Abstract
Objectives: To determine whether sleep patterns (duration, timing, efficiency) differ by ethnicity.
Design: Longitudinal study.
Setting: Dunedin, New Zealand.
Participants: A total of 939 children (48% male) aged 4-12 years (572 European, 181 Māori, 111 Pacific, 75 Asian).
Measurements: All measurements were obtained at months 0, 12, and 24. Anthropometry was obtained using standard techniques, and parents completed questionnaires assessing demographics, dietary intake, and television habits of children. Sleep and physical activity were measured using Actigraph accelerometers over 1 week. Differences in sleep outcomes according to ethnicity were adjusted for demographics, weight status, and behavioral variables using mixed models.
Results: Pacific children had greater body mass index and were more likely to live in deprived areas than children from other ethnic groups (all P<.001), but few differences were observed in behavioral variables. Pacific Island children slept 16 (95% confidence interval, 7-25) minutes less per night than New Zealand European children, predominantly as a result of later bedtimes (29; 20-38 minutes). By contrast, sleep efficiency did not differ by ethnicity or over time (all P≥.118). Māori children did not show the same relative deficits in sleep, displaying similar results to European children. Sleep duration decreased by 8 minutes (95% confidence interval, 6-10) a night each year over 2 years, and change over time did not differ by ethnicity (all P≥.165).
Conclusions: From a young age, Pacific children had poorer sleep patterns than European children, and these patterns were maintained over 2 years.