An 18 year data-linkage study on the association between air pollution and acute limb ischaemia

Abstract

Background: There is limited information regarding the effects of air pollutants, such as nitrogen oxides (NOx) nitric oxide (NO2), nitrous oxide (NO) and particulate matter with a diameter smaller than 10 mu m (PM10), on acute limb ischaemia (ALI), a peripheral arterial disease (PAD) often with a poor clinical outcome. Patients and methods: We conducted an 18-year retrospective cohort study using routinely collected healthcare records from Ninevvells Hospital, Dundee, and Perth Royal Infirmary, in Tayside, Scotland, UK from 2000 to 2017. ALI hospitalisation events and deaths were linked to daily NOx, NO2, NO and PM10 levels extracted from publicly available data over this same time period. Distributed tag models were used to estimate risk ratios for ALI hospitalisation and for ALI mortality, adjusting for temperature, humidity, day of the week, month and public holiday. Results: 5,608 hospital admissions in 2,697 patients were identified over the study period (mean age 71.2 years, +/- 11.1). NOx and NO were associated with an increase of ALI hospital admissions on days of exposure to pollutant (p=.018), white PM10 was associated with a cumulative (tag 0-9 days) increase (p=.027) of ALI hospital admissions in our study. There was no increase of ALI mortality associated with pollution levels. Conclusions: ALI hospital admissions were positively associated with ambient NOx and NO on day of high measured pollution levels and a cumulative effect was seen with PM10.