Although engaging in evening naps and extracurricular activities are popular among Japanese high school students, the associations between these behaviors and daytime sleep problems were unclear. A questionnaire on daily life and sleeping habits was administered to 1314 high school students, aged between 15–17 years. The respondents were categorized by their after-school napping habits (did not nap, napped 1–2 days/week, napped ≥3 days/week), and their extracurricular activities (no activity, cultural club, athletic club). The mean nocturnal sleep duration on weekdays (± standard deviation (SD)) was 390 ± 56 min. This was significantly shorter in those students with a higher number of days/week spent napping (p < 0.001), and slightly longer for those in the athletic club (p < 0.001). Sleep problems—including subjective insufficient sleep, excessive sleepiness during class ≥3 days/week, and falling asleep during class ≥3 days/week—were reported by 64%, 55%, and 33% of respondents, respectively. A multiple logistic regression analysis showed significantly higher risks for excessive sleepiness among students taking naps ≥3 days/week, and who belonged to athletic clubs. In addition to those factors, students in cultural clubs revealed significantly higher risks for falling asleep during classes. Future studies are required to decrease daytime sleep problems associated with evening naps and extracurricular activities among high school students. (高校生では、学校からの帰宅後の仮眠および部活動参加の割合が高いが、これら行動要因と日中の睡眠問題との関連は明らかでない。そこで、ほぼ全員が大学に進学する高校の１・2年生計1314人を対象として、生活および睡眠習慣の質問紙調査を実施した。帰宅後の仮眠習慣は、週3日以上、週１-2日、無し、部活動は、運動部、文化部、無所属の群分けとした。全体の平日の睡眠時間は390 ± 56 分で、仮眠習慣が高頻度であるほど短く、運動部員でやや長かった。日中の睡眠問題は、睡眠不足、授業中の耐え難い眠気が週3日以上、授業中の居眠りが週3日以上とし、それぞれ、全体の64%, 55%, および33%が該当した。多変量ロジスティック解析により、授業中の耐え難い眠気が週3日以上のリスクは、帰宅後仮眠が週3日以上、および運動部員で高く、さらに深刻な状態である、授業中の居眠りが週3日以上は、これら二つの属性に加えて、文化部員でも高リスクであることが検出された。今後、これら睡眠問題を軽減する対策案の検討が望まれる。
1(3), 367-384; https://doi.org/10.3390/clockssleep1030030
Koh Mizuno, Kazue Okamoto-Mizuno, Kazuki Iwata
