Deep Functional Phenotyping of the ALA Lung Health Cohort

The goal of this observational study is to learn about lung structure and function in a group of 1000 healthy people aged 25 to 35. The main questions it aims to answer are whether people's bodies, environment, and general lung health are associated with:

• the structure of the participants lungs' airways,
• the structure of blood vessels in the participants lungs and heart, and
• the participants lungs' ability to exchange gases.

Participants will take four different lung function tests to measure lung function, including:

• air movement in the lungs (oscillometry)
• lung size (slow vital capacity (SVC) and functional residual capacity (FRC)
• gas transfer in the lungs (diffusing capacity for carbon monoxide (DLCO).

The parent Lung Health Cohort (LHC) study will leverage the national infrastructure of the American Lung Association's (ALA) Airways Clinical Research Centers (ACRC) to form the first national cohort of adults focused on respiratory health. The parent LHC study will recruit approximately 4000 community-dwelling adults aged 25-35 from metropolitan regions across the U.S. for the purpose of defining lung health and developing targets to intercept chronic lung disease at its earliest stages.

The parent LHC study will be examining a multitude of known and potential factors related to reduced reserve and increased susceptibility to lung disease, such as childhood and adult health status, infections and exposures. Two of the primary outcomes being assessed during this cross-sectional phase of the parent LHC will be spirometry, measured in forced expiratory volume in 1 second (FEV1), respiratory symptoms in relation to environmental exposures, measured in exposure to particulate matter under 2.5 microns in size (PM2.5). These will be assessed in relation to computed tomography (CT) measures of lung injury. The ancillary study expands the phenotyping to include detailed measurements of lung structure and function, including lung volumes, oscillometry, diffusing capacity for carbon monoxide (DLCO), and airway, blood vessel and cardiac morphology by CT. This deeper phenotyping will move the characterization of lung health reserve beyond FEV1, as well as establish a more comprehensive baseline of lung health to allow assessment of susceptibility. Furthermore, the investigators will relate these detailed measures of lung structure and function to modifiable exposures and risk factors that will allow identification of risks to lung health and potential strategies to mitigate risk. The investigators hypothesize that modifiable exposures and risk factors influence lung health by the effects on structural and functional dysanapsis of the airway, parenchyma and pulmonary vasculature, as well as cardiac morphology and gas exchange.