The mediating role of sleep bedtime regularity in the association between neighborhood factors and childhood obesity

Background: Regular bedtime patterns have been inversely associated with obesity. In turn, safe and supportive neighborhoods positively associate with children's bedtime regularity. We sought to determine whether bedtime regularity mediates between these two neighborhood factors and obesity among US children aged 6–17. Methods: Using data from the 2021-22 National Survey of Children's Health (n = 59,078), two mediation models tested the effect of bedtime regularity on associations between neighborhood factors and obesity. Both models adjusted for sex, age, race/ethnicity, household poverty, physical activity, and caregiver's education. Caregivers reported on neighborhood factors, obesity, and sleep. Results: Unsafe neighborhoods: In Model 1, living in unsafe neighborhoods associated with irregular bedtime (OR = 1.82 [95 % CI: 1.46, 2.28]). In Model 2, living in unsafe neighborhoods did not significantly associate with obesity (OR = 1.12 [0.89, 1.40]); irregular bedtime significantly associated with obesity (OR = 1.22 [1.07, 1.40]). Bootstrap CIs derived from 1000 samples indicated a significant indirect mediating effect (adjusted β = 0.02 [0.01, 0.022]). Unsupportive neighborhoods: In Model 1, living in unsupported neighborhoods associated with irregular bedtime (OR = 1.58 [1.41, 1.76]). In Model 2, living in unsupported neighborhoods and irregular bedtime significantly associated with obesity (OR = 1.14 [1.03, 1.26] and 1.21 [1.06, 1.39]). Bootstrap CIs indicated a significant indirect mediating effect (adjusted β = 0.01 [0.007, 0.014]). Conclusions: Our findings highlight the impact of living in disadvantaged neighborhoods and suggest promoting bedtime regularity may be a suitable obesity intervention target for youth living in these settings. Due to the small effect sizes and the cross-sectional design of our study, our findings should be considered along with other established targets.