School start time influences melatonin and cortisol levels in children and adolescents - a community-based study.

School start time influences sleep parameters. Differences between circadian sleep parameters on weekends and weekdays have been associated with obesity, sleep, and psychiatric disorders. Moreover, circadian rhythm dysregulation affects the secretion of some hormones, such as melatonin and cortisol.

The influence of school time on sleep patterns of children and adolescents.

Objective: This epidemiological study evaluated the impact of school time on sleep parameters of children and adolescents.

Methods: This cross-sectional study involved 639 elementary and high school students (mean age 13.03 years, range 8-18, 58.