Is the use of high correlated color temperature light at night related to delay of sleep timing in university students? A cross-country study in Japan and China

Shigekazu Higuchi, Yandan Lin, Jingjing Qiu, Yichi Zhang, Michihiro Ohashi, Sang il Lee, Shingo Kitamura, Akira Yasukouchi

研究成果: Contribution to journalArticle査読

1 被引用数 (Scopus)

抄録

Background: Blue-enriched white light at night has the potential to delay the circadian rhythm in daily life. This study was conducted to determine whether the use of high correlated color temperature (CCT) light at home at night is associated with delay of sleep timing in university students. Methods: The survey was conducted in 2014–2015 in 447 university students in Japan and 327 students in China. Habitual sleep timing and type of CCT light at home were investigated by using a self-administered questionnaire. The Japanese students were significantly later than the Chinese students in bedtime, wake time, and midpoint of sleep. They were asked whether the lighting in the room where they spend most of their time at night was closer to warm color (low CCT) or daylight color (high CCT). The amount of light exposure level during daily life was measured for at least 1 week by the use of a light sensor in 60 students in each country. Results: The percentages of participants who used high CCT lighting at night were 61.6% for Japanese students and 80.8% for Chinese students. Bedtime and sleep onset time on school days and free days were significantly later in the high CCT group than in the low CCT group in Japan. The midpoint of sleep in the high CCT group was significantly later than that in the low CCT group on free days but not on school days. On the other hand, none of the sleep measurements on school days and free days were significantly different between the high CCT and low CCT groups in China. Illuminance level of light exposure during the night was significantly higher in Japanese than in Chinese, but that in the morning was significantly higher in China than in Japan. Conclusions: The use of high CCT light at night is associated with delay of sleep timing in Japanese university students but not in Chinese university students. The effects of light at night on sleep timing and circadian rhythm may be complicated by other lifestyle factors depending on the country.

本文言語英語
論文番号7
ジャーナルJournal of physiological anthropology
40
1
DOI
出版ステータス出版済み - 12 2021

All Science Journal Classification (ASJC) codes

  • 人的要因と人間工学
  • 生理学
  • 整形外科およびスポーツ医学
  • 人類学
  • 公衆衛生学、環境および労働衛生
  • 生理学(医学)

フィンガープリント

「Is the use of high correlated color temperature light at night related to delay of sleep timing in university students? A cross-country study in Japan and China」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

引用スタイル