relevant titles.

Identification of eligible studies

Selection criteria

The eligibility criteria in this review were (I) original research articles published in peer-reviewed journals, (II) samples with Brazilian children and adolescents aged 0–18 years old (or a mean age within these ranges or separate data for individuals in this age range), (III) articles that reported variables regarding sleep duration (e.g., hours per night, minutes per night, prevalence of adequate sleep duration [despite the cut-point used]) using objective (i.e., polysomnography or actigraphy) or subjective (i.e., self-, proxy-, or parent/guardian-report) measures, (IV) population- or school-based surveys with random sampling, and (V) cross-sectional or cohort studies.

Selection process

The initial analysis was performed based on the reading of the manuscript’s titles, and, when there was doubt regarding the inclusion of the study, a reading of the abstract was carried out. After this analysis, the articles were screened based on full-text reading and subsequently analyzed according to the established selection criteria. All the processes were conducted by two independent peers (peer 1: LM and MK; peer 2: GM and ML). The peers screened an equal number of references (50%), and disagreements between reviewers were resolved by consensus.

Data extraction and synthesis

The included articles were equally divided and extracted by the two mentioned peers. The prevalence of adequate sleep duration was extracted, and the cutoff point adopted in each article was preserved. In cases in which the authors did not define an adequate sleep category (e.g., <6 h/d, 6–8 h/d, and >8h/d), the one that characterized the age-based sleep guidelines⁹ was extracted. In addition, articles from the same study were identified to avoid duplication of information.

Information extracted comprised i) basic descriptive information about the article (e.g. author, title); ii) sample size; iii) age range; iv) sleep measurement instrument or questionnaire, classified as “defined” when a valid and established questionnaire was nominated (e.g., Pittsburgh Sleep Quality Index), “undefined” when no information regarding the sleep duration measurement was provided, or “undefined-reproductible” when the questionnaire was not nominated but authors fully described the questions used for assessing sleep duration; v) sleep duration guidelines and/or sleep duration categories/cutoff points adopted; and vi) the results (by gender and age when provided) of the prevalence of adequate sleep (according to the authors) or the duration of sleep presented continuously.

The overall prevalence by gender and age (when reported by the authors) of adequate sleep duration and/or meeting sleep duration recommendations was extracted. The results of the studies were presented in alphabetical and chronological order by first author name and year of publication, respectively. The results were organized to present methodological aspects (Supplementary File 1) and the prevalence of sleep (Supplementary File 2) of the included studies. In the case of articles reporting findings from the same study or sample (e.g., 10 articles reported ISCOLE findings), the article with the largest sample size for sleep data was selected for study description.

RESULTS

The searches found 5,307 articles, 54 of which were identified and included in the review (no article was included from the screening of the reference list). Figure 1 presents a summary of the screening process. The articles were published between 2005 and 2019, but most were published after 2015 (n = 42). While 54 articles were identified, some used the same study sample: 10 articles used data from ISCOLE¹⁰–¹⁹, 3 from ERICA²⁰-²², 7 from the “Brazilian Guide for Evaluating Physical Fitness Related to Health and Life Habits”²³-²⁹, 2 from BRACAH³⁰,³¹, 2 from COMPAC³²,³³, 2 from “1993 Pelotas Birth Cohort”³⁴,³⁵, and 4 from “2004 Pelotas Birth Cohort³⁶–³⁹.” Three studies were conducted with the same sample of adolescents from the city of Maravilha in Santa Catarina²⁴,⁴⁰–⁴², and another three were conducted with the same sample of adolescents from the city of Teutônia in Rio Grande do Sul⁴³–⁴⁵. The other articles did not report their study name or were identified as having unique samples (n = 18). Overall, 27 different studies were identified among the 54 reports. Detailed information on all studies is available in the supplementary file (Supplementary File 1).

Figure 1
Flowchart of the studies through the phases of the systematic review.

The majority of studies were conducted in southern Brazil (n = 17)²⁸,³⁰,³¹,³³,³⁵,³⁹,⁴³,⁴⁶–⁵⁵ followed by the southeast (n = 3)¹⁵,⁵⁶,⁵⁷ and northeast (n = 5)⁵⁸–⁶². No studies were available from cities in the mid-west or northern regions of Brazil. Two studies were from a national sample, contemplating all five Brazilian macro-regions²⁰,⁶³. Studies conducted with adolescents (>10 years old) were the most frequent (n = 16)²¹,²⁹,³¹,³²,³⁵,⁴⁰,⁴⁴,⁴⁷,⁴⁹,⁵⁰,⁵³,⁵⁵,⁵⁸,⁶⁰–⁶² followed by those with children aged 5–10 (n = 6) ¹⁵,⁴⁶,⁵¹,⁵²,⁵⁶,⁵⁹ and infants and/or toddlers (n = 2) (<5 years old)³⁶,⁵⁴. Three studies analyzed more than one age group⁴⁸,⁵⁷,⁶³.

Regarding instruments for measuring sleep duration, one study used accelerometers (ActiGraph GT3X+)¹⁵, and all the others used self-reported or parent-reported questionnaires³⁶,⁴⁸,⁵²,⁵⁴,⁶³. Only five studies were classified as “Defined” and used the following questionnaires: Brief Infant Sleep Questionnaire (BISQ)⁶², The Sleep Disturbance Scale for Children (SDSC)⁵⁶,⁶³, Pittsburgh Sleep Quality Index (PSQI)⁶³, and Back Pain and Body Posture Evaluation Instrument (BackPE)⁴⁴. The other studies that used questionnaires did not report the name of the instrument used and were classified as “Undefined-Reproductible” (n = 12) or “Undefined” (n = 13).

