[The association between secondhand smoke exposure and overweight/obesity among children and adolescents]

This study aimed to investigate the association between secondhand smoke exposure in different places and overweight/obesity among children and adolescents. Children and adolescents aged 7 to 18 years old in Hunan Province were recruited for questionnaire surveys and physical examinations using a multi-stage stratified cluster sampling method. Secondhand smoke exposure was evaluated according to the answer to the question, "Has someone smoked in front of you in the last 7 days?". Overweight and obesity were determined using BMI-for-age and BMI-for-sex according to the national standard WS/T586-2018. Multivariate logistic regression was used to explore the association between secondhand smoke exposure in different places and overweight/obesity among children and adolescents. A total of 187 863 participants were included in this study, with a prevalence of overweight and obesity of 28.4%. The prevalence of secondhand smoke exposure at home, school and other public places was 25.5%, 12.6% and 32.3%, respectively. Children and adolescents with secondhand smoke exposure at home, school and other public places had a higher prevalence of overweight and obesity than those without exposure. After adjusting for confounding factors, secondhand smoke exposure was positively associated with overweight and obesity among children and adolescents, and exposure at home showed the closest association (OR=1.091; 95%CI: 1.066-1.117). In conclusion, secondhand smoke exposure, especially at home, significantly increases the risk of overweight and obesity among children and adolescents. Comprehensive strategies should be implemented to avoid secondhand smoke exposure and protect children and adolescents from overweight and obesity.