Acute Effects of Electronic Cigarettes and Heated Tobacco Products on Vascular Stiffness: A Systematic Review and Meta-Analysis.

INTRODUCTION Cardiovascular diseases remain the leading cause of mortality worldwide. Emerging risk factors, such as electronic cigarettes and Heated Tobacco Products (HTPs), may contribute to vascular damage. This systematic review and meta-analysis aimed to evaluate the association between nicotine-containing electronic cigarettes and HTPs and arterial stiffness.

Methods

The study followed PRISMA and Cochrane Collaboration guidelines and was registered in the PROSPERO database (ID: CRD42023446895). PubMed, Scopus, Google Scholar, and eLIBRARY databases from January 1, 2000 to July 30, 2024. Outcomes included Pulse Wave Velocity (PWV), Augmentation Index (AIx), Cardio-Ankle Vascular Index (CAVI), ankle- brachial index (ABI).

Results

From 3,705 abstracts, 9 experimental studies (n=190) were included. CAVI and ABI indices were excluded due to limited data. The PWV analysis included 6 studies (n=133) and demonstrated a significant increase following exposure to nicotine-containing products (SMD=1.71 [95% CI: 0.23-3.19, p=0.031]). The AIx analysis included 9 studies (n=190) and also demonstrated a significant increase (SMD=1.05 [95% CI: 0.34-1.76, p=0.008]). Metaregression analyses showed no significant moderating effects of publication year, age, or sex. However, small-study effects and substantial heterogeneity were identified.

Discussion

The study's findings are consistent with previous studies and suggest possible vascular effects of nicotine-containing electronic cigarettes and HTPs. However, limitations require cautious interpretation, and long-term studies are warranted.

Conclusion

Evidence suggests a possible acute increase in arterial stiffness following exposure to nicotine-containing electronic cigarettes and HTPs compared with non-smokers or nicotinefree electronic cigarette users, but certainty is limited by high heterogeneity, small samples, and methodological variability.