The prevalence of compliance with sleep recommendations/adequate sleep duration was available in 22 studies (30 articles) (Supplementary File 2). Although some studies utilized the same study/sample, different cutoffs were adopted across them. Eight articles applied sleep duration cutoffs proposed by health organizations to describe sleep compliance (24-hour Canadian guideline, National Sleep Foundation) ¹⁶,²⁰,²⁵,²⁷,³¹,³²,³⁴,⁵³. Other studies classified sleep duration as adequate or inadequate based on varying cutoff values with ≥8 hours per day as the most frequent criteria (n = 13).

The prevalence of meeting the recommended sleep duration ranged from 13.1% to 96.5%. The least variability was observed among toddlers, ranging from 93% to 95%. In children, the prevalence varied from 17% to 95%, and in adolescents, it ranged from 15% to 89% (Figure 2). Studies with data from all the five major Brazilian regions reported a high prevalence of sufficient sleep among children (95.1%)⁶³ and adolescents (82.2%²⁰ and 89.2%⁶³). However, studies conducted specifically in the northwest showed lower compliance with the recommendations identified among adolescents. The results of the south and southeast regions varied considerably; however, data available from the southeast included only children (Figure 2).

Figure 2
Prevalence of meeting recommendations or having adequate sleep according to age group and Brazilian macro-regions. Note: Letters refer to cutoff points applied: a (≥10h/d); b (≥9h/d); c (>8h/d); d (>10h/d); e (≥7h/d); f (>7h/d); g (8-9h/d); h (≥6h/d); i (9–11h/d); studies with no letter applied the ≥8h/d cutoff point.

Figure 3 shows the prevalence of meeting the recommendations according to sex, separately for each age group. No consistent sex difference was observed among the sex-stratified groups of children and adolescents across the studies. There were no studies stratified by sex in the pre-infant and toddler age groups.

Figure 3
Prevalence of meeting recommendations or having adequate sleep according to age group by sex.

Studies showing only continuous sleep duration measurements are presented in Supplementary File 3. Briefly, five studies did not report the prevalence of adequate sleep duration; instead, they reported the mean sleep duration per night. One study was conducted with toddlers (12 months old)⁵⁴, three with children (7–13 years old)⁴⁶,⁴⁸,⁵⁷, and one with adolescents (14–19 years old)⁴⁷. The average sleep duration of toddlers was 9.5 hours per night (no standard deviation was reported). For children, the mean sleep duration ranged from 9.9 to 10.2 hours per night while, in adolescents, the sleep duration was of 7.9 ± 1.8 hours on school days and 9.2 ± 1.8 on non-school days.

DISCUSSION

This systematic review aimed to verify the sleep duration among children and adolescents in Brazil. Accordingly, 54 articles, which accounted for 27 different studies, were included. The findings showed a higher predominance of studies in the southern region of Brazil, few studies with children less than six years of age, and higher methodological variability of the instruments used to examine sleep duration. In the present review, there was a wide range of the proportion of children and adolescents (from 13.1% to 96.5%) who had adequate sleep duration or who met any institutional recommendations.

Part of this variability may be explained by the use of different cutoff points for classifying sleep duration and the use of questionnaires with different recall periods with most of them classified as undefined-reproductible or undefined. Meanwhile, only ISCOLE, which is a multicenter study, assessed sleep duration using an accelerometer. This reflects the financial burden that Brazilian universities and researchers face when acquiring research-grade accelerometers, making it impractical to use them in largescale epidemiological studies.

This review highlights that there is no consensus in terms of the sleep time cutoff point among Brazilian studies, which inhibits comparability of the results, and provides overestimated proportions of adequate sleep duration in children and adolescents. Less than half of the reviewed studies stated the recommendation guidelines adopted, and, among these, the NSF guidelines⁸ were the most frequent, although often confusing. For instance, most of the studies adopted ≥8 hours as sufficient sleep for adolescents younger than 13 years old while the NSF recommends 9–11 hours of sleep⁸ and the American Academy of Sleep Medicine recommends 9–12 hours⁶⁴. Similarly, adopting ≥10 hours represents a misclassification for toddlers aged 1–2 years old, who should have 11–14 hours of sleep⁸,⁶⁴. This can be attributed to the stratification of participants in age groups according to the distribution of data or an arbitrary decision instead of grouping them by age ranges compatible with the current sleep recommendations. Applying different cutoff points leads to a systematic overestimation of the proportion of adequate sleep among children and adolescents, masking those who may be experiencing attention or learning problems⁴,⁵ and facing an increased risk of obesity, diabetes, and depression⁶. This methodological concern may be overcome by reaching a consensus for sufficient sleep duration based on any previous institutional guidelines (e.g., WHO, NSF, Canadian/Australian Guidelines) and endorsing it in Brazilian pediatric research.

This review underscores the lack of sleep duration data representative of the country. Only one study reported the prevalence of sufficient sleep duration in Brazilian adolescents²⁰, but there is no -nationally representative evidence for toddlers and children. Meanwhile, the National School-Based Health Survey (PeNSE)⁶⁵, which monitors health-related factors among schoolchildren in Brazil every three years and is supported by the government, does not measure sleep duration. Given this gap, including pediatric sleep surveillance in the agenda for future epidemiological nationwide surveys is paramount.

