Sleep duration and physical fighting involvement in late adolescence

Abstract

Violence behaviours are among the leading causes of mortality and morbidity among young people worldwide, and evidence has shown changes in sleep patterns seem to affect school attainment, behaviour, emotion and attention control, and social interactions and relate with a more aggressive behaviour. We assessed the association between sleep duration and physical fighting involvement among 17-year-old Portuguese school-going adolescents. The analysis included 2426 Portuguese adolescents observed at wave 2 of the EPITeen cohort. Sleep duration was estimated by self-reported bed and wake-up times. Physical fighting involvement was based on the self-reported data regarding the year before the evaluation. Logistic regression models adjusted for potential confounders were used to calculate the odds ratio (OR) and 95% confidence intervals (95% CI). In our sample, 34.2% of participants had been involved in a physical fight at least once during the previous year. In girls, shorter sleep duration was significantly associated with physical fighting (OR = 1.35; 95% CI: 1.01; 1.81) and remained statistically significant after adjustment for parents’ education level (AOR = 1.36; 95% CI: 1.01; 1.83), although the association was attenuated after additional adjustment for tobacco use and depressive symptoms (AOR = 1.19; 95% CI: 0.86; 1.65). In boys, insufficient sleep was significantly associated with physical fighting (OR = 1.43; 95% CI: 1.12; 1.82) and remained statistically significant after adjustment for parents’ education level (AOR = 1.42; 95% CI: 1.11; 1.82) and after additional adjustment for tobacco use (AOR = 1.28; 95% CI: 1.00; 1.66). Shorter duration of sleep seems to be associated with physical fighting involvement, although the relationship might be mediated by other behavioural factors.