Tim S Olds1, Carol A Maher, Lisa Matricciani. 1. Health and Use of Time (HUT) Group, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia.
Abstract
STUDY OBJECTIVES: To assess the effects of early and late bedtimes and wake up times on use of time and weight status in Australian school-aged children. DESIGN: Observational cross-sectional study involving use of time interviews and pedometers. SETTING: Free-living Australian adolescents. PARTICIPANTS: 2200 9- to 16-year-olds from all states of Australia INTERVENTIONS: NA. MEASUREMENTS AND RESULTS: Bedtimes and wake times were adjusted for age and sex and classified as early or late using median splits. Adolescents were allocated into 4 sleep-wake pattern groups: Early-bed/Early-rise; Early-bed/Late-rise; Late-bed/Early-rise; Late-bed/Late-rise. The groups were compared for use of time (screen time, physical activity, and study-related time), sociodemographic characteristics, and weight status. Adolescents in the Late-bed/Late-rise category experienced 48 min/d more screen time and 27 min less moderate-to-vigorous physical activity (MVPA) (P<0.0001) than adolescents in the Early-bed/Early-rise category, in spite of similar sleep durations. Late-bed/Late-rise adolescents had a higher BMI z-score (0.66 vs. 0.45, P=0.0015). Late-bed/Late-rise adolescents were 1.47 times more likely to be overweight or obese than Early-bed/Early-rise adolescents, 2.16 times more likely to be obese, 1.77 times more likely to have low MVPA, and 2.92 times more likely to have high screen time. Late-bed/Late-rise adolescents were more likely to come from poorer households, to live in major cities, and have fewer siblings. CONCLUSIONS: Late bedtimes and late wake up times are associated with an unfavorable activity and weight status profile, independent of age, sex, household income, geographical remoteness, and sleep duration.
STUDY OBJECTIVES: To assess the effects of early and late bedtimes and wake up times on use of time and weight status in Australian school-aged children. DESIGN: Observational cross-sectional study involving use of time interviews and pedometers. SETTING: Free-living Australian adolescents. PARTICIPANTS: 2200 9- to 16-year-olds from all states of Australia INTERVENTIONS: NA. MEASUREMENTS AND RESULTS: Bedtimes and wake times were adjusted for age and sex and classified as early or late using median splits. Adolescents were allocated into 4 sleep-wake pattern groups: Early-bed/Early-rise; Early-bed/Late-rise; Late-bed/Early-rise; Late-bed/Late-rise. The groups were compared for use of time (screen time, physical activity, and study-related time), sociodemographic characteristics, and weight status. Adolescents in the Late-bed/Late-rise category experienced 48 min/d more screen time and 27 min less moderate-to-vigorous physical activity (MVPA) (P<0.0001) than adolescents in the Early-bed/Early-rise category, in spite of similar sleep durations. Late-bed/Late-rise adolescents had a higher BMI z-score (0.66 vs. 0.45, P=0.0015). Late-bed/Late-rise adolescents were 1.47 times more likely to be overweight or obese than Early-bed/Early-rise adolescents, 2.16 times more likely to be obese, 1.77 times more likely to have low MVPA, and 2.92 times more likely to have high screen time. Late-bed/Late-rise adolescents were more likely to come from poorer households, to live in major cities, and have fewer siblings. CONCLUSIONS: Late bedtimes and late wake up times are associated with an unfavorable activity and weight status profile, independent of age, sex, household income, geographical remoteness, and sleep duration.
Entities:
Keywords:
Child; bedtime; physical activity; screen time; wake up time
Authors: S M Martinez; J M Tschann; C E McCulloch; E Sites; N F Butte; S E Gregorich; C Penilla; E Flores; L A Pasch; L C Greenspan; J Deardorff Journal: Sleep Health Date: 2018-12-12
Authors: R Glenn Weaver; Michael W Beets; Michelle Perry; Ethan Hunt; Keith Brazendale; Lindsay Decker; Gabrielle Turner-McGrievy; Russell Pate; Shawn D Youngstedt; Brian E Saelens; Alberto Maydeu-Olivares Journal: Sleep Date: 2019-01-01 Impact factor: 5.849