Despite this review demonstrating a wide variability in the prevalence of adequate sleep or meeting a guidelines recommendation between studies, the pattern was not observed among studies with toddlers. From two studies with toddler data, approximately 92% of participants achieved adequate sleep or met the recommendations. These results are slightly larger than those of other countries such as Canada⁶⁶ and Australia⁶⁷, where values were around 83% and 88%, respectively. For the other age groups, variability was more evident. When considering studies with children, one study demonstrated that more than 90% of children met a sleep recommendation⁶³, and another showed less than 30%⁵². A study conducted with children aged 9–11 across 12 countries observed a prevalence of 42% for meeting the Canadian Guidelines among children from these countries, with countries such as Australia and the UK showing the highest prevalence (76%) while China had the lowest (15%)¹⁶. Adolescents were the most investigated population among the included studies, which probably explains the highly heterogeneous results in this age group. A study by Araujo et al. (2017) showed that only 15% of adolescents met the recommendations of sleep hours while studies by Almeida and Nunes (2019) showed that approximately 90% of them adhered to this recommendation. Some countries show a low prevalence of adequate sleep, such as the USA, where the prevalence of sufficient sleep is around 32%⁶⁸, or China⁶⁹, showing only 8% of adolescents meeting the Canadian guidelines. However, in Canada, the results are opposite to the prevalence of sufficient sleep ranging from 66% to 74%⁷⁰, and similar results were found in the UK⁷¹.

The prevalence of adequate sleep duration in children varied similarly within the Brazilian regions. Although Brazil is marked with social and health inequalities⁷², the observed within-region differences were based on studies that applied distinct cutoff thresholds for adequate sleep duration, which may partially explain the differences. In this study, a lower prevalence of adequate sleep duration was found among adolescents from the northeast than among those from the southeast and southern regions. Brazil is the size of a continent, and these findings may be explained not only by individual and contextual factors but also by environmental parameters. According to evidence from South America⁷³, latitude is observed to strongly affect sleep patterns, leading to longer sleep duration with increasing latitude. Latitude affects the variation of daylight hours and locations near the Equator, such as Northeast Brazil, have approximately 12 hours of daylight all over the year, and the sun rises earlier in the morning.

This is the first study to compile evidence of adequate sleep duration among Brazilian children and adolescents. Another strength is the summary of findings per country region, which highlights the differences within the population given Brazil’s size. However, this study has certain limitations that need to be acknowledged. The screening and extraction processes were conducted by two independent peers, and no calibration was performed between them to confirm that the interpretations were the same for all screened parameters. Despite this, the inclusion criteria were established among the group of reviewers, and all members were in accordance with the established criteria, and the criteria were reinforced at all stages of the process through periodic meetings. Owing to the nature of this study, publication bias may arise, and conclusions were limited to the available evidence. Therefore, the findings should be interpreted with caution because of the possibility of result bias (e.g., higher prevalence rates in recent studies than in older studies).

CONCLUSIONS

From this review, we can observe that, owing to the wide-ranging results and the lack of data with national representativeness, the prevalence of sufficient sleep among young people aged below 18 years of age is undefined in Brazil. These data also emphasize that researchers need to recognize that adult cutoffs do not apply to the pediatric population. It is necessary to standardize what is enough sleep for the infant-juvenile population based on cutoff points already published and established by various health organizations or even by creating a guideline for the Brazilian population recognizing the sociocultural aspects of the country.

COMPLIANCE WITH ETHICAL STANDARDS

Supplementary Material

Supplementary material accompanies this paper.

Supplementary File 1 Free access in https://osf.io/eu5kd/ Supplementary File 2 Free access in https://osf.io/eu5kd/ Supplementary File 3 Free access in https://osf.io/eu5kd/ Supplementary File 4 Free access in https://osf.io/eu5kd/

This materials are available as part of the online article from http://www.scielo.br/rbcdh

• How to cite this articleMalheiros LEA, Knebel MTG, Lopes MVV, Mello GT, Barbosa Filho VC, Silva KS. Adequate sleep duration among children and adolescents: a review of the Brazil's Report Card. Rev Bras Cineantropom Desempenho Hum 2021, 23:e82644. DOI: https://doi.org/10.1590/1980-0037.2021v23e82644
• Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. This study was funded by the authors.

