title: Sleep Duration Trajectories and Body Composition in Adolescents: Prospective Birth Cohort Study.
abstract: We aimed to estimate the association between sleep duration trajectories and body composition in adolescents. We used data from participants of the 1993 Pelotas (Brazil) Birth Cohort Study who were later followed up at age 18 years (response rate of 81.3%). At the time, 3974 adolescents had complete data on body composition, which was assessed by air displacement plethysmography. Sleep duration was self-reported by participants at ages 11 and 18 years. Analyses were sex-stratified. The mean sleep duration at 11 years was 9.7 (SD 1.4) and 8.4 (SD 1.9) at 18 years. Sleep duration was dichotomized as inadequate (<8 hours/day) or adequate (≥8 hours/day). Mean body mass, fat mass, and fat-free mass indices at 18 years were 23.4 kg/m2 (SD 4.5), 6.1 kg/m2 (SD 3.9) and 17.3 kg/m2 (SD 2.5), respectively. Girls who reported inadequate sleep duration at 11 years of age, but adequate sleep duration at 18, on average experienced an increase in body mass index (β = 0.39 z-scores; 95% CI 0.13, 0.65), fat mass index (β = 0.30 z-scores; 95% CI 0.07, 0.53), and fat-free mass index (β = 0.24 z-scores; 95% CI 0.08, 0.39) compared to those who had adequate sleep duration at both time points. The results suggest that changes in sleep duration across adolescence may impact body composition in later adolescence and that this may differ by sex.
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Antônio Augusto
authors.initials: AA
authors.lastname: Schäfer
authors.affiliation: Post-Graduate Program in Physical Education, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Marlos Rodrigues
authors.initials: MR
authors.lastname: Domingues
authors.affiliation: Department of Epidemiology and Public Health, University College Cork, Cork, Ireland.
authors.forename: Darren Lawrence
authors.initials: DL
authors.lastname: Dahly
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Fernanda Oliveira
authors.initials: FO
authors.lastname: Meller
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Helen
authors.initials: H
authors.lastname: Gonçalves
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Fernando César
authors.initials: FC
authors.lastname: Wehrmeister
authors.affiliation: Post-Graduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Maria Cecília Formoso
authors.initials: MC
authors.lastname: Assunção
mesh_terms: D000293:Adolescent; D001823:Body Composition; D001938:Brazil; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012890:Sleep