E-Cigarette Use, Systemic Inflammation, and Depression.

Introduction:
This article summarizes a study examining the relationship between e-cigarette use, depression, and systemic inflammation. The study uses data from the National health and Nutrition Examination Survey (NhaNES) to investigate these associations.

Key Points:

* The study found that e-cigarette users were more likely to be depressed than non-users.
* Systemic inflammation, as measured by C-reactive protein (CRP), was not found to be associated with current e-cigarette use.
* among all categories of e-cigarette use with elevated CRP, a pattern of increased odds of depression compared to the reference group of non-smoking/never-vaping individuals was observed.
* The association between depression and all current e-cigarette use status was not moderated by CRP level.
* Similar findings were found when assessing the effect of distinct e-cigarette use type (exclusive e-cigarette use, dual user, and former smoking e-cigarette user) on depression.
* The study controlled for characteristics that are highly associated with depression such as sex, poverty status, and BMI.
* The results suggest a possible relationship between e-cigarette use, depression, and inflammation.

Main Message:
The study provides evidence that systemic inflammation may be involved in the relationship between depression and e-cigarette use. however, inflammation was not found to moderate the association between vaping and depression in full model analyses. The results indicate that the association between e-cigarette use and depression varies by stratified CRP level, and this pattern persisted for odds of depression among exclusive e-cigarette users. The findings suggest that inflammation may be associated with, predict, or contribute to depression among e-cigarette users as yet unknown. Further research is needed to understand the biologic underpinnings of this association.

Farrell KR, Karey E, Xu S, Gibbon G, Gordon T, Weitzman M. E-Cigarette Use, Systemic Inflammation, and Depression. International journal of environmental research and public health. 2021;18(19). doi:10.3390/ijerph181910402