Kim Hyunmin, Noh Juhwan, Noh Young, Oh Sung Soo, Koh Sang-Baek, Kim Changsoo
Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, South Korea.
Division of Health Systems Management and Policy, University of Memphis School of Public Health, Memphis, TN, United States.
Front Public Health. 2019 Dec 10;7:375. doi: 10.3389/fpubh.2019.00375. eCollection 2019.
Given a fast-growing aging population in South Korea, the prevalence of cognitive impairment in elderly is increasing. Despite growing evidence of air pollution exposure as one of the risk factors for declining cognition, few studies have been conducted on gender difference in the relation of cognitive function associated with outdoor air pollution. The aim of this study is to investigate the effect modification of gender difference in the association between cognitive function and air pollutant exposure (PM, PM, and NO). The study focused on elderly, and the resulting sample included 1,484 participants aged 55 and older with no neurologic diseases, recruited from the four regions in Korea (Seoul, Incheon, Pyeongchang, and Wonju). We used the Mini-Mental State Examination (MMSE) score (with the conventional cut-off point "23-24") to assess cognitive decline as the primary outcome of the study. Air pollution data used in this study were based on the 5-year average of predicted PM and NO concentrations, as well as the 2015 average PM concentration. Additionally, a survey questionnaire was utilized to obtain information about general health assessment. To explore gender differences in the effects of air pollution exposure on cognitive function, we used penalized logistic regression, negative binomial regression, and generalized linear mixed model analyses. Subgroup analyses were also performed by the geographic location of residence (metropolitan vs. non-metropolitan). We found that women than men had a higher risk for decreased cognitive function associated with increased exposure to PM and PM, respectively, even after adjustments for confounding factors (OR 1.01 [95%CI 1.00-1.03] in PM; OR 1.03 [95%CI 1.01-1.07] in PM). After stratification by metropolitan status, we also found that the adverse effect of NO exposure on cognitive function was higher in women than men [OR 1.02 [95%CI 1.00-1.05] in metropolitan; OR 1.12 [95%CI 1.04-1.20] in non-metropolitan]. Notably, the magnitude of the effect sizes was greater among those in non-metropolitan regions than metropolitan ones. Although our findings suggest that the adverse effects of outdoor air pollution on cognitive function appeared to be higher in women than men, this should be tentatively reflected due to some limitations in our results. While additional research is warranted to confirm or dispute our results, our findings suggest an indication of the need for developing and implementing prevention or interventions with a focus on elderly women with increased risk for air pollution exposure.
鉴于韩国老年人口迅速增长，老年人认知障碍的患病率正在上升。尽管越来越多的证据表明接触空气污染是认知能力下降的风险因素之一，但关于室外空气污染与认知功能关系中的性别差异的研究却很少。本研究的目的是调查性别差异在认知功能与空气污染物暴露（PM、PM和NO）之间关联中的效应修正作用。该研究聚焦于老年人，最终样本包括从韩国四个地区（首尔、仁川、平昌和原州）招募的1484名55岁及以上无神经系统疾病的参与者。我们使用简易精神状态检查表（MMSE）评分（采用传统临界值“23 - 24”）来评估认知能力下降情况，将其作为研究的主要结果。本研究中使用的空气污染数据基于预测的PM和NO浓度的5年平均值以及2015年PM浓度的平均值。此外，还利用一份调查问卷来获取有关一般健康评估的信息。为了探究空气污染暴露对认知功能影响中的性别差异，我们使用了惩罚逻辑回归、负二项回归和广义线性混合模型分析。还按居住地理位置（大城市与非大城市）进行了亚组分析。我们发现，即使在对混杂因素进行调整后，女性与男性相比，分别因接触PM和PM增加而认知功能下降的风险更高（PM中OR为1.01 [95%CI 1.00 - 1.03]；PM中OR为1.03 [95%CI 1.01 - 1.07]）。按大城市状况分层后，我们还发现，女性因接触NO对认知功能的不利影响高于男性[大城市中OR为1.02 [95%CI 1.00 - 1.05]；非大城市中OR为1.12 [95%CI 1.04 - 1.20]]。值得注意的是，非大城市地区人群的效应大小幅度大于大城市地区人群。尽管我们的研究结果表明室外空气污染对认知功能的不利影响在女性中似乎高于男性，但由于我们结果存在一些局限性，这一点应暂且予以考虑。虽然需要进一步研究来证实或反驳我们的结果，但我们的研究结果表明有必要制定并实施以空气污染暴露风险增加的老年女性为重点的预防或干预措施。
