Exclusive e-cigarette use raises COPD risk but not type 2 diabetes or heart failure risk
Key takeaways:
- Exclusive e-cigarette use negatively impacts COPD risk.
- Researchers observed a heightened risk for five individual cardiometabolic conditions with combustible cigarette use only.
Individuals using e-cigarettes exclusively had a significantly elevated risk for COPD, whereas this was not found when assessing the risk for type 2 diabetes or heart failure, according to data published in Nicotine and Tobacco Research.
“For clinicians, these results offer helpful information about how e-cigarettes compare to regular cigarettes in terms of health risks,” John Erhabor, MD, MPH, research postdoctoral fellow at Johns Hopkins Medicine, told Healio. “While e-cigarettes may have fewer heart and metabolic risks than regular cigarettes, they are still tied to certain problems like COPD and possibly high blood pressure in some age groups.
“Doctors should take these differences into account when advising patients and make clear that switching completely from regular cigarettes to e-cigarettes may potentially lower health risks, but using both does not offer the same benefit,” Erhabor said.
In this longitudinal study, Erhabor, Michael J. Blaha, MD, MPH, professor of medicine and director of clinical research at the Ciccarone Center for the Prevention of Cardiovascular Disease at Johns Hopkins Medicine, and colleagues evaluated 249,190 individuals (mean age, 51 years; 63.8% female; 52% non-Hispanic white; 21.5% non-Hispanic Black) from the All of Us research program to determine how three uses of e-cigarettes and/or combustible cigarettes are linked to the risk for various cardiometabolic conditions.
The three assessed use types included current exclusive e-cigarette use (EE; 1.3%), exclusive combustible cigarette use (ECC; 13.6%) and dual use (3.3%). According to the study, the remaining 81.8% of individuals never used either cigarette.
Hypertension, type 2 diabetes, COPD, heart failure and atherosclerotic cardiovascular disease (ASCVD) made up the studied cardiometabolic conditions.
Within this population, the median follow-up time was 3.7 to 3.9 years, according to the study. Researchers found that the cardiometabolic condition with the highest number of new cases during this time was hypertension at 23,745 cases, followed by type 2 diabetes (n = 13,179), heart failure (n = 9,801), COPD (n = 7,925) and ASCVD (n = 6,139).
Following adjustment for age, sex, race and ethnicity and BMI, researchers reported no significant link between EE use and four of the cardiometabolic conditions vs. nonuse: hypertension, type 2 diabetes, ASCVD and heart failure. The only significant link found in this analysis was between EE use and COPD, demonstrating an elevated risk for COPD with EE use vs. nonuse (adjusted HR = 2.29; 95% CI, 1.42-3.71).
Notably, in addition to COPD, a significant relationship between EE use and a heightened risk for hypertension (aHR = 1.39; 95% CI, 1.09-1.77) was revealed when the analysis was limited to individuals aged 30 to 70 years, according to the study.
In contrast to EE use, researchers observed a significant link between ECC use and risk for each of the studied conditions vs. nonuse:
- COPD (aHR = 6.75; 95% CI, 6.26-7.28);
- ASCVD (aHR = 1.66; 95% CI, 1.51-1.81);
- heart failure (aHR = 1.5; 95% CI, 1.4-1.62);
- hypertension (aHR = 1.2; 95% CI, 1.15-1.26); and
- type 2 diabetes (aHR = 1.18; 95% CI, 1.11-1.26).
“One surprising finding of this study was that exclusive e-cigarette use was associated with COPD and newly diagnosed hypertension among middle-aged to older adults; however, it was not associated with other heart or metabolic conditions such as diabetes, heart failure or ASCVD,” Erhabor told Healio. “This starkly contrasts with the broader and more severe health risks linked to combustible cigarette use, which is strongly associated with all conditions, including a several-fold stronger association with COPD.”
For all cardiometabolic conditions except type 2 diabetes, dual e-cigarette and combustible cigarette use significantly raised the risk for each one: COPD (aHR = 7.91; 95% CI, 6.91-9.06), ASCVD (aHR = 2.18; 95% CI, 1.82-2.62), heart failure (aHR = 1.76; 95% CI, 1.49-2.07) and hypertension (aHR = 1.21; 95% CI, 1.1-1.34). Researchers noted that these adjusted risks were higher than or similar to the adjusted risks seen with ECC use.
Reflecting on study findings, Erhabor told Healio there have been limited studies on e-cigarettes that are large, high-quality and long-term.
“Our study offers new evidence that is crucial for evaluating where e-cigarettes stand on the tobacco risk continuum,” Erhabor said. “It provides valuable evidence that demonstrates how e-cigarettes compare with other tobacco products in terms of health risks.
