Ambient Particulate Matter Exposure and Red Blood Cell Distribution Width (RDW): Results from a Cross-Sectional Linkage Study in Portugal

BACKGROUND AND AIM: Ambient particulate matter (PM) is now a well-established risk factor to develop cardiovascular diseases. Multiple studies have linked PM exposure to cardiovascular events, but the pathophysiologic mechanisms linking the occurrence of these events with PM exposure are still an area of intensive debate. red blood cell distribution width (RDW), a blood parameter used to measure the variability sizes of the red blood cells, has been associated with a vast array of human pathologies, including cardiovascular diseases. The present study aims to estimate the long-term effect of PM10 exposure on RDW, in the adult Portuguese mainland population. METHODS: Our study was based on 2211 participants of the 1st Portuguese Health Examination Survey (INSEF, 2015) with available data on RDW parameter and living within a 30km radius of an air quality monitoring station from the air quality monitoring network of the Portuguese Environment Agency with available PM10 measurements. Generalized linear models were used to assess the effect of 1-year PM10 exposure on RDW values. RESULTS:We found an association between long-term exposure to PM10 and RDW values (2.82% RDW increase per each 10 µg/m3 PM10 increment, 95% CI: 0.62%; 5.02%), particularly among males (2.96% RDW increase per each 10 µg/m3 PM10 increment, 95% CI: 0.80–5.12), which is well supported by the sensitivity analysis. CONCLUSIONS:To the best of our knowledge, this is the first study describing an association between ambient PM10 exposure and RDW values. It is uncertain whether changes in RDW due to PM10 exposure constitute an adverse health outcome. However, RDW has been identified as an independent prognostic biomarker of multiple cardiovascular diseases, therefore we consider this result to be of special relevance in particular to explain the effect of PM10 in triggering cardiovascular events. KEYWORDS: Particulatte Matter, RDW, INSEF, Portugal