Abstract
Introduction: Associations between short sleep duration and increased BMI have been found in children and adults. However, it is unknown if short sleep-time during childhood has long-term consequences. We assessed the association between sleep-time in childhood and adult BMI in a prospective birth cohort.
Methods: Study members were a general population birth cohort of 1037 participants (502 female) born in Dunedin, New Zealand, between April 1972 and March 1973. Parental reports of bed and rising times collected at ages 5, 7, 9 and 11 years were used to estimate childhood sleep-time. Linear regression was used to analyse the association between childhood sleep-time and BMI measured at age 32 years.
Results: Lower childhood sleep-times were associated with higher adult BMIs (B=-0.99, 95%CI=-1.59 to -0.39, p=0.001). This association remained after adjusting for adult sleep-time and the potential confounding effects of early childhood BMI, childhood socioeconomic status, parental BMI, child and adult television viewing, adult physical activity and adult smoking (B=-0.93, 95%CI=-1.54 to -0.31, p=0.003. By logistic regression, more sleep-time during childhood was associated with a lower odds of obesity (OR=0.73, 95%CI=0.53 to 1.00, p=0.051) at age 32 years. This association was significant after adjusting for multiple potential confounding factors (OR =0.65, 95%CI=0.43 to 0.97, p=0.034).
Conclusions: These findings suggest that sleep restriction in childhood increases the long-term risk for obesity. Ensuring that children get adequate sleep may be a useful strategy for stemming the current obesity epidemic.