“While exclusive e-cigarette use may be less harmful than smoking, the potential benefits are mainly observed when individuals completely switch from combustible cigarettes,” he continued.
In addition to having an impact on health, Blaha told Healio these findings impact tobacco product regulation.
“Few studies can address the comparative harms of different tobacco products on cardiometabolic health over longitudinal follow-up,” Blaha said. “Our data will allow agencies like the FDA to incorporate data on the continuum of risk across tobacco products into the evidence-based tobacco regulatory framework.”
Looking ahead, Erhabor said further research on this topic should measure outcomes after more than 3.7 to 3.9 years of follow-up.
“Future studies will likely follow participants over a longer period to better understand how e-cigarette use affects health over time,” Erhabor told Healio. “They may also focus on recruiting more people who exclusively use e-cigarettes and explore additional outcomes, which may uncover new associations. Newer studies may include biological tests, such as blood markers or lung function measures, which could serve as surrogates for health outcomes.”
For more information:
John Erhabor, MD, MPH, can be reached at johnerhabor@gmail.com.
Michael J. Blaha, MD, MPH, can be reached at mblaha1@jhmi.edu.
Reference:
- New analysis underscores health risks of e-cigarettes. https://www.hopkinsmedicine.org/news/newsroom/news-releases/2025/04/new-analysis-underscores-health-risks-of-e-cigarettes. Published April 15, 2025. Accessed April 15, 2025.
Perspective
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This study examined de-identified data from the All of Us research program to identify associations with cardiometabolic conditions (ie, hypertension, type 2 diabetes mellitus, COPD, heart failure and ASCVD). Self-reported and linked electronic health record data from 249,190 individuals who had varying tobacco and nicotine current use or never use history (3,164 exclusive e-cigarette; 33,778 exclusive combustible cigarettes; 8,316 dual use of e-cigarettes and cigarettes; 203,932 never use) were used to examine these associations. The researchers found an association between exclusive e-cigarette use and COPD, and among an age-restricted sub-analysis, an association with hypertension. Exclusive and dual use of cigarettes were strongly associated with all cardiometabolic conditions.
This study has strengths including longitudinal follow up (3.7-3.9 years), linked EHR data confirming cardiometabolic diagnosis, exclusion of individuals with former tobacco/nicotine use and a large representative sample of individuals. The risks associated with exclusive cigarette use are well documented, and these data further contribute to a longstanding body of research that documents the risk of using combustible tobacco products and, now, the potential additional risk for dual use of both cigarettes and e-cigarettes.
The results related to the development of COPD among individuals who reported exclusive e-cigarette use within 3.7 to 3.9 years are surprising, particularly since the average age for individuals who primarily used e-cigarettes was 29.2 years. In the age-restricted analyses, which limited the inclusion to individuals aged 30 to 70 years, exclusive e-cigarette use was significantly associated with hypertension and COPD. There is little discussion about why it would be expected that COPD would be likely to develop in 3 to 4 years’ time, particularly for younger individuals. The development of COPD typically takes several decades, but exposures to environmental pollutants, occupational exposures, genetics and smoking history can increase the risk for developing COPD.
A study conducted in Denmark examined the risk of developing COPD in a general population sample (n = 8,045) across 25 years. Among individuals who smoked in the sample, at least 25% developed clinically significant COPD and 30% to 40% developed “any COPD.” The authors also found that quitting smoking early in the observation period was an important protective factor, with none of the “early quitters” with complete follow-up data developing severe COPD and the number of deaths from COPD was much lower than the number of individuals who smoked. However, these study findings were published prior to the global marketing of e-cigarettes. Given the lower toxicant profile of e-cigarettes compared with cigarettes, it is surprising that a diagnosis of COPD occurred within 3 to 4 years of exclusive e-cigarette use.
While the authors highlight that individuals with pre-existing health conditions and those who had a previous history of tobacco use were excluded from analyses, it is not clear which and what conditions were excluded and how many individuals this included. Additional information related to the length, intensity and frequency of e-cigarette use, the types of e-cigarette devices/flavors used by individuals, and cannabis use would be useful information to include in future analyses of these data.
Overall, these findings provide additional data that highlight that, while likely less harmful than cigarettes, e-cigarettes are not risk free and support the growing literature around the potential harms associated with the dual use of both cigarettes and e-cigarettes. Additionally, these data highlight the importance of national, longitudinal cohort surveillance studies to provide data for researchers, health professionals and the public to better understand how behavioral and environmental factors may impact health outcomes.
Reference:
Løkke A, et al. Thorax. 2006;doi:10.1136/thx.2006.062802.
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