Association between short time in bed, health-risk behaviors and poor academic achievement among Norwegian...

To investigate the prevalence of short time in bed (<8h/day) and to examine the association between time in bed, overweight/obesity, health-risk behaviors and academic achievement in adolescents.

This study included a sample of adolescents (n=2432) aged 15-17 years in the southern part of Norway (participation rate, 98.7%). A self-report questionnaire was used to assess time in bed, body mass index, dietary habits, physical activity habits, sedentary behavior, smoking and snuffing habits, and academic achievement.

A total of 32.3% of the students reported short time in bed (<8h/day) on an average school night. Several health-risk behaviors were associated with short sleep duration, including not being physically active for > or =60 min for > or =5 days/week (adjusted odds ratio, 1.33; 95% confidence interval, 1.05-1.68); using television/computer >2 h/day (1.63; 1.23-2.17); being a current smoker (2.46; 1.80-3.35) or snuffer (2.11; 1.57-2.85); having an irregular meal pattern (1.33; 1.05-1.68); intake of sweets/candy > or =4 times/week (0.51; 0.32-0.83); and poor academic achievement (1.62; 1.26-2.09). All odds ratios were adjusted for sex, age and parental education.

In Norwegian adolescents, short time in bed is associated with several health-risk behaviors and poor academic achievement.