Emergence of racial/ethnic differences in infant sleep duration in the first six months of life

Abstract Objective Examine the emergence of differences in sleep duration between infants from different racial/ethnic backgrounds and extent to which differences are explained by socioeconomic status (SES) and sleep continuity. Methods Sleep duration and continuity (number of night wakings and longest nighttime stretch of sleep) were assessed for 394 infants in the Rise & Sleep Health in Infancy & Early Childhood (SHINE) birth cohort at one- and six-months using the Brief Infant Sleep Questionnaire (BISQ). Multivariable regression was used to estimate associations of race/ethnicity with sleep duration adjusting for individual-level covariates, SES, and sleep continuity. Results The sample was 40% non-Hispanic white, 33% Hispanic, 11% Black, and 15% Asian. Mean (SD) durations for daytime, nighttime, and total sleep at one-month were 6.3 (2.0), 8.9 (1.5), and 15.2 (2.7) hours, respectively. Corresponding durations at six-months were 3.0 (1.4), 9.9 (1.3), and 13.0 (1.9) hours. At one-month, Hispanic infants had shorter nighttime sleep than white infants [β: −0.44 h (95% CI: −0.80, −0.08)]. At six-months, Hispanic [β: −0.96 h (−1.28, −0.63)] and Black [β: −0.60 h (−1.07, −0.12)] infants had shorter nighttime sleep than white infants. The near 1-h differential in night sleep among Hispanics resulted in shorter total sleep [β: −0.66 h (−1.16, −0.15)]. Associations across all racial/ethnic groups were attenuated after adjustment for SES at one- and six months. Sleep continuity attenuated associations with nighttime and total sleep duration by 20–60% for Hispanic infants at six-months. Conclusions Differences in sleep duration emerge early in life among racial/ethnic groups and are in part explained by SES and sleep continuity.