Associations of Infant Sleep Duration with Body Composition and Cardiovascular Health to Mid-Adolescence: The PEAS Kids Growth Study

Abstract
Background: Short sleep duration in childhood has often been linked with obesity in later childhood or adolescence. However, whether infant sleep duration affects body composition trajectories and cardiovascular health through to mid-adolescence remains unknown.
Methods: Participants were 336 adolescents from a community-based prospective birth cohort in Melbourne, Australia. Mothers completed 24-hour time diaries, including infant sleep in 5-minute intervals at ages 2, 4, and 12 months. BMI and body composition outcomes were measured 6-monthly between 4 and 6.5 years and at 10 and 14 years. Cardiovascular outcomes at 14 years comprised blood pressure, pulse wave velocity, retinal arteriole-to-venule ratio, and carotid intima-media thickness. We used multivariable linear regression and multinomial logistic regression analyses adjusted for sex, age, BMI at birth, gestational age, ethnicity, maternal education, maternal BMI, and neighborhood socioeconomic position.
Results: At 2 months, infants slept on average 14.1 hours [standard deviation (SD) 1.9], decreasing to 13.4 hours (SD 2.0) by 12 months. We observed no associations between the different sleep duration time points in infancy and later BMI or body composition. Moreover, a shorter sleep duration did not increase the odds of being on a high body composition trajectory compared with longer sleep (e.g., odds ratio per hour of sleep at 4 months is 0.85, 95% confidence interval 0.65–1.11). Infant sleep duration was also not associated with cardiovascular function or large or small artery structure at 14 years of age.
Conclusions: We found no evidence that sleep duration very early in life affects adolescent body composition or cardiovascular health.