A study recently published in Ophthalmology evaluated the association between electronic cigarette (e-cig) use and the development of uveitis.
Give me some background.
E-cigs are devices that produce a heated aerosol from nicotine-containing e-liquid.
A previous study found that the sputum from e-cig users contained increased levels of oxidative stress-related proteins that were implicated in the development of uveitis.
Meaning: There is a potentially heightened risk of uveitis in patients who use e-cigs.
Now talk about the study.
In this retrospective study, investigators utilized the TriNetX database to recruit 419,325 e-cig users and 419,325 non-users with a similar racial distribution to compare the prevalence of uveitis development.
- TriNetX is a global database containing de-identified data from over 100 million patients.
Primary outcome measure: The incidence of new-onset uveitis.
Who was included?
E-cig users were selected based on factors such as:
- International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes for vaping (U07.0) and unspecified nicotine dependence (F17.20)
- Patients aged 18 years or older who were seen at least twice in any healthcare setting between September 2019 and December 2023
E-cig users were excluded if they had a previous history of smoking traditional cigarettes or comorbid conditions that may influence the risk of uveitis.
Findings?
E-cig users were associated with an increased risk for uveitis compared to non-users (hazard ratio [HR] 2.53, 95% confidence interval [CI] 2.33-2.76).
Subgroup analyses revealed an increased risk of uveitis among e-cig users for specific age groups:
- 18-39 years: HR 2.59, 95% CI 2.11-3.17
- 40-64 years: HR 2.20, 95% CI 1.95-2.48
- ≥65 years: HR 3.15, 95% CI 2.72-3.64
Anything else?
The risk for uveitis development continued throughout the 4-year follow-up period, suggesting that the effect of e-cig use on uveitis risk was both short- and long-term.
Traditional cigarette use was also linked with an increased risk of uveitis (HR 1.28), but significantly less than e-cigs.
Further, patients with a history of both traditional and e-cigs had a higher risk of uveitis than those who only used traditional cigarettes.
Limitations?
These included:
- A lack of information on the duration and quantity of cigarette exposure
- Researchers could not isolate the effect of secondhand exposure to vaping or traditional cigarettes
- The retrospective design means the direct causation between e-cig use and uveitis cannot be definitively established
Take home.
These findings suggest there is an increased risk for uveitis in e-cig users compared to non-users.
The study authors recommended that clinicians caring for patients with a history of e-cig use be aware of the potentially increased risk of new-onset uveitis.