YIA 02-02 LONG-TERM EFFECTS OF FINE PARTICULATE MATTER EXPOSURES ON MAJOR ADVERSE CARDIOVASCULAR EVENTS.

OBJECTIVE: Epidemiological studies have been published acute or chronic adverse association between ambient particulate matter and cardiovascular/respiratory diseases. Recently, there has been increased interest in investigating the role of fine particulate matter on major adverse cardiovascular event (MACE). For the long-term effects, the external validity of studies has rarely been satisfied due to the representativeness of cohorts. The aim of this study was to investigate the potential impact of fine particulate matter long-term exposure on MACE, defined as time to incidence of acute myocardial infarction, ischemic stroke, hemorrhagic stroke, or death due to cardiovascular cause.

DESIGN AND METHOD: We analyzed the effects of fine particulate matter on first hospital diagnosis for MACE among nationwide representative cohort of 1,025,340 participants, or 2% of the National Health Insurance Service enrollees in Korea (2002-2013). For participants who live in Seoul, a Cox proportional hazards model was used with adjustment for age, sex, income, insurance type, and past history. Annual mean concentration was calculated with annual 25 district-wide measurements from 2002 to 2013.

RESULTS: We followed approximately 12 years for 99,038 subjects (13,151 subjects with hypertension and 85,887 participants without hypertension) and observed significant associations of long-term fine particulate matter exposure with 5,662 MACE events. Specifically, estimated hazard ratio was 1.015 (95% CI: 1.004-1.027) for MACE per 1 μg/m3 increase in fine particulate matter exposure. Hazard ratio among hypertension patients was not statistically significant; 1.004 (95% CI 0.988-1.020) and that among participants without hypertension was 1.026 (95% 1.010-1.042).

CONCLUSIONS: To the best of our knowledge, this is the first study to investigate the effect modification, by hypertension past history, in the chronic effect of fine particulate matter exposure on MACE incidence. Findings provide the basis for public health implications that long-term exposures could be crucial to cardiovascular event.