Holguín Fernando, Téllez-Rojo Marta M, Hernández Mauricio, Cortez Marlene, Chow Judith C, Watson John G, Mannino David, Romieu Isabelle
Emory University School of Medicine, Atlanta, GA 30335, USA.
Epidemiology. 2003 Sep;14(5):521-7. doi: 10.1097/01.ede.0000081999.15060.ae.
Suspended particles and ozone have been associated with varying degrees of cardiac autonomic dysfunction.
In Mexico City, residents from a nursing home underwent heart rate variability analysis every other day for 3 months. Indoor and outdoor PM2.5 (particulate matter less than 2.5 mm in diameter) were measured daily at the nursing home. Levels of ozone and other atmospheric pollutants were obtained from a nearby automated monitoring station.
Of the initial 42 screened participants, 34 (81%) were followed during the study period. The 24-hour average levels of indoor PM2.5 ranged from 15 to 67 micro g/m3, and outdoor PM2.5 ranged from 9 to 87 micro g/m3. Daily 1-hour maximum ozone levels ranged from 47 to 228 ppb. After adjusting for age and heart rate, we observed a strong decrease in the high frequency component of heart rate variability and the average 24-hour concentrations of PM2.5. Participants with hypertension had considerably larger reductions in their HF-HRV (high frequency-heart rate variability) component in relation to both ozone and PM2.5 exposure.
Our results suggest that ambient levels of PM2.5 and ozone can reduce the high-frequency component of heart rate variability in elderly subjects living in Mexico City and that subjects with underlying hypertension are particularly susceptible to this effect.
悬浮颗粒和臭氧与不同程度的心脏自主神经功能障碍有关。
在墨西哥城，一家养老院的居民每隔一天进行一次为期3个月的心率变异性分析。每天在养老院测量室内和室外的PM2.5（直径小于2.5毫米的颗粒物）。臭氧和其他大气污染物的水平从附近的自动监测站获取。
在最初筛选的42名参与者中，34名（81%）在研究期间接受了跟踪。室内PM2.5的24小时平均水平在15至67微克/立方米之间，室外PM2.5在9至87微克/立方米之间。每日1小时最大臭氧水平在47至228 ppb之间。在调整年龄和心率后，我们观察到心率变异性的高频成分和PM2.5的24小时平均浓度大幅下降。高血压参与者的高频心率变异性成分相对于臭氧和PM2.5暴露的下降幅度要大得多。
我们的结果表明，墨西哥城老年居民环境中的PM2.5和臭氧水平可降低心率变异性的高频成分，且患有原发性高血压的受试者对此效应尤为敏感。
