# The mediating role of sleep disorders in the relationship between breastfeeding and behavioral problems among 6- to 8-year-old children in Shanghai, China

## TL;DR

This study explores how sleep disorders might explain the link between breastfeeding and behavioral problems in young children.

## Contribution

It identifies sleep disorders as potential mediators in the relationship between breastfeeding and childhood behavioral problems.

## Key findings

- Breastfeeding was associated with higher sleep problem scores and specific sleep issues.
- Breastfeeding had direct and indirect effects on multiple behavioral domains, including learning problems and hyperactivity.
- Sleep disorders may mediate the relationship between lack of breastfeeding and behavioral problems in children.

## Abstract

Improving breastfeeding rates is a key target in the WHO Global Nutrition Targets 2025, yet the link between breastfeeding duration/exclusivity and childhood behavioral problems (BPs) remains controversial due to conflicting evidence. This study examined the role of sleep disorders in mediating the relationship between breastfeeding and BPs in children. Its aim was to provide a scientific basis for early intervention in children with BPs.

This cross-sectional study was conducted across 34 elementary schools in Xuhui District, Shanghai, China, between September and December 2019. The valid data were collected from 11,319 primary school students aged 6–8 years. An online survey completed by their guardians was used to obtain demographic information and to score the Children's Sleep Habits Questionnaire (CSHQ) and Conners' Parent Rating Scale (CPRS). Descriptive statistics (frequencies and medians) were generated. Associations among variables were assessed using the Mann–Whitney U test, Spearman's rank correlation, and a path analysis (incorporating a bootstrap analysis to assess direct and indirect effects). CPRS scores were converted to z-scores using sex- and age-specific means and sleep disorders, with a z-score > 2 indicating abnormal behavior.

In our sample, the breastfeeding rate was 64.55% (n = 7,306/11,319). Controlling for age, gender, BMI z-score, parental age/education, breastfeeding was linked to higher overall sleep problem scores (CSHQ) and specific issues including bedtime resistance, sleep anxiety, and sleep-disordered breathing (all p < 0.05). At the same time, the results show that both breastfeeding and the 8 items of the CSHQ have direct and significant effects on the Learning problems, Impulsive—hyperactive, and Hyperactivity (all p < 0.05). Breastfeeding demonstrated significant total effects on multiple behavioral domains: conduct problems (β = 0.044, p = 0.025, indirect effect β = 0.030), Learning problems (β = 0.089, p < 0.001; direct β = 0.059, indirect β = 0.030), Psychosomatic problems (β = 0.072, p < 0.001; direct β = 0.048, indirect β = 0.024), Impulsive-hyperactive behaviors (β = 0.074, p < 0.001; direct β = 0.046, indirect β = 0.028), Anxiety (fully mediated, β = 0.054, p < 0.01, indirect β = 0.027), and Hyperactivity (β = 0.068, p < 0.01; direct β = 0.035, indirect β = 0.032). All 95% CIs for indirect effects excluded zero.

Sleep disorders may mediate the relationship between the lack of breastfeeding and BPs in children 6–8 years of age, though our cross-sectional design precludes causal inference and parent-reported sleep disorders severity may bias true associations. Future studies should utilize longitudinal cohorts to explore whether sleep disorders is involved in the relationship between breastfeeding and behavioral problems.