REFERENCES

• ¹
  Morgan D, Tsai SC. Sleep and the endocrine system. Crit Care Clin 2015;31(3):403-18. http://dx.doi.org/10.1016/j.ccc.2015.03.004 PMid:26118912.
  » http://dx.doi.org/10.1016/j.ccc.2015.03.004
• ²
  Shukla C, Basheer R. Metabolic signals in sleep regulation: recent insights. Nat Sci Sleep 2016;8:9-20. PMid:26793010.
• ³
  Shochat T, Cohen-Zion M, Tzischinsky O. Functional consequences of inadequate sleep in adolescents: a systematic review. Sleep Med Rev 2014;18(1):75-87. http://dx.doi.org/10.1016/j.smrv.2013.03.005 PMid:23806891.
  » http://dx.doi.org/10.1016/j.smrv.2013.03.005
• ⁴
  Roberts RE, Roberts CR, Duong HT. Sleepless in adolescence: prospective data on sleep deprivation, health and functioning. J Adolesc 2009;32(5):1045-57. http://dx.doi.org/10.1016/j.adolescence.2009.03.007 PMid:19361854.
  » http://dx.doi.org/10.1016/j.adolescence.2009.03.007
• ⁵
  Anderson B, Storfer-Isser A, Taylor HG, Rosen CL, Redline S. Associations of executive function with sleepiness and sleep duration in adolescents. Pediatrics 2009;123(4):e701-7. http://dx.doi.org/10.1542/peds.2008-1182 PMid:19336360.
  » http://dx.doi.org/10.1542/peds.2008-1182
• ⁶
  Chaput JP, Gray CE, Poitras VJ, Carson V, Gruber R, Olds T, et al. Systematic review of the relationships between sleep duration and health indicators in school-aged children and youth. Appl Physiol Nutr Metab 2016;41(6, Suppl. 3):S266-82. http://dx.doi.org/10.1139/apnm-2015-0627 PMid:27306433.
  » http://dx.doi.org/10.1139/apnm-2015-0627
• ⁷
  Matricciani L, Olds T, Petkov J. In search of lost sleep: secular trends in the sleep time of school-aged children and adolescents. Sleep Med Rev 2012;16(3):203-11. http://dx.doi.org/10.1016/j.smrv.2011.03.005 PMid:21612957.
  » http://dx.doi.org/10.1016/j.smrv.2011.03.005
• ⁸
  Hirshkowitz M, Whiton K, Albert SM, Alessi C, Bruni O, DonCarlos L, et al. National Sleep Foundation’s sleep time duration recommendations: methodology and results summary. Sleep Health 2015;1(1):40-3. http://dx.doi.org/10.1016/j.sleh.2014.12.010 PMid:29073412.
  » http://dx.doi.org/10.1016/j.sleh.2014.12.010
• ⁹
  Tremblay MS, Carson V, Chaput JP, Connor Gorber S, Dinh T, Duggan M, et al. Canadian 24-hour movement guidelines for children and youth: an integration of physical activity, sedentary behaviour, and sleep. Appl Physiol Nutr Metab 2016;41(6, Suppl. 3):S311-27. http://dx.doi.org/10.1139/apnm-2016-0151 PMid:27306437.
  » http://dx.doi.org/10.1139/apnm-2016-0151
• ¹⁰
  Chaput JP, Katzmarzyk PT, LeBlanc AG, Tremblay MS, Barreira TV, Broyles ST, et al. Associations between sleep patterns and lifestyle behaviors in children: an international comparison. Int J Obes Suppl 2015;5(S2, Suppl. 2):S59-65. http://dx.doi.org/10.1038/ijosup.2015.21 PMid:27152187.
  » http://dx.doi.org/10.1038/ijosup.2015.21
• ¹¹
  Chaput JP, Barnes JD, Tremblay MS, Fogelholm M, Hu G, Lambert EV, et al. Inequality in physical activity, sedentary behaviour, sleep duration and risk of obesity in children: a 12-country study. Obes Sci Pract 2018;4(3):229-37. http://dx.doi.org/10.1002/osp4.271 PMid:29951213.
  » http://dx.doi.org/10.1002/osp4.271
• ¹²
  Dumuid D, Maher C, Lewis LK, Stanford TE, Martín Fernández JA, Ratcliffe J, et al. Human development index, children’s health-related quality of life and movement behaviors: a compositional data analysis. Qual Life Res 2018;27(6):1473-82. http://dx.doi.org/10.1007/s11136-018-1791-x PMid:29362939.
  » http://dx.doi.org/10.1007/s11136-018-1791-x
• ¹³
  Gomes TN, Katzmarzyk PT, Hedeker D, Fogelholm M, Standage M, Onywera V, et al. Correlates of compliance with recommended levels of physical activity in children. Sci Rep 2017;7(1):16507. http://dx.doi.org/10.1038/s41598-017-16525-9 PMid:29184164.
  » http://dx.doi.org/10.1038/s41598-017-16525-9
• ¹⁴
  Katzmarzyk PT, Barreira TV, Broyles ST, Champagne CM, Chaput JP, Fogelholm M, et al. Relationship between lifestyle behaviors and obesity in children ages 9-11: results from a 12-country study. Obesity 2015;23(8):1696-702. http://dx.doi.org/10.1002/oby.21152 PMid:26173093.
  » http://dx.doi.org/10.1002/oby.21152
• ¹⁵
  Lin Y, Tremblay MS, Katzmarzyk PT, Fogelholm M, Hu G, Lambert EV, et al. Temporal and bi-directional associations between sleep duration and physical activity/sedentary time in children: an international comparison. Prev Med 2018;111:436-41. http://dx.doi.org/10.1016/j.ypmed.2017.12.006 PMid:29223790.
  » http://dx.doi.org/10.1016/j.ypmed.2017.12.006
