Low sleep and low socioeconomic status predict high body mass index: a 4-year longitudinal study of Australian schoolchildren

• Published in: Pediatric obesity 2012-08, Vol.7 (4), p.295-303
• Main Authors: O'Dea, J. A., Dibley, M. J., Rankin, N. M.
• Format: Article
• Language: English
• Subjects: Adolescent; Age Factors; Analysis of Variance; Body Mass Index; Body mass index (BMI); Chi-Square Distribution; Child; Female; Humans; Linear Models; Longitudinal Studies; Male; Motor Activity; New South Wales - epidemiology; obesity; Obesity - epidemiology; Obesity - physiopathology; Overweight - epidemiology; Overweight - physiopathology; Risk Assessment; Risk Factors; Sleep; Socioeconomic Factors; Surveys and Questionnaires; Time Factors
• ISSN: 2047-6302; 2047-6310
• DOI: 10.1111/j.2047-6310.2012.00054.x

Summary Objective The objective of this study was to examine the longitudinal relationships between body mass index (BMI), sleep duration and socioeconomic status (SES) in a 4‐year cohort of 939 children aged 7–12 years. Methods Children and their mothers completed an annual questionnaire to assess usual weekday sleep and wake times, amount of sleep, physical activity, parental education and school SES. 93% of children were enrolled (939/1010) and retention was 88%, 83% and 81% in consecutive years. Height and weight were measured annually. Results BMI increased with decreasing amount of sleep and less sleep predicted greater International Obesity Task Force measures of obesity and overweight. In all 4 years, after controlling for baseline BMI, low SES was a significant predictor of high BMI. Children in the upper tertile of sleep in year 1 had a 2.3 kg lower weight gain (standard error [SE]: 0.5) between years 1 and 4 (P