Abstract
This study investigated the connection between asthma in US individuals and their body roundness index (BRI) and weight-adjusted waist index (WWI). According to data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES), 3609 of the 25,578 persons in the survey who were 18 years of age or older reported having asthma. After adjusting for all confounders, the probability of asthma prevalence increased by 8% for every unit rise in BRI (OR = 1.08, 95% CI 1.06,1.11). The probability of asthma prevalence increased by 16% for every unit rise in WWI (OR = 1.16, 95% CI 1.08,1.25). The BRI and WWI indices were associated with prevalence and were nonlinearly correlated. The inflection points for threshold saturation effects were 4.36 and 10.69, respectively (log-likelihood ratio test, P < 0.05). Relationship subgroup analyses showed that the positive associations between BRI and WWI and asthma were generalized across populations and there was no significant interaction in most subgroups. In addition, sensitivity analyses verified the robustness of these results, further confirming the conclusion of BRI and WWI as independent risk factors for asthma. Finally, receiver operating characteristic (ROC) analysis showed that BRI outperformed WWI in predicting asthma, suggesting the potential of BRI in early asthma screening. Overall, BRI and WWI are independent risk factors for asthma with important clinical applications.