An Elevated METS-IR Index Is Associated With Higher Asthma Morbidity and Earlier Age of First Asthma in US Adults: Results Based on a Cross-Sectional Study.

Objective: The purpose of this study was to evaluate whether there is a correlation between the METS-IR index and asthma among Americans. Methods: In an attempt to establish the relationship between the METS-IR index and asthma prevalence and age at first onset of asthma, we conducted a logistic regression analysis, subgroup analysis, and dose-response curve analysis using the National Health and Nutrition Examination Survey (NHANES) database. Results: In model 3, each unit increase in METS-IR index led to 1.5% increase in asthma prevalence (OR= 1.015, 95% CI: 1.012, 1.018) and an earlier age of onset of asthma by 0.057years (ß= -0.057, 95% CI: -0.112, -0.002).Stratified analysis determined that an increase in METS-IR index was associated with asthma prevalence in almost all subgroups, except in the group where it was not known whether a blood relative had asthma, and a positive linear relationship was found between METS-IR index and asthma prevalence, as well as a linear negative relationship with age at asthma onset. Conclusion: Despite the fact that a direct causal relationship cannot be demonstrated, a higher METS-IR index is positively related to asthma prevalence and correspondingly may result in asthma onset at younger ages.