Association between sleep duration and body mass index among US low-income preschoolers

Authors: VEZINA-IM, LYDI - Children'S Nutrition Research Center (CNRC); HUGHES, SHERYL - Children'S Nutrition Research Center (CNRC); BARANOWSKI, TOM - Children'S Nutrition Research Center (CNRC); NICKLAS, THERESA - Children'S Nutrition Research Center (CNRC)

Submitted to: Obesity
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/24/2017
Publication Date: 8/29/2017
Citation: Vezina-Im, L.A., Hughes, S.O., Baranowski, T., Nicklas, T.A. 2017. Association between sleep duration and body mass index among US low-income preschoolers. Obesity. doi:10.1002/oby.21963.

Interpretive Summary: Lack of sleep has been considered a risk factor for childhood obesity, however, most studies have not controlled for many possible factors which could otherwise explain away the relationship. This study was a secondary analysis of a study of evening meal dietary intakes among 228 African American or Hispanic preschoolers. Sleep duration was related to child adiposity even after controlling for child characteristics, but not after controlling for parent characteristics, including parent socioeconomic status, body mass index, stress and depression. The full model accounted for a very small percentage of the variance in child adiposity suggesting any detected relationships were weak. It does not appear that child sleep duration is related to child adiposity, at least among preschoolers.

Technical Abstract: Our objective was to verify whether sleep duration was related to body mass index z scores (zBMI) and whether bedtimes or ethnicity was a moderator of the sleep duration-zBMI association among preschoolers from low-income families. Two hundred twenty-eight African American and Hispanic parents and their preschoolers were recruited from Head Start Centers. Parents reported their preschoolers' sleep duration and bedtimes (using the Children's Sleep Habits Questionnaire) and their television watching. Food intake was measured using multiple days of digital photography to estimate energy intake at dinner. The Parenting Stress Index and the Center for Epidemiologic Studies Depression Scale were used to measure stress and depression. Parents' and preschoolers' height and weight were measured by trained staff. We found longer sleep duration was significantly associated with lower zBMI when controlling for demographics, bedtimes, energy intake at dinner, and television watching, but not when also controlling for parents' demographics, BMI, stress, and depression. Preschoolers' sleep duration-zBMI association was not moderated by bedtimes or ethnicity. We concluded longer sleep duration was associated with lower zBMI among low-income preschoolers when controlling for preschoolers' characteristics, but this was no longer the case when also controlling for parents' characteristics. Additional studies are needed on the moderators of the sleep duration-zBMI association among low-income preschoolers.