Airborne pollutants and lacunar stroke: A case cross-over analysis on stroke unit admissions

Abstract

Particulate air pollution is known to be associated with cardiovascular disease. The relation of particulate air pollution with cere- brovascular disease (CVD) has not been extensively studied, particularly in relation to different subtypes of stroke. A time-series study was conducted to evaluate the associa- tion between daily air pollution and acute stroke unit hospitalizations in Mantua, Italy. We analyzed 781 CVD consecutive patients liv- ing in Mantua county admitted between 2006- 08. Data on stroke types, demographic vari- ables, risk factors were available from the Lombardia Stroke Registry. Daily mean value of particulate matter with a diameter <10 μm (PM10), carbon monoxide, nitric oxide, nitro- gen dioxide, sulphur dioxide, benzene and ozone were used in the analysis. The associa- tion between CVD, ischemic strokes subtypes and pollutants was investigated with a case- crossover design, using conditional logistic regression analysis, adjusting for tempera- ture, humidity, barometric pressure and holi- days. Among the 781 subjects admitted 75.7% had ischemic stroke, 11.7% haemorrhagic stroke 12.6% transient ischemic attack. In men admission for stroke was associated with PM10 [odds ratio (OR) 1.01, 95%; confidence interval (CI) 1.00-1.02; P<0.05]. According to the clinical classification, lacunar anterior cir- culation syndrome stroke type was related to PM10 level registered on the day of admission for both genders (OR: 1.01, 95%; CI: 1.00-1.02; P<0.05) while for total anterior circulation syndrome stroke only in men (OR: 1.04, 95%; CI 1.01-1.07; P<0.05). In conclusion, our study confirms that air pollution peaks may contribute to increase the risk of hospitalization for stroke and particu- late matter seems to be a significant risk fac- tor, especially for lacunar stroke. © F. Corea et al., 2012.