Abstract
Context: Associations between short sleep duration and increased body mass index 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 body mass index in a birth cohort.
Methods: Study members were a general population birth cohort of 1037 participants (502 female) were 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 body mass index measured at age 32 years.
Results: Lower childhood sleep-times were significantly associated with higher adult body mass indices (regression coefficient = -0.99, 95% confidence interval = -1.59 to -0.39, p = 0.001). This association remained after adjustment for adult sleep-time and the potential confounding effects of early childhood body mass index, childhood socioeconomic status, parental body mass indices, child and adult television viewing, adult physical activity and adult smoking (coefficient = -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.