• ¹⁶
  Roman-Viñas B, Chaput JP, Katzmarzyk PT, Fogelholm M, Lambert EV, Maher C, et al. Proportion of children meeting recommendations for 24-hour movement guidelines and associations with adiposity in a 12-country study. Int J Behav Nutr Phys Act 2016;13(1):123. http://dx.doi.org/10.1186/s12966-016-0449-8 PMid:27887654.
  » http://dx.doi.org/10.1186/s12966-016-0449-8
• ¹⁷
  Sampasa-Kanyinga H, Standage M, Tremblay MS, Katzmarzyk PT, Hu G, Kuriyan R, et al. Associations between meeting combinations of 24-h movement guidelines and health-related quality of life in children from 12 countries. Public Health 2017;153:16-24. http://dx.doi.org/10.1016/j.puhe.2017.07.010 PMid:28818582.
  » http://dx.doi.org/10.1016/j.puhe.2017.07.010
• ¹⁸
  Thivel D, Tremblay MS, Katzmarzyk PT, Fogelholm M, Hu G, Maher C, et al. Associations between meeting combinations of 24-hour movement recommendations and dietary patterns of children: a 12-country study. Prev Med 2019;118:159-65. http://dx.doi.org/10.1016/j.ypmed.2018.10.025 PMid:30393016.
  » http://dx.doi.org/10.1016/j.ypmed.2018.10.025
• ¹⁹
  Manyanga T, Barnes JD, Tremblay MS, Katzmarzyk PT, Broyles ST, Barreira TV, et al. No evidence for an epidemiological transition in sleep patterns among children: a 12-country study. Sleep Health. 2018;4(1):87-95. http://dx.doi.org/10.1016/j.sleh.2017.10.010.
  » https://doi.org/10.1016/j.sleh.2017.10.010
• ²⁰
  Oliveira G, Silva TLND, Silva IBD, Coutinho ESF, Bloch KV, Oliveira ERA. Aggregation of cardiovascular risk factors: alcohol, smoking, excess weight, and short sleep duration in adolescents in the ERICA study. Cad Saude Publica 2019;35(12):e00223318. http://dx.doi.org/10.1590/0102-311x00223318 PMid:31800793.
  » http://dx.doi.org/10.1590/0102-311x00223318
• ²¹
  Abreu GA, Silva TLND, Teixeira LR, Bloch KV. Quality analysis of self-reported information on sleep duration in schoolchildren in the Study of Cardiovascular Risk Factors in Adolescents (ERICA). Cad Saude Publica 2019;35(10):e00152918. http://dx.doi.org/10.1590/0102-311x00152918 PMid:31644678.
  » http://dx.doi.org/10.1590/0102-311x00152918
• ²²
  Guedes LG, Abreu GA, Bloch KV. Self-reported nocturnal sleep duration and glycosylated hemoglobin A in the Study of cardiovascular Risks in Adolescents (ERICA). Sleep Med 2018;47:60-5. http://dx.doi.org/10.1016/j.sleep.2018.03.013 PMid:29758395.
  » http://dx.doi.org/10.1016/j.sleep.2018.03.013
• ²³
  Lima TR, Silva DAS. Association between sports practice and physical education classes and lifestyle among adolescents. Hum Mov Sci 2019;20(3):48-55.
• ²⁴
  Lima TR, Silva DAS. Prevalence of physical activity among adolescents in southern Brazil. J Bodyw Mov Ther. 2018;22(1):57-63. http://dx.doi.org/10.1016/j.jbmt.2017.03.022 PMid:29332758.
  » http://dx.doi.org/10.1016/j.jbmt.2017.03.022
• ²⁵
  Gomes Felden ÉP, Barbosa DG, Junior GJF, Santos MO, Pelegrini A, Silva DAS. Factors associated with sleep duration in Brazilian high school students. Chronobiol Int 2017;34(6):773-81. http://dx.doi.org/10.1080/07420528.2017.1323759 PMid:28537765.
  » http://dx.doi.org/10.1080/07420528.2017.1323759
• ²⁶
  Lima TR, Silva DAS. Association of sleep quality with sociodemographic factors and lifestyle in adolescents from southern Brazil. World J Pediatr 2018;14(4):383-91. http://dx.doi.org/10.1007/s12519-018-0136-8 PMid:29536340.
  » http://dx.doi.org/10.1007/s12519-018-0136-8
• ²⁷
  Lima TR, Sousa GR, Castro JAC, Silva DAS. Simultaneous presence of excess weight and insufficient hours of sleep in adolescents: prevalence and related factors. J Hum Growth Dev 2017;27(2):148-57. http://dx.doi.org/10.7322/jhgd.115987
  » http://dx.doi.org/10.7322/jhgd.115987
• ²⁸
  Meyer C, Barbosa DG, Junior GJF, Andrade RD, Silva DAS, Pelegrini A, et al. Proposal of cutoff points for pediatric daytime sleepiness scale to identify excessive daytime sleepiness. Chronobiol Int 2018;35(3):303-11. http://dx.doi.org/10.1080/07420528.2017.1400980 PMid:29144155.
  » http://dx.doi.org/10.1080/07420528.2017.1400980
• ²⁹
  Meyer C, Ferrari GJ Jr, Andrade RD, Barbosa DG, da Silva RC, Pelegrini A, et al. Factors associated with excessive daytime sleepiness among Brazilian adolescents. Chronobiol Int 2019;36(9):1240-8. http://dx.doi.org/10.1080/07420528.2019.1633661 PMid:31296060.
  » http://dx.doi.org/10.1080/07420528.2019.1633661
• ³⁰
