Objective To explore the relationship between chronotype preference (morningness-eveningness) and sleep quality among Chinese adolescents.
Methods The data of the study were from National Youth Mental Health Survey conducted by Institute of Psychology of Chinese Academy of Sciences in 2009 in six provinces across China. In the survey, 3 944 sixth grade elementary school students and high school students with a mean age of 15.06 ± 2.49 years and approximately 1 : 1 gender ratio were selected using stratified multistage cluster random sampling and surveyed with Morningness/ Eveningness Scale for Children (MECS), Pittsburgh Sleep Quality Index (PSQI) and The Center for Epidemiological Studies Depression Scale (CES-D).
Results There was a significant gender difference in MESC score ( t = 2.89, P < 0.01). The MESC score was 32.02 ± 4.61, 29.65 ± 4.21, and 29.13 ± 4.08 for the students aged 10 – 13, 14 – 17, and 18 – 22 years, with a significant difference ( P < 0.01).The adolescents with eveningness preference (evening-type) had significantly higher both global PSQI score (6.64 ± 2.68 vs. 3.96 ± 2.40) and seven PSQI component scores than those with morningness preference (morning-type) (all P < 0.05). The evening-type adolescents went to bed later than morning-type adolescents on both school days and weekends ( P < 0.05) and they also tended to get up later than morning-type adolescents on weekend ( P < 0.05）; the evening-type adolescents had shorter sleep time on school days than morning-type students ( P < 0.05). There was no significant difference between evening-type and morning-type adolescents in the weekday wake-up time and weekend sleep time. Hierarchical regression analysis showed that among the adolescents, depression partially mediated the relationship between chronotype preference and sleep quality, with a mediated effect value of 0.13 and the ratio of mediated effect to total effect was 39.6%.
Conclusion Evening-type adolescents have higher PSQI scores, worse sleep quality and suffer more from inadequate sleep in school days; chronotype preference has both direct and indirect effect via depression on sleep quality among adolescents.
【摘 要】 目的 分析中国青少年昼夜偏好类型及其与睡眠质量问题的关系。 方法 采用中国科学院心理研究所全国青少年心理健康数据库中 2009 年调查数据，该调查采用多阶段分层整群随机抽样方法在浙江、福建、河南、湖北、辽宁、甘肃 6 个省抽取小学六年级至高中三年级在校学生 3 944 人进行昼夜偏好量表（MESC）和匹兹堡睡眠质量指数量表（PSQI）以及流调中心抑郁量表（CES-D）简版问卷调查。 结果 昼夜偏好得分在男、女生中差异有统计学意义（ t = 2.89， P < 0.01）。青少年早期（10 ～ 13 岁）、中期（14 ～ 17 岁）、晚期（18 ～ 22 岁）3 个年龄组昼夜偏好得分分别为（32.02 ± 4.61）、（29.65 ± 4.21）、（29.13 ± 4.08）分，差异有统计学意义（ P < 0.01）。在睡眠质量 PSQI 总分上，夜晚型偏好青少年得分为（6.64 ± 2.68）分，高于清晨型青少年的（3.96 ± 2.40）分；在睡眠质量 7 个因子分得分上，夜晚型偏好青少年得分均高于清晨型青少年,且差异均有统计学意义（均 P < 0.05）。夜晚型偏好青少年的上学日上床时间、周末上床时间和周末起床时间平均值均晚于清晨型偏好青少年，上学日睡眠时长短于清晨型偏好青少年，差异均有统计学意义（均 P < 0.05）。在上学日起床时间和周末睡眠时长方面，夜晚型偏好和清晨型偏好青少年组间差异无统计学意义。分层回归显示，青少年抑郁情绪在昼夜偏好与睡眠质量之间起部分中介作用，中介效应为 0.13，中介效应占总效应比例为 39.6 %。 结论 夜晚型偏好青少年 PSQI 睡眠质量得分更高，睡眠质量更差,在上学日睡眠不足情况更为严重；昼夜偏好既对睡眠质量产生直接影响，又通过青少年抑郁情绪间接影响睡眠质量。