Lifestyle factors associated with premenstrual syndrome: a cross-sectional study of Japanese high school students.

To investigate the relationships between premenstrual syndrome (PMS) and lifestyle, sleep, and dietary habits among Japanese high school students DESIGN: Cross-sectional study; SETTING: Two public high schools in Sendai, the largest city in northeastern Japan PARTICIPANTS: A school-based survey was conducted among 1818 female Japanese high school students in 2015, and 1022 students with regular menstrual cycles (25-38 days) completed the questionnaire.Relationships between PMS and lifestyle, sleep, and dietary habits RESULTS: The rates of moderate-to-severe PMS and premenstrual dysphoric disorder were 9.7% and 2.2%, respectively. A total of 121 students (11.9%) were classified as having PMS-the PMS(+) group. Significant differences were observed between the PMS(+) and PMS(-) groups in age at menarche (p = 0.022), menstrual pain (p < 0.001), hypnagogic disorder (p < 0.001), long Internet use time (p < 0.001), eating breakfast (p = 0.018), chewing well (p = 0.037), and belonging to a sports club (p = 0.046). Multivariate analysis revealed that the risk factors for PMS were menstrual pain (odds ratio [OR] = 4.74, 95% confidence interval [CI]: 2.83-7.95), hypnagogic disorder (OR = 2.22, 95% CI: 1.47-3.35), stress fracture (OR = 2.19, 95% CI: 1.21-3.98), and Internet use time (OR = 1.003, 95% CI: 1.001-1.005). Belonging to a sports club decreased the risk of PMS (OR = 0.57, 95% CI: 0.35-0.91).Sleep, dietary habits, belonging to a sports club, and screen time affect PMS among high school students.