  Collese TS, De Moraes ACF, Fernández-Alvira JM, Michels N, De Henauw S, Manios Y, et al. How do energy balance-related behaviors cluster in adolescents? Int J Public Health 2019;64(2):195-208. http://dx.doi.org/10.1007/s00038-018-1178-3 PMid:30511170.
  » http://dx.doi.org/10.1007/s00038-018-1178-3
• ³¹
  Forkert ECO, Moraes ACFD, Carvalho HB, Manios Y, Widhalm K, González-Gross M, et al. Skipping breakfast is associated with adiposity markers especially when sleep time is adequate in adolescents. Sci Rep 2019;9(1):6380. http://dx.doi.org/10.1038/s41598-019-42859-7 PMid:31011180.
  » http://dx.doi.org/10.1038/s41598-019-42859-7
• ³²
  Hoefelmann LP, Lopes AS, Silva KS, Moritz P, Nahas MV. Sociodemographic factors associated with sleep quality and sleep duration in adolescents from Santa Catarina, Brazil: what changed between 2001 and 2011? Sleep Med 2013;14(10):1017-23. http://dx.doi.org/10.1016/j.sleep.2013.05.015 PMid:23890599.
  » http://dx.doi.org/10.1016/j.sleep.2013.05.015
• ³³
  Hoefelmann LP, Silva KS, Lopes ADS, Cabral LGA, Bertuol C, Bandeira ADS, et al. Associação entre comportamento não saudável e qualidade e duração do sono em adolescentes. Rev Bras Cineantropom Desempenho Hum 2015;17(3):318. http://dx.doi.org/10.5007/1980-0037.2015v17n3p318
  » http://dx.doi.org/10.5007/1980-0037.2015v17n3p318
• ³⁴
  Schäfer AA, Domingues MR, Dahly DL, Meller FO, Gonçalves H, Wehrmeister FC, et al. Sleep duration trajectories and body composition in adolescents: prospective birth cohort study. PLoS One 2016;11(3):e0152348. http://dx.doi.org/10.1371/journal.pone.0152348 PMid:27010312.
  » http://dx.doi.org/10.1371/journal.pone.0152348
• ³⁵
  Schäfer AA, Domingues MR, Dahly DL, Meller FO, Gonçalves H, Wehrmeister FC, et al. Correlates of self-reported weekday sleep duration in adolescents: the 18-year follow-up of the 1993 Pelotas (Brazil) Birth Cohort Study. Sleep Med 2016;23:81-8. http://dx.doi.org/10.1016/j.sleep.2016.02.013 PMid:27692281.
  » http://dx.doi.org/10.1016/j.sleep.2016.02.013
• ³⁶
  Halal CSE, Matijasevich A, Howe LD, Santos IS, Barros FC, Nunes ML. Short sleep duration in the first years of life and obesity/overweight at age 4 years: a birth cohort study. J Pediatr 2016;168:99-103. http://dx.doi.org/10.1016/j.jpeds.2015.09.074 PMid:26541426.
  » http://dx.doi.org/10.1016/j.jpeds.2015.09.074
• ³⁷
  Netsi E, Santos IS, Stein A, Barros FC, Barros AJD, Matijasevich A. A different rhythm of life: sleep patterns in the first 4 years of life and associated sociodemographic characteristics in a large Brazilian birth cohort. Sleep Med 2017;37:77-87. http://dx.doi.org/10.1016/j.sleep.2017.06.001 PMid:28899545.
  » http://dx.doi.org/10.1016/j.sleep.2017.06.001
• ³⁸
  Santos IS, Mota DM, Matijasevich A. Epidemiology of co-sleeping and nighttime waking at 12 months in a birth cohort. J Pediatr 2008;84(2):114-22. http://dx.doi.org/10.2223/JPED.1766 PMid:18372938.
  » http://dx.doi.org/10.2223/JPED.1766
• ³⁹
  Santos IS, Matijasevich A, Domingues MR. Maternal caffeine consumption and infant nighttime waking: prospective cohort study. Pediatrics 2012;129(5):860-8. http://dx.doi.org/10.1542/peds.2011-1773 PMid:22473365.
  » http://dx.doi.org/10.1542/peds.2011-1773
• ⁴⁰
  Felden ÉPG, Filipin D, Barbosa DG, Andrade RD, Meyer C, Louzada FM. Factors associated with short sleep duration in adolescents. Rev Paul Pediatr 2016;34(1):64-70. http://dx.doi.org/10.1016/j.rpped.2015.05.006 PMid:26559604.
  » http://dx.doi.org/10.1016/j.rpped.2015.05.006
• ⁴¹
  Felden ÉPG, Barbosa DG, Ferrari GJ Jr, Andrade RD, Filipin D, Pelegrini A, et al. Padrões de sono e sonolência diurna: comparação entre adolescentes do interior e da região metropolitana. Cad Saude Colet 2018;26(2):170-7. http://dx.doi.org/10.1590/1414-462x201800020409
  » http://dx.doi.org/10.1590/1414-462x201800020409
• ⁴²
  Felden ÉPG, Filipin D, Barbosa DG, Andrade RD, Meyer C, Beltrame TS, et al. Adolescentes com sonolência diurna excessiva passam mais tempo em comportamento sedentário. Rev Bras Med Esporte 2016;22(3):186-90. http://dx.doi.org/10.1590/1517-869220162203147290
  » http://dx.doi.org/10.1590/1517-869220162203147290
• ⁴³
  Noll M, Candotti CT, Tiggemann CL, Schoenell MCW, Vieira A. Prevalência de hábitos posturais inadequados de escolares do Ensino Fundamental da cidade de Teutônia: um estudo de base populacional. Rev Bras Ciênc Esporte 2013;35(4):983-1004. http://dx.doi.org/10.1590/S0101-32892013000400012
  » http://dx.doi.org/10.1590/S0101-32892013000400012
• ⁴⁴
