Association between exposure to light at night and ambulatory 24-hour blood pressure among college students

This study aims to explore the association between exposure to light at night (LAN) and ambulatory blood pressure (BP) profiles in college students. A school-based cross-sectional study was conducted in a university of Changsha, Hunan Province, China. We recruited 732 college students from September 2023 to June 2024. Abnormal BP phenotypes include abnormal daytime/nighttime/24 h/ambulatory BP. Abnormal ambulatory BP is defined by presence of abnormal daytime/nighttime/24 h BP. After exclusion, a total of 688 participants were included in the final analysis with an age of 19 years (IQR 18, 20), with 501 (72.8%) females. After adjustment of potential covariates, including age, sex, body mass index, chronotype, sedentary behavior, physical activity, and intake of fruits and vegetables, participants with LAN exposure had a significantly higher risk of abnormal daytime BP (OR = 5.12, 95%CI, 1.30–20.14), abnormal nighttime BP (OR = 2.61, 95%CI, 1.00–6.77), abnormal ambulatory BP (OR = 3.80, 95%CI, 1.55–9.30) and abnormal daytime SBP (OR = 4.28, 95%CI, 1.08–16.98), than the non-LAN exposure group. When the LAN exposure was categorized as high, moderate/low and non-exposure, similar results were obtained, especially for abnormal nighttime SBP. Light pollution at night is associated with abnormal ambulatory BP profiles among young adults, especially for abnormal nighttime SBP.