Impact of E-cigarette Use on Cardiovascular Risk Markers in Elderly Former Smokers: A Systematic Review and Meta-Analysis

Abstract

E-cigarette (EC) use has been associated with several chronic cardiovascular effects. These include arterial stiffness, endothelial dysfunction, and increased oxidative stress. Despite the fact that the use of ECs has been welcomed as potentially less dangerous than alternatives compared to the smoking of conventional cigarettes, the impact that the utilization of ECs has on cardiovascular condition is an issue that is open to a controversial debate. The purpose of this systematic review and meta-analysis was to ascertain the cardiovascular risk of EC smoking as related to that of nonsmoking and conventional smoking. The exhaustive search was conducted on a variety of databases (Scopus, PubMed, Web of Science, and Google Scholar) for identifying cross-sectional studies, randomized controlled trials, and observational cohort studies that were published between 2015 and 2025. Pooled analysis was performed on the data, and the correlation coefficient was estimated through a model of random effects. The heterogeneity was assessed through the publication bias, and the I² statistic was tackled through funnel plots and Egger's test. The overall analysis demonstrated that EC smoking was related to higher vascular stiffness and oxidative stress, although to a lesser degree compared to conventional cigarette smoking. The total effect size indicated a positive but moderate relationship (r = 0.60, 95% CI: 0.45-0.81) between EC smoking and cardiovascular risks. Although the results were encouraging, there was substantial heterogeneity (I² = 99.99%), showing variation in findings. This implies that future research is obligatory to explicate appropriate long-term cardiovascular consequences of EC consumption, especially among dual users.

Keywords: cardiovascular risk (cvr); e-cigarette use; heterogeneity; oxidative stress; vascular stiffness.

Figure 1. PRISMA flowchart

PRISMA, Preferred Reporting Items for Systematic reviews and Meta-Analyses

Figure 2. Intra-review bias assessment using RoS

RoS, Risk of Bias [21,25]

Figure 3. Intra-review bias assessment using NOS

NOS, Newcastle-Ottawa Scale [22-24,26-30]

Figure 4. Funnel plot measuring publication bias in the studies

[21-30]

Figure 5. Forest plot showing the correlation estimates from each study, along with the overall pooled correlation estimate derived using a random-effects model

[21-30]

Figure 6. Subgroup analysis of the included studies examining the correlations between EC use and cardiovascular outcomes, stratified by study characteristics

[21-30]