  Noll M, Candotti CT, da Rosa BN, Loss JF. Back pain prevalence and associated factors in children and adolescents: an epidemiological population study. Rev Saúde Publ 2016;50:10.
• ⁴⁵
  Noll M, Candotti CT, Rosa BN, Schoenell MCW, Tiggemann CL, Loss JF. Back pain and the postural and behavioral habits of students in the municipal school network of Teutônia, Rio Grande do Sul. J Hum Growth Dev 2013;23(2):1-10. http://dx.doi.org/10.7322/jhgd.61234
  » http://dx.doi.org/10.7322/jhgd.61234
• ⁴⁶
  Bach SL, Moreira FP, Goettems ML, Brancher LC, Oses JP, da Silva RA, et al. Salivary cortisol levels and biological rhythm in schoolchildren with sleep bruxism. Sleep Med 2019;54:48-52. http://dx.doi.org/10.1016/j.sleep.2018.09.031 PMid:30529777.
  » http://dx.doi.org/10.1016/j.sleep.2018.09.031
• ⁴⁷
  Ferrari GJ Jr, Barbosa DG, Andrade RD, Pelegrini A, Beltrame TS, Felden ÉPG. Subjective sleep need and daytime sleepiness in adolescents. Rev Paul Pediatr 2019;37(2):209-16. http://dx.doi.org/10.1590/1984-0462/;2019;37;2;00014 PMid:30810697.
  » http://dx.doi.org/10.1590/1984-0462/;2019;37;2;00014
• ⁴⁸
  Guedes DP, Desiderá RA, Gonçalves HR. Prevalence of excessive screen time and correlates factors in Brazilian schoolchildren. Rev Bras Ativ Fís Saúde 2018;23:1-10. http://dx.doi.org/10.12820/rbafs.23e0003
  » http://dx.doi.org/10.12820/rbafs.23e0003
• ⁴⁹
  Benedet J, Assis MA, Calvo MC, Andrade DF. Overweight in adolescents: exploring potential risk factors. Rev Paul Pediatr 2013;31(2):172-81. http://dx.doi.org/10.1590/S0103-05822013000200007 PMid:23828053.
  » http://dx.doi.org/10.1590/S0103-05822013000200007
• ⁵⁰
  Brandalize M, Pereira RF, Leite N, Filho GL, Louzada FM. Effect of morning school schedule on sleep and anthropometric variables in adolescents: a follow-up study. Chronobiol Int 2011;28(9):779-85. http://dx.doi.org/10.3109/07420528.2011.603452 PMid:21867369.
  » http://dx.doi.org/10.3109/07420528.2011.603452
• ⁵¹
  Corso ACT, Caldeira GV, Fiates GMR, Schmitz BAS, Ricardo GD, Vasconcelos FAG. Fatores comportamentais associados ao sobrepeso e à obesidade em escolares do Estado de Santa Catarina. Rev Bras Estud Popul 2012;29(1):117-31. http://dx.doi.org/10.1590/S0102-30982012000100008
  » http://dx.doi.org/10.1590/S0102-30982012000100008
• ⁵²
  Legnani RFS, Legnani E, Silva MP, Gasparotto GS, Bacil EDA. Clustered risk factors to health in children. Medicina 2015;48(4):328.
• ⁵³
  Lima TR, Zanelatto C, Bastos JL, Vasconcelos FAG, Silva DAS. Sociodemographic and behavioral characteristics of obese students with sleep problems in Southern Brazil. Rev Nutr 2018;31(3):311-23. http://dx.doi.org/10.1590/1678-98652018000300005
  » http://dx.doi.org/10.1590/1678-98652018000300005
• ⁵⁴
  Lopes ER, Jansen K, Quevedo LÁ, Vanila RG, Silva RA, Pinheiro RT. Depressão pós-parto e alterações de sono aos 12 meses em bebês nascidos na zona urbana da cidade de Pelotas/RS. J Bras Psiquiatr 2010;59(2):88-93. http://dx.doi.org/10.1590/S0047-20852010000200002
  » http://dx.doi.org/10.1590/S0047-20852010000200002
• ⁵⁵
  Pereira EF, Moreno C, Louzada FM. Increased commuting to school time reduces sleep duration in adolescents. Chronobiol Int 2014;31(1):87-94. http://dx.doi.org/10.3109/07420528.2013.826238 PMid:24152062.
  » http://dx.doi.org/10.3109/07420528.2013.826238
• ⁵⁶
  Silva TA, Carvalho LBC, Silva L, Medeiros M, Natale VB, Carvalho JEC, et al. Sleep habits and starting time to school in Brazilian children. Arq Neuropsiquiatr 2005;63(2B):402-6. http://dx.doi.org/10.1590/S0004-282X2005000300007 PMid:16059588.
  » http://dx.doi.org/10.1590/S0004-282X2005000300007
• ⁵⁷
  Giovaninni NP, Fuly JT, Moraes LI, Coutinho TN, Trarbach EB, Jorge AA, et al. Study of the association between 3111T/C polymorphism of the CLOCK gene and the presence of overweight in schoolchildren. J Pediatr 2014;90(5):500-5. http://dx.doi.org/10.1016/j.jped.2014.01.011 PMid:24818524.
  » http://dx.doi.org/10.1016/j.jped.2014.01.011
• ⁵⁸
  Oliveira LMFT, Silva AO, dos Santos MAM, Ritti-Dias RM, Diniz PRB. Exercício físico ou atividade física: qual apresenta maior associação com a percepção da qualidade do sono de adolescentes? Rev Paul Pediatr 2018;36(3):322-8. http://dx.doi.org/10.1590/1984-0462/;2018;36;3;00014
  » http://dx.doi.org/10.1590/1984-0462/;2018;36;3;00014
• ⁵⁹
  Alves CL, Fagundes DM, Soares PBF, Ferreira MC. Knowledge of parents/caregivers about bruxism in children treated at the pediatric dentistry clinic. Sleep Sci 2019;12(3): 185-189. http://dx.doi.org/10.5935/1984-0063.20190083 PMid:31890094.
