Abstract:
(1) Background: American Indians are disproportionately affected by air pollution, an important risk factor for dementia. However, few studies have investigated the effects of air pollution on the risk of dementia among American Indians. (2) Methods: This retrospective cohort study included a total of 26,871 American Indians who were 55+ years old in 2007, with an average follow-up of 3.67 years. County-level average air pollution data were downloaded from land-use regression models. All-cause dementia was identified using ICD-9 diagnostic codes from the Indian Health Service\'s (IHS) National Data Warehouse and related administrative databases. Cox models were employed to examine the association of air pollution with dementia incidence, adjusting for co-exposures and potential confounders. (3) Results: The average PM2.5 levels in the IHS counties were lower than those in all US counties, while the mean O3 levels in the IHS counties were higher than the US counties. Multivariable Cox regressions revealed a positive association between dementia and county-level O3 with a hazard ratio of 1.24 (95% CI: 1.02-1.50) per 1 ppb standardized O3. PM2.5 and NO2 were not associated with dementia risk after adjusting for all covariates. (4) Conclusions: O3 is associated with a higher risk of dementia among American Indians.
摘要:
(1)背景:美国印第安人不成比例地受到空气污染的影响,痴呆的重要危险因素.然而,很少有研究调查空气污染对美国印第安人痴呆症风险的影响。(2)方法:本回顾性队列研究包括2007年55岁以上的26,871名美洲印第安人,平均随访3.67年。从土地利用回归模型下载县级平均空气污染数据。使用印度卫生局(IHS)国家数据仓库和相关管理数据库中的ICD-9诊断代码确定了全因痴呆症。Cox模型用于检查空气污染与痴呆症发病率的关系,调整共同暴露和潜在的混杂因素。(3)结果:IHS县的平均PM2.5水平低于美国所有县,而IHS县的平均O3水平高于美国县。多变量Cox回归显示,痴呆症与县级O3之间存在正相关,每1ppb标准化O3的风险比为1.24(95%CI:1.02-1.50)。在调整所有协变量后,PM2.5和NO2与痴呆风险无关。(4)结论:在美洲印第安人中,O3与较高的痴呆风险有关。