Daily variation of particulate air pollution and poor cardiac autonomic control in the elderly
Daily variation of particulate air pollution and poor cardiac autonomic control in the elderly
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DOI：
10.2307/3434393
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发表时间：
1999-07-01
影响因子：
10.4
通讯作者：
Zweidinger, R
中科院分区：
文献类型：
--
作者：
Liao, DP;Creason, J;Zweidinger, R
在最近的一些研究中，颗粒物空气污染（PM）与心血管疾病死亡率有关。这种关联的病理生理机制正在研究中。低心率变异性是心脏自主控制不良的标志，与心肌梗死和心源性猝死的高风险相关。为了探讨PM-心血管疾病死亡的可能机制，我们连续3周检测了26名老年人（平均年龄81岁）对PM每日变化的心脏自主神经反应。在临床试验前，使用几种标准化方法测量参与者住所内（室内PM2.5）和室外（室外PM2.5和PM2.5-10）的24小时平均PM浓度。收集静息、仰卧、6 min R-R间隔数据，估计正常R-R间隔（SDNN）高频（0.15 ~ 0.40 Hz）和低频（0.04 ~ 0.15 Hz）功率和标准差作为心脏自主控制指标。参与者特定的低心率变异性天数被定义为高频指数在研究期间低于个体高频分布的前五分之一的天数。室内PM2.5浓度为15 μ g/m(3)为高污染日。结果表明，低心率变异性高频率在高污染天数（相对于不高污染天数）的比值比（95%置信区间）为3.08（1.43,6.59）。混合模型的β系数（标准误差）分别为-0.029（0.010）、-0.027（0.009）和-0.004(0.003)，用于评估室内PM2.5与对数变换高频、低频和SDNN之间的定量关系。这项首次关于心脏自主控制对PM2.5日变化反应的研究表明，PM2.5水平升高与心脏自主控制降低有关，这表明PM与心血管疾病死亡率之间可能存在机制联系。
Particulate matter air pollution (PM) has been related to cardiovascular disease mortality in a number of recent studies. The pathophysiologic mechanisms for this association are under study. Low heart rate variability, a marker of poor cardiac autonomic control, is associated with higher risk of myocardial infarction and sudden cardiac death. To address the possible mechanisms for PM-cardiovascular disease mortality, we examined the cardiac autonomic response to daily variations in PM in 26 elderly (mean age 81) individuals for 3 consecutive weeks. Several standardized methods were used to measure 24-hr average PM concentrations prior to the clinical test inside (indoor PM2.5) and immediately outside (outdoor PM2.5 and PM2.5-10) of participants' residences. Resting, supine, 6-min R wave to R wave (R-R) interval data were collected to estimate high frequency (0.15-0.40 Hz) and low frequency (0.04-0.15 Hz) powers and standard deviation of normal R-R intervals (SDNN) as cardiac autonomic control indices. Participant-specific lower heart rate variability days were defined as days for which the high-frequency indices fell below the first tertile of the individual's high-frequency distribution over the study period. Indoor PM2.5 > 15 mu g/m(3) was used to define high pollution days. Results show that the odds ratio (95% confidence interval) of low heart rate variability high frequency for high (vs. not high) pollution days was 3.08 (1.43, 6.59). The beta-coefficients (standard error) from mixed models to assess the quantitative relationship between variations in indoor PM2.5 and the log-transformed high frequency, low frequency, and SDNN were: -0.029 (0.010), -0.027 (0.009), and -0.004 (0.003), respectively. This first study of cardiac autonomic control response to daily variations of PM2.5 indicates that increased levels of PM2.5 are associated with lower cardiac autonomic control, suggesting a possible mechanistic link between PM and cardiovascular disease mortality.