Impact of Exposure to Environmental Particulate Matter on the Onset of Giant Cell Arteritis

Abstract

ObjectiveAim of the study is to investigate the association between exposure to particulate matter with aerodynamic diameter ≤10μm (PM10) and the development of giant cell arteritis (GCA) and its ischaemic complications.MethodsThis is case‐crossover study on consecutive patients who received a diagnosis of GCA in three hospitals in Northern Italy between 2013 and 2021. The PM10 hourly and daily average concentrations, collected in the Italian monitoring network and archived by ISPRA were determined using European reference. We used a Bayesian hierarchical model to determine patients’ daily exposure to them. We employed conditional logistic regression to estimate the effect of exposure on GCA symptoms onset or ischaemic complications.ResultsWe included 232 patients. A positive association was observed between exposure to PM10 and GCA risk, with an incremental odd of 27.1% (95% CI 5.8‐52.6) for every 10 μg/m3 increase in PM10 concentration within a 60‐day period. We did not find any significant association for shorter periods, nor with ischaemic complications. Subgroup analysis found a significantly higher incremental risk at a 60‐day lag for patients ≥70 years old. Comparing patients who were chronically exposed to high PM10 levels (26.9±13.8 μg/m3) to those who were not (11.9±7.9 μg/m3) revealed that only in the former group there was an association between GCA onset and increased PM10 levels in the preceding 60 days.ConclusionExposure to environmental PM10 in the preceding 60 days seems to be associated with an increased risk of developing GCA, especially in elderly subjects with prolonged exposure to high levels of air pollution.