Figure 1.
Associations between the genetic risk score (GRS) and lung function, sequentially adjusted by features of lung structure on computed tomography (CT). Number of participants: 2,517 in MESA (Multi-Ethnic Study of Atherosclerosis) analyses and 2,339 in SPIROMICS (Subpopulations and Intermediate Outcome Measures in COPD Study) analyses. The linear regression model was adjusted for age, age2, sex, height, smoking status, pack-years, principal components of ancestry 1–10, site, CT model, body mass index high/low, total imaged lung volume, and lobe. The percent attenuation of the main effect estimate after additional adjustment for CT lung structural element(s) is calculated as [(original effect estimate − adjusted effect estimate)/original effect estimate] × 100. The statistical significance of potential mediational effects was evaluated by the Sobel (cross-product) method. COPD = chronic obstructive pulmonary disease; PRMfSAD = parametric response mapping of functional small airway disease; Ref. = reference.