Multiple trajectories of life style indicators and their links to myopia in the middle school students: A five-year cohort study

Little is known about the epidemiology of myopia-related behavior patterns among adolescents in economically developed regions of China, and their associations with myopia.This prospective cohort study included 1945 adolescents aged 12 to 17 years from 2019 to 2023. Lifestyle indicators (sleep time, moderate to vigorous physical activity (MVPA), outdoor time, screen time, extra-study time) were investigated by self-reported questionnaire annually, and trajectory groups were generated using group-based multi-trajectory models. The main outcome measures were noncycloplegic refractions and axial length (AL), corneal radius (CR).In the cohort of‌ 1945 participants, we identified three lifestyle trajectory groups based on the distribution of lifestyle indicators. The "General" group accounted for 38.2%, exhibiting a longer sleep duration of about 8 h, approximately 3 days of MVPA ≥ 1 h weekly, daily outdoor time of at least 2 h, around 2 h of daily screen time, and weekly extra-study time of 0.5 h. The "Rapidly declining sleep time and prolonged extra-study time" (52.2%) group was characterized by a rapidly declining sleep duration and 2.5 h of weekly extra-study time. The "Persistently low MVPA and prolonged extra-study time" group (8.8%) demonstrated minimal physical activity, averaging only 0.6 days of MVPA ≥ 1 h weekly and 2 h of weekly extra-study time. Compared to "General", the "Rapidly declining sleep time and prolonged extra-study time" lifestyle was associated with myopia(OR:1.30; 95%CI = 1.01 to 1.67), rapid SE progression(OR = 1.35; 95%CI = 1.06 to 1.72), and higher myopia degree(OR = 1.10; 95%CI = 1.01 to 1.20); longer AL(β coefficient: 0.17; 95%CI = 0.05 to 0.29) and positive AL/CR ratio(β coefficient: 0.02; 95%CI = 0.01 to 0.03), but not associated with AL progression or AL/CR ratio progression. For middle school students in China, there were 3 different patterns of myopia-related behaviors. The lifestyle characterized by prolonged extra-study time and rapidly declining sleep time was associated with an elevated risk for myopia.