Vaping and blood lipids: an unfavorable association, but highly uncertain evidence

A review focused on blood lipids

The researchers searched for studies available through May 31, 2025, on the association between exclusive e-cigarette use and blood lipids in adults. The seven included studies came from the United States, South Korea, Romania and Iraq.

The analysis covers several markers, including total cholesterol, LDL, HDL and triglycerides. The abstract consulted does not provide enough information about the comparison groups or study durations to describe these elements in detail. It therefore does not allow all participants to be treated as though they had been followed under a shared protocol.

Associations that do not translate into individual risk

For high triglycerides, the pooled adjusted odds ratio was 3.10, with a 95% confidence interval of 1.18 to 8.16. For low HDL, it was 3.26, with an interval of 2.28 to 4.65. These odds ratios do not mean that every person who vapes has three times the risk. The absolute frequencies needed to translate these associations into a difference in risk are not provided in the abstract.

In analyses of unadjusted mean concentrations, LDL was higher by an average of 12.40 mg/dL, with a 95% confidence interval of 7.91 to 16.88 mg/dL. By contrast, no statistically significant difference was found for total cholesterol. These unadjusted comparisons cannot isolate the role of vaping from that of other participant characteristics.

Why the conclusion remains tentative

All the studies are observational. They can identify an association, but are not sufficient to establish causality. Results for triglycerides varied substantially between studies, and some analyses showed signs of asymmetry that could suggest publication bias.

The authors rate the certainty of evidence as very low for every lipid outcome. They were also unable to conduct the planned analyses by age and sex because sufficiently detailed data were lacking.

This review therefore raises a question about the lipid profiles of e-cigarette users without establishing a clinical cardiovascular effect. Nor can it settle the comparison between vaping and combustible cigarette smoking. The authors call for longitudinal studies with better exposure measurement, repeated lipid testing and more comprehensive accounting for cardiometabolic factors.

What we can take away

The signal deserves investigation, not a promotion to certainty: vaping is associated with certain lipid abnormalities in this review, but their origin and clinical significance remain undetermined.