PT  - JOURNAL ARTICLE
AU  - Qiu, Hong
AU  - Sun, Shengzhi
AU  - Tsang, Hilda
AU  - Wong, Chit-Ming
AU  - Lee, Ruby Siu-yin
AU  - Schooling, C. Mary
AU  - Tian, Linwei
TI  - Fine particulate matter exposure and incidence of stroke
AID  - 10.1212/WNL.0000000000003903
DP  - 2017 May 02
TA  - Neurology
PG  - 1709--1717
VI  - 88
IP  - 18
4099  - http://n.neurology.org/content/88/18/1709.short
4100  - http://n.neurology.org/content/88/18/1709.full
SO  - Neurology2017 May 02; 88
AB  - Objective: We aimed to assess the association of long-term residential exposure to fine particulate matter (PM) with aerodynamic diameter less than 2.5 μm (PM2.5) with the incidence of stroke and its major subtypes.Methods: We ascertained the first occurrence of emergency hospital admission for stroke in a Hong Kong Chinese cohort of 66,820 older people (65+ years) who enrolled during 1998–2001 (baseline) and were followed up to December 31, 2010. High-resolution (1 × 1 km) yearly mean concentrations of PM2.5 were predicted from local monitoring data and US National Aeronautics and Space Administration satellite data using linear regression. Baseline residential PM2.5 exposure was used as a proxy for long-term exposure. We used Cox proportional hazards to evaluate the risk of incident stroke associated with PM2.5 exposure adjusted for potential confounders, including individual and neighborhood factors.Results: Over a mean follow-up of 9.4 years, we ascertained 6,733 cases of incident stroke, of which 3,526 (52.4%) were ischemic and 1,175 (17.5%) were hemorrhagic. The hazard ratio for every 10 μg/m3 higher PM2.5 concentration was statistically significant at 1.21 (95% confidence interval [CI] 1.04–1.41) for ischemic and non-statistically significant at 0.90 (95% CI 0.70–1.17) for hemorrhagic stroke in fully adjusted model 3. The estimates for ischemic stroke were higher in older participants (>70 years), less educated participants, and in men for current smokers.Conclusion: Long-term PM2.5 exposure was associated with higher risk of incident ischemic stroke, but the association with incident hemorrhagic stroke was less clear.AOD=aerosol optical depth; BMI=body mass index; CI=confidence interval; COPD=chronic obstructive pulmonary disease; EPD=Environmental Protection Department; ESCAPE=European Study of Cohorts for Air Pollution Effects; HR=hazard ratio; ICD-9=International Classification of Diseases–9; NASA=National Aeronautics and Space Administration; PM=particulate matter; PM2.5=particulate matter with aerodynamic diameter less than 2.5 μm; SEC=surface extinction coefficients