食入砷與血管疾病劑量效應關係之長期追蹤研究(3/3)

Context Chronic arsenic exposure has been found to increase the risk of
atherosclerotic diseases. Previous studies were limited by ecological correlation, or
cross-sectional studies and a small number of cases.
Objectives To elucidate the dose-response relationship between ingested arsenic and
cardiovascular mortality in a large-scale follow-up study.
Design, Setting, and Participants This study enrolled 10,133 and 16,718 residents
aged 40 and older from arsenic-exposed and unexposed areas respectively for an
average follow up period of 12 years. Traditional risk factors and arsenic exposure via
drinking water were evaluated through health examination and structured questionnaire
interview.
Main Outcome Measure Deaths from ischemic heart disease and stroke were
ascertained up to December 31, 2004 through linkage with national death certification
profiles. Cox's proportional hazards regression analyses were used to estimate
multivariate-adjusted relative risks of mortality.
Results There were 109,490 and 207,205 person-years observed for exposed and
unexposed cohorts, respectively. There was a significant dose-response relationship
between the mortality from ischemic artery disease and stroke and the arsenic level in
drinking water (P<0.001 trend test). The relative risk was 1.80 (95% confidence interval,
1.36 –2.38) for the highest arsenic level compared with the lowest.
Conclusions There was a significant dose-response relationship between the
cardiovascular mortality and the arsenic level in drinking water. Arsenic is a dominant risk
factor for cardiovascular mortality.