RESUMO
Limited evidence is available regarding the association between acute exposure to ambient air pollutants and the risk of urticaria, even though the skin is an organ with direct contact with the external environment. This study utilized generalized additive models to investigate the association between particulate matter with an aerodynamic diameter smaller than 10 µm (PM10) and 2.5 µm (PM2.5), nitrogen dioxide (NO2) and sulfur dioxide (SO2), and daily outpatient visits for urticaria in Guangzhou, China from 2013 to 2017. We also estimated the attributable fraction of urticaria outpatient visits due to air pollution. A total of 216,648 outpatient visits due to urticaria occurred during the study period. All air pollutants were significantly associated with an increased excess risk of urticaria. Each 10 µg/m3 increase in PM2.5, PM10, NO2, and SO2 was associated with an increase of 1.23% (95% CI: 0.42%, 2.06%), 0.88% (95% CI: 0.28%, 1.49%), 3.09% (95% CI: 2.16%, 4.03%), and 2.82% (95% CI: 0.93%, 4.74%) in hospital visits for urticaria at lag05, respectively. It was estimated that 3.77% (95% CI: 1.26%, 6.38%), 1.91% (95% CI: 0.60%, 3.26%), 6.36% (95% CI: 4.38%, 8.41%), and 0.08% (95% CI: 0.03%, 0.14%) of urticaria outpatient visits were attributable to PM2.5, PM10, NO2, and SO2 using the World Health Organization's air quality guideline as the reference. Relatively stronger associations were observed during the cold season. This study indicates that short-term air pollution may play a significant role in outpatient visits for urticaria, and that such relationships could be modified by season.
RESUMO
BACKGROUND: Adolescent obesity can lead to long-term health problems and is a topic of major concern in pediatric and broader medical and public health spheres. Numerous national and state-wide initiatives aimed at increasing physical activity and/or improving nutrition in this age group have assumed the goal of reducing the prevalence adolescent obesity. OBJECTIVES: We assess trends in U.S. adolescent physical activity and body mass index between 1999 and 2019. METHODS: Using data from the U.S. Youth Risk Behaviour Surveillance System, we analyse data from 144 544 14-to-18-year-old respondents. We use multilevel linear and logistic regression to perform age-period-cohort analyses attributing changes in physical activity and body mass index over time to these three sources. RESULTS: Age and period effects are strong in all outcomes studied. Physical activity consistently decreases with age across the study period. Age trends in obesity have reversed in recent years, with older adolescents now more likely to be have obesity than younger adolescents. Both female and Asian adolescents report less physical activity but lower rates of obesity than their male and non-Asian counterparts. CONCLUSIONS: The reversal of obesity trends by age with little change in physical activity over the study period suggests other lifestyle factors have changed over the study period to increase the prevalence of obesity in older adolescents.