Objective: To examine the association between secondhand smoke (SHS) exposure in indoor public places and sleep deprivation, so as to provide a reference for strengthening the management of a smoking ban in public places and to promote better sleep in childhood. Methods: Data were obtained from the second follow up survey of the Huantai Childhood Cardiovascular Health Cohort Study, which was conducted from November to December 2021. A total of 1 284 children aged 10-15 years old were included in the study. The participants were assigned to four groups (0, 1-2, 3-4 and ≥5 days) according to the frequency which they were exposed to SHS in indoor public places in the previous 7 days. Multiple linear regression was performed to examine the trend of children s sleep duration with the frequency of SHS exposure. Multivariate Logistic regression was carried out to determine the association between frequency of SHS and sleep deprivation. Results: After adjusting for age, sex, grade, physical activity, intake of fruits/vegetables, intake of soft drinks, screen duration, body mass index (BMI) and blood pressure, the average sleep duration of children who were exposed to SHS for 0, 1-2, 3-4 and ≥5 days in the previous 7 days was 8.48, 8.41, 8.20 and 8.06 h/d , respectively, and the average sleep duration decreased with exposure frequency of SHS ( t=5.96, 5.89, 5.91, P < 0.01 ). The proportion of sleep deprivation among children who were exposed to SHS in public places for 0, 1-2, 3-4 and ≥5 days in the previous 7 days was 40.02%, 43.07%, 54.65% and 63.41%, respectively. Compared to children who were not exposed to SHS in indoor public places in the past 7 days, those exposed for 3-4 days ( OR=1.93, 95%CI =1.19-3.15) or ≥ 5 days ( OR=2.95, 95%CI = 1.76- 4.94) had a significantly increased risk of sleep deprivation ( P <0.05). Conclusion Children s sleep time decreases with increasing frequency of exposure to SHS, and children who are frequently exposed to SHS are more likely to experience insufficient sleep. Smoking ban management in public places should be strengthened to promote children s sleep health, especially indoor public places.

Objective: To examine the association between secondhand smoke exposure (SHS) in indoor public places and carotid intima media thickness (cIMT) in children and adolescents, so as to provide guidance for the prevention of early abnormal vascular architecture. Methods: The data were obtained from the second follow up of the Children Cardiovascular Health Cohort Study conducted from November to December 2021. A total of 1 297 children and adolescents for who completed data relating to sex, age, cIMT, physical examinations, questionnaires variables and blood biochemical indices, were included for analysis. Linear regression analysis was performed to examine trends in the levels of cIMT with exposure to SHS in indoor public places. Multiple linear regression analysis was carried out to assess the association between SHS exposure in indoor public places and cIMT after adjustment for potential covariates. Results: During the previous 7 days, 407 (31.4%) children and adolescents were exposed to SHS in indoor public places for 1-2 days, 86 (6.6%) for 3-4 days, and 82 (6.3%) for ≥5 days. The levels of cIMT in youth increased on different models, with the duration of SHS exposure during the previous 7 days ( t=3.30, 3.05, 2.87, P <0.05). After adjusting for various covariates, the cIMT values of children and adolescents were[0 day:(551.5±29.3) μm, 1-2 days:(554.0±28.6) μm, 3-4 days:(557.0±27.7) μm, ≥5 days:(559.4±27.5) μm]. Compared to those who were not exposed to SHS in indoor public places during the previous 7 days, those exposed for ≥5 days had significantly higher cIMT levels ( β=7.91, 95%CI=1.47-14.34, P <0.05). Conclusion Among children and adolescents, exposure to SHS in indoor public places remains high and is significantly associated with cIMT. The findings highlight the need for stricter regulation and tobacco control policies to provide healthy smoke free environments for children and adolescents, and to reduce the risk of early abnormal vascular architecture.