Tohoku J. Exp. Med., 2009, 219(2)

Irregular Sleep Habits of Parents Are Associated with Increased Sleep Problems and Daytime Sleepiness of Children

YOKO KOMADA,¹ NAOMI ADACHI,² NORIKO MATSUURA,² KOH MIZUNO,³ KAZUHIRO HIROSE,⁴ RYOJI ARITOMI² and SHUICHIRO SHIRAKAWA⁵

¹Department of Somnology, Tokyo Medical University, Tokyo, Japan
²S&A Associates, Inc., Tokyo, Japan
³Faculty of Child and Family Studies, Tohoku Fukushi University, Miyagi, Japan
⁴Department of Obstetrics and Gynecology, Chibanishi General Hospital, Chiba, Japan
⁵National Institute of Mental Health, National Center of Neurology and Psychiatry, Tokyo, Japan

Longitudinal studies in Japan indicate that nocturnal sleep onset has become later and sleep duration has been progressively shortened. This study aimed to investigate the relationship between sleep patterns and sleep problems among children, and to determine the association between parents and their children's sleep habits. Questionnaires about sleep problems and life habits were administered to families living in Tokyo metropolitan areas of Japan. We analyzed the data of pre-school-age (1-5 years old; n = 319, including 175 girls) and elementary school-age children (6-11 years; n = 217, including 116 girls) as well as their parents (402 mothers: 37.0 ± 4.9 years, 402 fathers: 39.0 ± 5.9 years). Subjects were categorized as morning (evening) type when they answered their lifestyle habit as “definitely or moderately morning (evening) type”. Sleep was categorized into regular, irregular, and intermediate from the sleeping-waking regularity scores. The frequency of daytime dozing is significantly high in children with evening-irregular sleep. Moreover, mothers of children (aged 1-5 and 6-11 years) with evening-irregular sleep have significantly more irregular sleep habits than those of children with morning-regular sleep. Likewise, fathers of children (aged 1-5 years) with evening-irregular sleep have significantly more irregular sleep habits. Thus, irregular late bedtime of parents is associated with sleep problems, daytime sleepiness, and irregular dietary habits of children. Mothers' sleep habits have a stronger influence on their children's sleep than fathers'. Our study indicates the importance of promoting sleep hygiene that encourages healthy sleep for all family members.

keywords —— sleep hygiene; irregular sleep schedule; parent; limit setting; children.

© 2009 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2009, 219, 85-89

Correspondence: Yoko Komada, Department of Somnology, Tokyo Medical University, 6-7-1 Nishishinjuku, Shinjuku-ku, Tokyo, 160-0023, Japan.

e-mail: ykoma@tokyo-med.ac.jp