Skip to main content

Volume 73 Supplement 1

Methods in Epidemiology Symposium

Changes in miRNA expression and retinal blood vessels are associated with short-term air pollution exposure.

Air pollution, a cardiovascular risk factor, might exert its effects through the microcirculation. Fundus photography allows study of the retinal vasculature in vivo. Short-term PM10 exposure is associated with changes in retinal blood vessels, but the underlying mechanism remains unknown. Expression of MIR21, MIR222 and MIR146A, gene regulators involved in oxidative stress and inflammatory processes, can be changed by air pollution and might be a pathway explaining the association between PM10 and microvascular changes.

50 healthy adults (50% women, 50% men, 23-58 years old) were sampled once a month from December 2014 until April 2015. At each study visit fundus photos and venous blood samples were collected. PM10 data were obtained from a nearby monitoring station. Image analysis was used to calculate the width of retinal blood vessels, represented as the Central Retinal Arteriolar/Venular Equivalent (CRAE/CRVE). miRNA was isolated from blood and expression was measured using qRT-PCR. Mixed models were used for statistical analysis.

Short-term changes in PM10 exposure were associated with changes in CRAE, CRVE and miRNA-expression. Each 10 μg/m3 increase in PM10 during the previous 24 hours was associated with a 0.58 μm decrease (95% CI: -1.16, -0.0005; p=0.056) in CRAE, a 0.99 μm increase (95% CI: 0.18, 1.80; p=0.021) in CRVE, a 6.6% decrease (95% CI: -11.07, -2.17; p=0.0038) in miR-21 expression and a 6.7% decrease (95% CI: -10.70, -2.75; p=0.0012) in miR-222 expression. miRNA expression was associated with CRAE and CRVE. Each 10% increase in miR-21 expression and miR-222 was associated with respectively a 0.14 μm increase (95% CI: 0.0060, 0.24; p=0.046) in CRAE and a 0.28 μm decrease (95% CI: -0.50, -0.062; p=0.016) in CRVE.

PM10 exposure affects miRNAs involved in inflammation and oxidative stress. These changes may be an underlying mechanism for the association between PM10 exposure and retinal arteriolar narrowing and venular widening.

Author information

Authors and Affiliations


Rights and permissions

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Louwies, T., Int Panis, L., De Boever, P. et al. Changes in miRNA expression and retinal blood vessels are associated with short-term air pollution exposure.. Arch Public Health 73 (Suppl 1), P24 (2015).

Download citation

  • Published:

  • DOI: