# Effect of conventional cigarettes and e-cigarettes on salivary biomarkers: A systematic review

## TL;DR

This review compares the effects of conventional cigarettes and e-cigarettes on salivary biomarkers but finds insufficient evidence to distinguish their impacts.

## Contribution

The study systematically reviews and compares salivary biomarker effects of e-cigarettes and conventional cigarettes.

## Key findings

- Seven studies were analyzed, but heterogeneity prevented a meta-analysis.
- No clear differences were found between e-cigarettes and conventional cigarettes on salivary biomarkers.
- Sub-group classifications also failed to produce homogeneous data.

## Abstract

E-cigarette consumption is increasing, and like conventional smoking, it can cause some harmful effects. This systematic review compared the effect of conventional cigarettes and e-cigarettes on salivary biomarkers.

The search strategies included electronic databases (Medline/PubMed, Scopus, EMBASE) and related journals up to May 2023. A qualitative assessment was performed on data extracted from the included studies. Seven studies were included in this systematic review (number of patients=563).

Eleven biomarkers were assessed and compared between e-cigarette and conventional cigarette smokers. The data showed that the different effects of electronic and conventional cigarettes on the level of these biomarkers were not achievable. Due to the heterogeneity of the studies (I2 statistic>90%), performing a meta-analysis was impossible. Even after a sub-group classification, homogeneous data were not achieved.

The current data do not provide evidence of obtainable outcomes between conventional cigarettes and e-cigarettes on salivary biomarkers.