The association between chronotype and sleep problems in preschool children

Area of Science:

• Developmental psychology
• Sleep science
• Chronobiology

Background:

• Evening-types in adolescents and adults report shorter sleep duration and more sleep issues.
• Chronotype, an individual's natural inclination towards morning or evening activity, is established early in life.

Purpose of the Study:

• To investigate the association between chronotype and sleep problems in preschool-aged children.
• To determine if evening-type preschoolers exhibit more sleep difficulties compared to their morning- or intermediate-type peers.

Main Methods:

• A subset of 4.5-year-olds from the 'Growing Up in Singapore Towards healthy Outcomes' birth cohort study participated.
• Children's Chronotype Questionnaire (CCTQ) classified participants into morning, intermediate, or evening types.
• Sleep problems were assessed using the Children's Sleep Habits Questionnaire (CSHQ).
• Actigraphy and sleep diaries were used in a subsample to analyze sleep-wake timing and duration.

Main Results:

• Evening-type preschoolers reported significantly more sleep problems (higher CSHQ scores) than morning- and intermediate-types, even after controlling for confounders.
• Actigraphy confirmed later bedtimes and wake times for evening-types on weekdays and weekends.
• Evening-types experienced shorter nocturnal sleep duration exclusively on weekdays.

Conclusions:

• Preschool children with an evening chronotype exhibit a greater prevalence of sleep problems.
• Chronotype appears to be a significant factor contributing to sleep disturbances in early childhood.
• These findings highlight the importance of considering chronotype in addressing sleep issues in young children.