The relationship between body mass index and bronchial hyperresponsiveness showing the mediating effect of airway closure (percentage change in forced vital capacity (FVC) from baseline to the end of the methacholine challenge)

CoefficientStandard errorp-value95% CI
Indirect effect0.07410.03010.0140.0152–0.1331
Direct effect0.09830.04340.0240.0132–0.1833
Total effect0.17240.05540.0020.0638–0.2810

Model adjusted for baseline forced expiratory volume in 1 s to FVC ratio, asthma status, socioeconomic status, sex and smoking.