Impact of Physical Activity on the Association Between Unhealthy Adolescent Behaviors and Anxiety Among Korean Adolescents: A Cross-sectional Study.

OBJECTIVES: Adolescents who engage in unhealthy behaviors are particularly vulnerable to anxiety. We hypothesized that participation in physical activity could influence the relationship between anxiety and unhealthy behaviors in adolescents. These behaviors include smoking, alcohol consumption, and unsafe sexual activity. METHODS: This study included 50 301 students from the first year of middle school to the third year of high school, all from Korea. The unhealthy adolescent behaviors examined included current alcohol consumption, current smoking, and unsafe sexual behavior. Anxiety levels were assessed using the Generalized Anxiety Disorder-7 questionnaire (GAD-7). RESULTS: The participants had a mean age of 15.19 years and an average GAD-7 score of 4.23. No significant differences were observed in GAD-7 score among exercising participants when categorized by smoking status (p=0.835) or unsafe sexual behavior (p=0.489). In contrast, participants in the non-exercise group who engaged in these behaviors demonstrated significantly higher GAD-7 scores (p<0.001 and 0.016, respectively). The only significant interaction was found between unsafe sexual behavior and exercise (p=0.009). Based on logistic regression analysis, within the non-exercise group, significant positive associations were observed between current smoking and anxiety (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.18 to 1.57), as well as between unsafe sexual behavior and anxiety (OR, 1.33; 95% CI, 1.02 to 1.73). However, within the exercise group, no significant association was found between anxiety and either smoking or unsafe sexual behavior. Furthermore, no significant interaction was observed between unhealthy behaviors and exercise. CONCLUSIONS: These findings are insufficient to conclude that physical activity influences the relationship between unhealthy behaviors and anxiety.

Risk of lymphadenopathy from SARS-CoV-2 vaccination in Korea: a self-controlled case series analysis.

OBJECTIVES: To assess the risk of lymphadenopathy following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. METHODS: A self-controlled case series design was used to determine whether the risk of lymphadenopathy was higher in the 1-day to 42-day risk interval after coronavirus disease 2019 (COVID-19) vaccination compared to the control period. In addition, subgroup analyses were conducted according to baseline characteristics, time since vaccination, and sensitivity analyses adjusted for the length of the risk interval. RESULTS: The risk of developing lymphadenopathy in the risk interval (1-42 days) after COVID-19 vaccination compared to the control period was significantly increased, with a relative incidence (RI) of 1.17 (95% confidence interval [CI], 1.17 to 1.18) when the first, second, and third doses were combined. The RI was greater on the day of vaccination (1.47; 95% CI, 1.44 to 1.50). In subgroup analyses by baseline characteristics, a significantly increased risk or trend toward increased risk was observed in most subgroups except for those aged 70 years and older, with a significant increase in risk in younger individuals, those with a Charlson's comorbidity index <5, and those who received mRNA vaccines (mRNA-1273>BNT162b2). Within the 1-day to 42-day post-dose risk period, the relative risk was highest during the 1-day to 7-day post-dose period (1.59; 95% CI, 1.57 to 1.60) compared to the control period, and then the risk declined. In the sensitivity analysis, we found that the longer the risk window, the smaller the RI. CONCLUSIONS: SARS-CoV-2 vaccination is associated with a statistically significant increase in the risk of lymphadenopathy, and this risk was observed only with mRNA vaccines.