Association between Asthma, Obesity, and Metabolic Syndrome in Adolescents and Young Adults.

Background. The association of asthma and metabolic syndrome (MetS) among adolescents and young adults (AYAs) remains unclear, as well as the role of obesity in this relationship. Methods. AYAs aged 12-25 years who participated in the 2011-2020 National Health and Nutrition Examination Survey were included in this cross-sectional analysis. The moderating effect of obesity (age- and sex-adjusted body mass index ≥ 95th%ile for adolescents or ≥ 30kg/m 2 for adults) on asthma and MetS were evaluated in four groups: 1) both asthma and obesity; 2) asthma and no obesity; 3) obesity and no asthma; and 4) healthy controls with no obesity/asthma. Results. A total of 7,709 AYAs (53.9% aged 12-18 years, 51.1% males, and 54.4% non-Hispanic White) were included in this analysis. 3.6% (95% CI 2.8-4.3%) had obesity and asthma,7.6% (95% CI 6.8-8.4%) had asthma and no obesity, 21.4% (95% CI 19.6-23.2%) had obesity and no asthma, and 67.4% (95% CI 65.4-69.4%) had neither obesity nor asthma. The estimated prevalence of MetS was greater among those with both obesity and asthma versus those with only asthma (4.5% [95% CI 1.7-7.3%] vs. 0.2% [95% CI 0-0.5%], P < 0.001). Compared to healthy controls, those with both obesity and asthma had ∼10 times higher odds of having MetS (aOR 10.5, 95% CI 3.9-28.1). Conclusions. Our results show the association between MetS and asthma is stronger in AYAs with BMI-defined obesity. Efforts to prevent and treat obesity may reduce MetS occurrence in AYAs with asthma.