Vaping disrupts ventilation-perfusion matching in asymptomatic users.

Introduction:
This article reports a study that aimed to investigate the effects of vaping on pulmonary gas exchange and ventilation-perfusion (V/q) matching in young, asymptomatic e-cigarette users. The study used proton magnetic resonance imaging (MRI) techniques to quantitatively assess the distribution of ventilation, perfusion, and V/q mismatch in the lungs of vapers and non-vaping controls.

Key Points:

* The study included nine young, asymptomatic e-cigarette users with a history of vaping for at least 1 year and seven non-smoking, non-vaping, healthy normal subjects as controls.
* The vapers were imaged twice, once at baseline and immediately after vaping, while the controls were imaged only at baseline.
* The study used proton density imaging, arterial spin labeling (aSL) with a flow-sensitive alternating inversion recovery (FaIRER) imaging sequence, and specific ventilation imaging to quantify lung density, perfusion, and ventilation.
* The study found that vaping increased ventilation heterogeneity and decreased perfusion heterogeneity, suggesting impairment of hypoxic pulmonary vasoconstriction.
* The study also found that vapers had greater V/q mismatch at baseline compared to controls, which worsened after vaping.
* The changes in ventilation and perfusion distributions, both at baseline and acutely after vaping, and the potential implications on hypoxic vasoconstriction are particularly relevant in understanding the pathogenesis of vaping-induced dysfunction.
* The imaging-based approach provides evidence of potential subclinical alterations in lung function below thresholds of detection using spirometry.

Main Message:
The study provides evidence of vaping-induced disruptions in V/q matching in young, healthy, asymptomatic adults with normal spirometry who habitually vape. The changes in ventilation and perfusion distributions, both at baseline and acutely after vaping, and the potential implications on hypoxic vasoconstriction are particularly relevant in understanding the pathogenesis of vaping-induced dysfunction. The study's imaging-based approach provides evidence of potential subclinical alterations in lung function below thresholds of detection using spirometry. These findings suggest that vaping may have detrimental effects on lung function, even in asymptomatic individuals, and highlight the need for further research to understand the long-term health consequences of vaping.

Kizhakke Puliyakote aS, Elliott aR, Sá RC, anderson KM, Crotty alexander LE, hopkins SR. Vaping disrupts ventilation-perfusion matching in asymptomatic users. Journal of applied physiology (Bethesda, Md : 1985). 2021;130(2):308-317. doi:10.1152/japplphysiol.00709.2020