Infant sleep problems and childhood overweight: Effects of three definitions of sleep problems

Sleep problems have been defined using a variety of definitions. No study has assessed the longitudinal association between infant sleep problems and childhood overweight or obesity using existing definitions of sleep problems. This study used longitudinal data (n = 895) from the multi-site Study of Early Child Care and Youth Development (SECCYD) to investigate the effects of infant sleep problems on childhood weight status in Grade 6. Infants with sleep problems in Phase I (1991) and with complete data through Phase III (2004) of SECCYD were included. Sleep problems were assessed using maternal reports of night wakings and duration of a waking episode. Sleep problems were defined using Richman (1981), Lozoff et al. (1985), and Zuckerman et al. (1987) definitions. Multinomial logistic regression was used to examine the association between sleep problems during infancy and childhood weight status in Grade 6 while controlling for birth weight, race, sex, breastfeeding, maternal poverty, family structure, and maternal education. After adjusting for all covariates, children with a history of sleep problems were found to be overweight in Grade 6 using Zukerman et al. (Odds ratio (OR) = 1.68; 95% confidence interval (CI): 1.11–2.55) and Richman (OR = 1.76; 95% CI: 1.05–2.97) definitions, but not using Lozoff et al. definition. Infant sleep problems were not found to be associated with being obese. The study found differential effects of infant sleep problems on childhood overweight in Grade 6 per different definitions of sleep problems. Findings highlight the need to construct a single definition of infant sleep problems.