More evidence that e-cigarettes harm smokers more than just smoking cigarettes

Tingting Yao and our colleagues just published “Relationship between spending on electronic
cigarettes, 30-day use, and disease symptoms among current adult cigarette smokers in the U.S.” in PLOS ONE.  This paper shows that smokers who use e-cigarettes report having more chest pain, are more likely to notice blood when brushing their teeth, to have sores or ulcers in their mouth, and to have more than one cold than smokers who did not use e-cigarettes in the last 30 days.  Even after controlling for cigarettes smoked per day, e-cigarette expenditures or use was associated with greater odds of wheezing and shortness of breath. 
 
This paper adds to the evidence that dual use of e-cigarettes with cigarettes is more dangerous than smoking cigarettes.
 
Another interesting finding is that the amount of money spent on e-cigarettes is a better predictor of health effects than reported e-cigarette use.  This variable may capture differences in e-cigarette systems as well as how heavily they are used.
 
Here is the abstract:
 
Objective:  To examine the relationship between spending on electronic cigarettes (e-cigarettes) and disease symptoms compared with the relationship between 30-day e-cigarette use and disease symptoms among adult cigarette smokers in the U.S.
Methods: We analyzed data from the Tobacco and Attitudes Beliefs Survey which included 533 respondents aged 24+ who were current cigarette smokers and e-cigarette ever users. Fifteen self-reported disease symptoms were included as outcome variables. Separate multivariable logistic regression models were estimated for each disease symptom with total spending on e-cigarettes in the past 30 days and with reported 30-day e-cigarette use. All models controlled for cigarettes smoked per day (CPD) and sociodemographic characteristics.
Results:  We found that those who spent more on e-cigarettes were more likely to report chest pain (AOR = 1.25, 95% CI 1.02–1.52), to notice blood when brushing their teeth (AOR = 1.23, 95% CI 1.02–1.49), to have sores or ulcers in their mouth (AOR = 1.36, 95% CI 1.08–1.72), and to have more than one cold (AOR = 1.36, 95% CI 1.05–1.78) than those with no spending on e-cigarettes in the past 30 days in an adjusted analysis. After controlling for CPD and other covariates, there were no significant relationships between 30-day e-cigarette use and symptoms. Even after controlling for CPD, e-cigarette expenditures or use was associated with greater odds of wheezing and shortness of breath.
Conclusions:  E-cigarette expenditures might be a more useful measure of intensity of e-cigarette use. The additional health effect of e-cigarette use or expenditures among smokers independent of the effect of CPD suggests that e-cigarette use adds adverse health effects even among cigarette smokers.
 
The full citation is  Yao T, Max W, Sung H-Y, Glantz SA, Goldberg RL, Wang JB, et al. (2017) Relationship between spending on electronic cigarettes, 30-day use, and disease symptoms among current adult cigarette smokers in the U.S. PLoS ONE12(11): e0187399.  https://doi.org/10.1371/journal.pone.0187399. It is available here for free.