Abstract
Introduction: Disturbed sleep patterns are commonly reported among young adult university students, but limited evidence exists in community populations. This potentially introduces bias in our understanding of sleep patterns in early adulthood. We addressed this by characterising chronotype and sleep-corrected social jetlag (SJLsc) in a large, representative community population of 22-year-old adults and examined associations with quality of life (QoL).
Method: 867 participants (52% male, 22 years) from the Raine Study in Australia completed the morningness-eveningness questionnaire (MEQ) and self-reported bed and wake times on work and non-workdays. Linear regressions adjusted for sex and self-reported count of comorbidities were used to examine the association between chronotype and SJLsc (absolute difference between the sleep onset on free days and workdays; dichotomised by the median value) separately for physical and mental health sub-components of QoL according to the Short Form Survey (SF 12).
Results: Morning, intermediate and evening chronotypes were reported by 27%, 58% and 14% of the sample, respectively. Participants had a median SJLsc of 1 h (interquartile range, 0.5–2 h). In adjusted models, relative to morning chronotypes, evening chronotypes on average scored 2.7 units lower on physical (95% CI −4.0, −1.3; p < 0.001) and 4.8 units lower on mental health QoL (95% CI −6.9, −2.6; p < 0.001) sub-scales. There was no evidence of a meaningful association between SJL and QoL.
Conclusion: In young adults, evening chronotype is associated with poorer physical and mental components of QoL. These findings were not related to presence of SJL. Education and interventions to support the quality of life of evening chronotypes during early adulthood are likely needed.