Effect of Ambient Particulate Matter on Heart Rate Variability in Susceptible Population

• Main Authors: Nan-Ting, Chen, 陳南廷
• Other Authors: 詹長權
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/15727767524312108144

碩士 === 國立臺灣大學 === 職業醫學與工業衛生研究所 === 91 === Objective: We assessed the relationship between particulate matter of different size and heart rate variability (HRV) in susceptible population and healthy controls. Methods: We recruited 29 susceptible adults and classified them to two subgroups. The first subgroup was above 65yrs with or without disease, and the second subgroup was from 40-75 yrs with coronary heart disease(CHD) or other CHD risk factors(Hypertension, Hyperlipidemia, and diabetic). In addition, we also recruited 9 healthy controls. In order to evaluate whether particulate matter(PM) will affect HRV, we measured continuously each subject’s 24-hour electrocardiographics by PacerCorder, and particle exposure by GRIMM portable dust monitor. We used linear mixed-effects model to estimate the relationship between particle exposure and physiological responses, including heart rate and the time-domain measures of HRV, such as SDNN, r-MSSD, pNN50, and the frequency domain measures of HRV, such as LF, HF, LF/HF, Total power. The response variables including heart rate, SDNN, r-MSSD, LF, HF, Total power were log10-transformed. Results: In the susceptible population, after adjusting for sleep, gender, age, body mass index(BMI), current smoker, β-block medicine, disease, temperature and relative humidity, we found significant association between particle exposure and HRV parameters in susceptible population. When 4-hour moving PM10 average increased 100μg/m3, the percentage changes of heart rate, SDNN, r-MSSD, pNN50, LF, HF, LF/HF, Total power were 0.49％, -4.96％, -6.95％, -0.84％, -6.86％, -6.02％, -0.38% and -4.73％. When 4-hour moving PM2.5 average increased 100μg/m3, the percentage changes of heart rate, SDNN, r-MSSD, pNN50, LF, HF, LF/HF, Total power were 0.44％, -5.44％, -7.76％, -0.96％, -7.54％, -6.43％, -0.41％, -5.09％. When 4-hour moving PM1 average increased 100μg/m3, the percentage changes of heart rate, SDNN, r-MSSD, pNN50, LF, HF, LF/HF, Total power were. 0.50％, -6.21％, -8.87％, -1.09％m, -8.53％, -7.33％, -0.42％, -5.71％. In healthy controls, after adjusting for sleep, gender, age, BMI, temperature and relative humidity, we found only a few significant associations between particle exposure and parameters of HRV. And most of them were positive. Conclusions: In the susceptible population, our findings suggested that particles might have short-term effects and delay effects on time and frequency domains of HRV. Furthermore, the fine particle is more prominent than coarse particle. The mechanism of such effects was related to autonomic modulation and inflammation after exposure. In healthy controls, we considered that particles would not cause poor health when they exposured to low particle concentrations.