Short-term effects of ozone air pollution on ischaemic stroke occurrence: a case-crossover analysis from a 10-year population-based study in Dijon, France

Abstract

Objective: To evaluate the association between air pollutants and the occurrence of acute stroke from 10-year population-based study. Methods: The daily stroke count was obtained from Dijon Stroke Register between March 1994 and December 2004. The register recorded all first-ever strokes among residents of Dijon (150 000 inhabitants) in France, using standard diagnostic criteria. Pollutant concentrations (SO 2 , CO, NO 2, O 3 and PM 10 ) were measured hourly. A bi-directional case-crossover design was used to examine the association between air pollutant and stroke onset. The conditional logistic regression model included the meteorological parameters (temperature, relative humidity), influenza epidemics and holidays. Results: The authors collected 493 large artery infarcts, 397 small artery infarcts, 530 cardio-embolic infarcts, 67 undeterminate infarcts, 371 transient ischaemic attacks and 220 haemorrhagic strokes. For single-pollutant model and for a 10 mg/m 3 increase of O 3 exposure, a positive association was observed only in men, over 40 years of age, between ischaemic stroke occurrence and O 3 levels with 1-day lag, (OR 1.133, 95% CI 1.052 to 1.220) and 0-day lag (OR 1.058, 95% CI 0.987 to 1.134). No significant associations were found for haemorrhagic stroke. In two-pollutant models, the effects of O 3 remained significant after each of the other pollutants were included in the model, in particular with PM 10 . A significant association was observed for ischaemic strokes of large arteries (p = 0.02) and for transient ischaemic attacks (p = 0.01). Moreover, the authors found an exposure-response relations between O 3 exposure and ischaemic stroke (test for trend, p = 0.01). An increase in association in men with several cardiovascular risk factors (smoker, dyslipidemia and hypertension) was also observed. Conclusion: These observational data argue for an association between ischaemic stroke occurrence and O 3 pollution levels; these results still need to be confirmed by other studies.

Clearing the Air: A Review of the Effects of Particulate Matter Air Pollution on Human Health

“…A large case-crossover study found an association between other components of air pollution (NO2 and CO) and cerebrovascular disease, but no correlation was noted with changing PM levels [89]. Similarly, a large registry of first-ever strokes found no association with PM 10 for ischemic or hemorrhagic stroke [90].…”

Outdoor Air Pollution and Incidence of Ischemic and Hemorrhagic Stroke

“…1 Several studies have examined the acute effects of outdoor air pollution on stroke using daily time series and case-crossover study designs. [2][3][4][5][6][7][8][9] Although a number of these studies have examined mortality and others have used hospital admissions as a proxy for incident cases, a few have used population case registers, which aim to capture all incident cases. 4,5 A number of these acute effects studies have reported associations between outdoor air pollutants and ischemic stoke, 4,6,7 whereas others have also reported associations with hemorrhagic stroke.…”

“…[2][3][4][5][6][7][8][9] Although a number of these studies have examined mortality and others have used hospital admissions as a proxy for incident cases, a few have used population case registers, which aim to capture all incident cases. 4,5 A number of these acute effects studies have reported associations between outdoor air pollutants and ischemic stoke, 4,6,7 whereas others have also reported associations with hemorrhagic stroke. 8,9 In contrast, although there is an increasing number of studies examining the effects of chronic exposure to outdoor air pollution on cardiovascular mortality using cohort study designs, 10 few have specifically examined stroke mortality.…”

Impact of Particulate Matter Exposition on the Risk of Ischemic Stroke: Epidemiologic Evidence and Putative Mechanisms

“…We have identified 18 studies, which fulfilled these criteria (Table 4). [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] ACUTE EFFECTS OF PARTICULATE MATTER EXPOSURE Although most studies on PM and cardiovascular diseases have been conducted in developed western countries, first impulses for epidemiologic research on IS came from South Korea and Taiwan. 15,22,25 An increase in PM by an interquartile range in Seoul was associated with a 3% higher IS mortality.…”