Personal coronary risk profiles modify autonomic nervous system responses to air pollution.
OBJECTIVE
We investigated whether PM2.5-mediated autonomic modulation depends on individual coronary risk profiles.


METHODS
Five-minute average heart rate (HR) and heart rate variability (HRV, including standard deviation of normal-to-normal intervals [SDNN], square root of the mean squared differences of successive NN intervals [rMSSD], high frequency [HF]) were measured from 24-hour ambulatory electrocardiograms, and personal PM(2.5) exposures were monitored in a prospective study of 10 male boilermakers (aged 34.3 +/- 8.1 years). We used the Framingham score to classify individuals into low (score = 1-3) and high (score = 5-6) risk categories. Mixed-effect models were used for statistical analyses.


RESULTS
Each 1-mg/m(3) increase in the preceding 4-hour moving average PM(2.5) was associated with HR increase (5.3 beats/min) and HRV reduction (11.7%, confidence interval [CI] = 6.2-17.1% for SDNN; 11.1%, CI = 3.1-19.1% for rMSSD; 16.6%, CI = 1.5-31.7% for HF). Greater responses (2- to 4-fold differences) were observed in high-risk subjects than in low-risk subjects.


CONCLUSIONS
Our study suggests that adverse autonomic responses to metal particulate are aggravated in workers with higher coronary risk profiles.
Chen
Jiu-Chiuan
JC
Harvard School of Public Health, 655 Huntington Avenue, Boston, MA 02115, USA.
Stone
Peter H
PH
Verrier
Richard L
RL
Nearing
Bruce D
BD
MacCallum
Gail
G
Kim
Jee-Young
JY
Herrick
Robert F
RF
You
Jinhong
J
Zhou
Haibo
H
Christiani
David C
DC
D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects*; D001341:Autonomic Nervous System / Q000502:physiology*; D002318:Cardiovascular Diseases; D015331:Cohort Studies; D015716:Electrocardiography, Ambulatory; D006306:Health Surveys; D006339:Heart Rate; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects*; D052638:Particulate Matter / Q000009:adverse effects*; D012307:Risk Factors; D014896:Welding
D000395:Air Pollutants, Occupational; D052638:Particulate Matter