Does long-term electronic cigarette smoking affect the lungs?

Electronic cigarettes vaporize propylene glycol / glycerin (PG / VG), nicotine and spices. However, the long-term effect of vaporized e-cigarette liquid on lung health is still unknown.

Does long-term electronic cigarette smoking affect the lungs? Researchers performed bronchoscopy on healthy non-smokers, smokers and e-cigarette users to obtain bronchial brush biopsy and lavage samples for proteomic study. The researchers further used in vitro and mouse exposure models to support the findings in human experiments.

Fiberoptic bronchoscopy showed that the respiratory tract of e-cigarette users was loose and erythema. The epithelial cells from biopsy specimens showed that there were differences in the expression of 300 proteins in the respiratory tract of smokers and e-cigarette users, only 78 proteins were differentially expressed in the two groups, and 113 proteins were changed only in e-cigarette users. For example, CYP1B1, MUC5AC and MUC4 levels increased among e-cigarette users. Atomized pg/vg in cultured human respiratory epithelium and nasal mucosal epithelial cells in mice alone caused a significant increase in MUC5AC protein. Researchers also found that e-cigarette liquid can quickly enter cells, and pg/vg can reduce membrane fluidity and damage protein diffusion.

It can be seen that long-term exposure to e-cigarettes has significant biological effects on the lungs, which may be partially mediated by pg/vg. These changes may not be harmless, and may have clinical significance for the occurrence and development of chronic lung disease. Further studies are needed to determine the extent of the effects of e-cigarettes on the lungs.