  » http://dx.doi.org/10.5935/1984-0063.20190083
• ⁶⁰
  Silva AO, Oliveira LMFT, Santos MAM, Tassitano RM. Tempo de tela, percepção da qualidade de sono e episódios de parassonia em adolescentes. Rev Bras Med Esporte 2017;23(5):375-9. http://dx.doi.org/10.1590/1517-869220172305163582
  » http://dx.doi.org/10.1590/1517-869220172305163582
• ⁶¹
  Batista GA, Silva TND, Oliveira MR, Diniz PRB, Lopes SS, Oliveira LMFT. Association between perception of sleep quality and assimilation of content covered in class. Rev Paul Pediatr 2018;36(3):315-21. http://dx.doi.org/10.1590/1984-0462/;2018;36;3;00008 PMid:29995138.
  » http://dx.doi.org/10.1590/1984-0462/;2018;36;3;00008
• ⁶²
  Araújo EPDS, Queiroz DJM, Neves JPR, Lacerda LM, Gonçalves MDCR, Carvalho AT. Prevalence of hypovitaminosis D and associated factors in adolescent students of a capital of Northeastern Brazil. Nutr Hosp 2017;34(5):1416-23. http://dx.doi.org/10.20960/nh.1097 PMid:29280659.
  » http://dx.doi.org/10.20960/nh.1097
• ⁶³
  de Almeida GMF, Nunes ML. Sleep characteristics in Brazilian children and adolescents: a population-based study. Sleep Med X 2019;1:100007. http://dx.doi.org/10.1016/j.sleepx.2019.100007 PMid:33870166.
  » http://dx.doi.org/10.1016/j.sleepx.2019.100007
• ⁶⁴
  Paruthi S, Brooks LJ, D’Ambrosio C, Hall WA, Kotagal S, Lloyd RM, et al. Recommended amount of sleep for pediatric populations: a consensus statement of the American Academy of Sleep Medicine. J Clin Sleep Med 2016;12(6):785-6. http://dx.doi.org/10.5664/jcsm.5866 PMid:27250809.
  » http://dx.doi.org/10.5664/jcsm.5866
• ⁶⁵
  Oliveira MM, Campos MO, Andreazzi MAR, Malta DC. Characteristics of the national adolescent school-based health survey - PeNSE, Brazil. Epidemiol Serv Saude 2017;26(3):605-16. http://dx.doi.org/10.5123/S1679-49742017000300017 PMid:28977184.
  » http://dx.doi.org/10.5123/S1679-49742017000300017
• ⁶⁶
  Carson V, Ezeugwu VE, Tamana SK, Chikuma J, Lefebvre DL, Azad MB, et al. Associations between meeting the Canadian 24-hour Movement Guidelines for the Early Years and behavioral and emotional problems among 3-year-olds. J Sci Med Sport 2019;22(7):797-802. http://dx.doi.org/10.1016/j.jsams.2019.01.003 PMid:30655179.
  » http://dx.doi.org/10.1016/j.jsams.2019.01.003
• ⁶⁷
  Cliff DP, McNeill J, Vella SA, Howard SJ, Santos R, Batterham M, et al. Adherence to 24-hour Movement Guidelines for the Early Years and associations with social-cognitive development among Australian preschool children. BMC Public Health 2017;17(Suppl. 5):857. http://dx.doi.org/10.1186/s12889-017-4858-7 PMid:29219104.
  » http://dx.doi.org/10.1186/s12889-017-4858-7
• ⁶⁸
  Kim Y, Umeda M, Lochbaum M, Stegemeier S. Physical activity, screen-based sedentary behavior, and sleep duration in adolescents: youth risk behavior survey, 2011–2013. Prev Chronic Dis 2016;13:E131. http://dx.doi.org/10.5888/pcd13.160245 PMid:27634781.
  » http://dx.doi.org/10.5888/pcd13.160245
• ⁶⁹
  Ying L, Zhu X, Haegele J, Wen Y. Movement in high school: proportion of Chinese adolescents meeting 24-hour movement guidelines. Int J Environ Res Public Health 2020;17(7):2395. http://dx.doi.org/10.3390/ijerph17072395 PMid:32244641.
  » http://dx.doi.org/10.3390/ijerph17072395
• ⁷⁰
  Chaput JP, Janssen I. Sleep duration estimates of Canadian children and adolescents. J Sleep Res 2016;25(5):541-8. http://dx.doi.org/10.1111/jsr.12410 PMid:27027988.
  » http://dx.doi.org/10.1111/jsr.12410
• ⁷¹
  Pearson N, Sherar LB, Hamer M. Prevalence and correlates of meeting sleep, screen-time, and physical activity guidelines among adolescents in the United Kingdom. JAMA Pediatr 2019;173(10):993-4. http://dx.doi.org/10.1001/jamapediatrics.2019.2822 PMid:31449287.
  » http://dx.doi.org/10.1001/jamapediatrics.2019.2822
• ⁷²
  Landmann-Szwarcwald C, Macinko J. A panorama of health inequalities in Brazil. Int J Equity Health 2016;15:174. http://dx.doi.org/10.1186/s12939-016-0462-1 PMid:27852273.
  » http://dx.doi.org/10.1186/s12939-016-0462-1
• ⁷³
  Brockmann PE, Gozal D, Villarroel L, Damiani F, Nuñez F, Cajochen C. Geographic latitude and sleep duration: a population-based survey from the tropic of Capricorn to the Antarctic circle. Chronobiol Int 2017;34(3):373-81. http://dx.doi.org/10.1080/07420528.2016.1277735 PMid:28128998.
  » http://dx.doi.org/10.1080/07420528.2016.1277735

Publication Dates

• Publication in this collection
  23 Aug 2021
• Date of issue
  2021

History

• Received
  23 Dec 2020
• Accepted
  05 July 2021