Associations between sleep duration, adiposity indicators, and cognitive development in young children

Area of Science:

• Pediatric Health
• Child Development
• Nutritional Science

Background:

• Childhood obesity is a growing concern, with adiposity indicators often established in early life.
• Sleep patterns in early childhood are complex and their impact on physical and cognitive development requires further investigation.

Purpose of the Study:

• To investigate the relationship between sleep duration (total, nap, and nighttime) and indicators of adiposity in young children.
• To examine the association between sleep duration and cognitive development, specifically expressive vocabulary and working memory, in preschoolers.

Main Methods:

• A cohort of 217 Canadian children aged 19-60 months (HATCH study) had sleep duration assessed via parent questionnaire.
• Adiposity was measured using Body Mass Index (BMI) z-scores and weight status based on WHO growth standards.
• Cognitive functions (expressive vocabulary, working memory) were evaluated in preschoolers (36-60 months) using the Early Years Toolbox, with statistical analyses employing mixed models.

Main Results:

• A negative linear association was found between total sleep duration and BMI z-score.
• Children with shorter nighttime sleep (<9.13-11.13 h/d) exhibited higher BMI z-scores and increased odds of being overweight.
• No significant associations were observed between sleep duration and expressive vocabulary; however, non-nappers showed greater working memory capacity compared to nappers.

Conclusions:

• Ensuring adequate total sleep, particularly exceeding nine hours of nighttime sleep, is crucial for maintaining healthy adiposity in young children.
• Discontinuing napping may correlate with enhanced working memory performance in preschool-aged children.