Air pollution and venous thromboembolism: a new link revealed in the MESA study

Interviewer: We're joined today by Prof. Pamela Lutsey from the University of Minnesota to discuss her recent publication on a large observational study that examined the long-term impact of air pollution on the risk of developing venous thromboembolism or VTE. Prof. Pamela Lutsey, thank you very much for joining us today. Can you begin with a brief introduction to the study and its key observations? Prof. Lutsey: Of course. In this study, we used data from the Multi-Ethnic Atherosclerosis Study, or MESA, to evaluate whether air pollution is a risk factor for developing venous thromboembolism. MESA is a large prospective epidemiologic cohort study. In our analysis, we found that over 17 years of follow-up, greater exposure to three different air pollutants was associated with an elevated risk of developing VTE. The air pollutants we studied were fine particulate matter, particles less than 2.5 micrometers, oxides of nitrogen, and nitrogen dioxide. In terms of the magnitude of effect, we found that when we compared one interquartile range, which is the difference between say an individual at the 75th percentile of the distribution versus the 25th percentile of the distribution, we found a 43% greater risk of VTE associated with elevated exposure to PM 2.5, a 2.8 times greater risk of VTE associated with higher exposure to nitrogen dioxide and a 2.3 times greater risk of VTE with greater exposure to oxides of nitrogen. Interviewer: What were the key considerations